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santiniuk
12-08-2004, 04:26 PM
Hi All, :)

Like a lot of people on here, this forum has captured my interest.

I now no longer pass heaps of scrap metal without wondering what use they can be used for....

I'm from the U.K and would like to pass my thanks to Alan at www.fromorbit.com as his Picstep controller design will be the 1st elements of my project.

It's early days but hopefully writing my log here will be an incentive to keep going...

Enough rambling.... thanks for having me on here....

santiniuk
12-08-2004, 04:37 PM
Stage 1

I need to make 3 controller boards and 1 interface board.

Had some spare photo-resist board so after printing the artwork on a HP laserjet printer to clear film It was time to hunt out the UV exposure box.

Some of the pads are not as thick as I would like, especially as they need to be hand drilled.

Photoresist was not too bad so I will continue.

santiniuk
12-08-2004, 04:48 PM
After exposing the 4 boards to UV light, the exposed resist was removed.
Not one of my favourite jobs !

The boards were then placed in the etching tank and overall I was quite happy with the track detail.

After washing the boards I hunted for some tin plating solution I knew I had somewhere.....

This certainly helps when soldering to the boards and it stops the copper contamination.

So with 4 boards etched I call it a day... I will drill them tomorrow. Oh how I will enjoy that....

(As a side note can anyone recommend a pcb prototyping company in the UK ?)

End of day 1 :)

Image of boards after using the tin plating solution

arvidb
12-09-2004, 08:12 AM
(As a side note can anyone recommend a pcb prototyping company in the UK ?)

http://www.pcb-pool.com/ppuk/info.html

Arvid

BobLWeiss
12-09-2004, 08:37 AM
I must say they came out really good. I am also in the process of making these boards although I wanted some more bells and whistles so I redesigned the layout but still using the same firmware and basic design he layed out. I am interested to see how they perform when you get that far. What size motors are you using for this? What size power supply?

MrBean
12-11-2004, 08:29 AM
I'm also building these boards for my router. I'm trying to, "isolation mill" the tracks on the boards using my CNC. Still some work to do on them to get them usable. You can check out the progress at:

http://www.terry-is.f2s.com/


Regards Terry.....

BobLWeiss
12-11-2004, 09:26 AM
Well I started etching the driver boards and they came out really well. I used the "toner transfer" method to make them which has to be the best way to make a board I have ever come across. (that is until I get my CNC working :boxing: )

http://www.boblweiss.com/CooperEtch.jpg

And then I tinned them. I made all 3 drivers boards and the breakout board.

http://www.boblweiss.com/TinnedBoards.jpg

Thanks Alan for the design!

santiniuk
12-12-2004, 12:49 PM
I should know better !

Things never go to plan. Somewhere in my workshop is a large collection of pcb drills. The problem is I searched high and low and didn't find them. I ordered a few mail order after a frustrating hour or two.

Unfortunately these have still not turned up. No progress at all.

I have found a few useful looking items at work. Linear rails and what looks like a sealed ball-screw assembly. I'll grab some pics and post shortly.

To answer a few questions posted.

Thanks for the link arvidb. Will check this out for future pcb's. I mailed one company who are quite local to me. They have quoted £12 approx per pcb. If anyone is interested I can pass on the details.


@ BobLWeiss, I'm afraid I have not really planned this project very well. At this stage I knew that the Picstep controller would be suitable, I'm more biased to electronics than mechanical construction so I thought, Get the controllers built as an incentive and then research the mechanical bits. I'm still at the research stage :)

The toner transfer method certainly looks like it produces good quality boards. I have never used this method but would like to understand it a bit more. Time to ask Google how it's done.

(If I make any more of the Picstep boards I will change a few pads as some are on the small side.)

I will be interested how your construction goes. Maybe you can keep me on the right track !

@MrBean, Really enjoyed visiting your site. I have often wanted to do pcb's in the method you are using. Good to see someone else in the UK. (North East here).

Thanks all,

(Alan if your reading any of this. Your artwork still shows v2.0 for the V2.1 boards. - I thought I had etched the wrong ones !)

BobLWeiss
12-12-2004, 12:57 PM
You can find more about the toner transfer method by going to the yahoo-group for homemade pcb's and also here:

Toner Transfer Method (http://www.fullnet.com/u/tomg/gooteepc.htm)

I am also waiting on bits to arrive so I can drill out those boards and begin contrustion of the drivers. I have most of the machine finsihed and can post pictures later on when I get the camera back..(wife...hehe)

Garfield2
12-12-2004, 04:14 PM
(Alan if your reading any of this. Your artwork still shows v2.0 for the V2.1 boards. - I thought I had etched the wrong ones !)

Doh! I'll fix that now. I've also got to upload my latest firmware that fixes a small bug. It's nothing major and almost completely cosmetic but it should be fixed (I brain faded and used a call instead of a goto in the main loop, so it just overflowing the stack each iteration. No harm done).

I'm glad you guys have built these boards with such furvor. It's impressive! Let me know if you have any problems or if you need help. PICStep has been throughly tested, but you never know what happens in different situations.

Thanks,
Alan.

santiniuk
12-12-2004, 05:12 PM
I have just spent a good 10 minutes on the site you posted BobLWeiss, quite impressive !

This is certainly a method I will investigate in future. Can you comment on how easy / successful it is ? From the images you posted it looks great.

It sounds like your well ahead of me if your machine is built. I look forward to seeing the pics. (And grab some ideas...)

@Alan,

Good to see the master is watching ! Thanks again. Will post any queries here.

Cheers

BobLWeiss
12-12-2004, 06:15 PM
Alen, what kind of speed (rpm's) are you getting with your design? I built one as a test and I cannot get it to move fast at all. I changed the source to make it run continuoulsy so I can test my hardware and I had to put a delay loop in between each step (40ms). With this delay its painfully slow. It could be something on my end that is wrong but I just wanted to see what speed you were able to get by using the computer to generate steps (TurboCNC, etc). Thanks!

BobLWeiss
12-12-2004, 06:20 PM
Can you comment on how easy / successful it is ? From the images you posted it looks great.

To me it can't be any easier, after printing it out (I use Staples Picture Paper and haven't tried anything else), I press a hot iron on it for about 7 minutes and move it around to make sure I get every inch. After that I let it cool for about 5 minutes then place it in warm water with some dish soap in it. I let it sit for about 15 minutes and peel the first layer of paper off. Then soak some more and do this until you get 90% of the paper off (total of 30-45 minutes). I then use an eraser on a number 2 lead pencil and rub off the remaining bits (make sure you do this in the water and not dry).

Sometimes it rubs off a little piece of toner so you will need to look at it with a magnifying glass and touch up the spot(s) with a fine pointed Sharpie. Now your ready to etch away. I can get as small as 10mil traces with 10mil spacing between them. I haven't tried any smaller yet but I'm sure if your careful it can be done.

Bob

Garfield2
12-12-2004, 06:20 PM
Andy, what kind of speed (rpm's) are you getting with your design? I built one as a test and I cannot get it to move fast at all. I changed the source to make it run continuoulsy so I can test my hardware and I had to put a delay loop in between each step (40ms). With this delay its painfully slow. It could be something on my end that is wrong but I just wanted to see what speed you were able to get by using the computer to generate steps (TurboCNC, etc). Thanks!

Andy or Alan?

Umm I have a video on my website of the PICStep running a motor via TurboCNC on a crappy Celeron 300. I guess the motor was turning at about 1000 - 2000 rpm.

That's if you're talking about PICStep that is..

I'm confused. :)

BobLWeiss
12-12-2004, 06:22 PM
I ment Alen, sorry. Yeah I saw that video..so it must be my mistake somewhere. I am anxious to get one of them completely built and try it out using TurboCNC.

Garfield2
12-12-2004, 06:32 PM
I ment Alen, sorry.

Closer! It's Alan. :)


Yeah I saw that video..so it must be my mistake somewhere. I am anxious to get one of them completely built and try it out using TurboCNC.

Silly question, you using a 20MHz resonator/crystal setup? I ask as you mentioned you've modified the design a bit and I'm wondering if your clock is one hundred percent.

Cheers,
Alan.

BobLWeiss
12-12-2004, 06:57 PM
Closer! It's Alan. :)

Ignore my stupidity...sorry again. I am bad with names, both in person and in type. :(



Silly question, you using a 20MHz resonator/crystal setup? I ask as you mentioned you've modified the design a bit and I'm wondering if your clock is one hundred percent.


Yes, I am using a 20Mhz crystal and its running 100%. I checked it with a frequency meter. I tried to speed it up by making the loop 30ms and it won't run at that interval. It starts to work at 40ms and slower. I am not going to worry too much about it unless it does the same thing on the new boards (which I didn't modify at all as you can see from the pictures I posted.) I am waiting on the resonators and drill bits so I can put those together then I can fully test it using the computer to drive it.

MrBean
12-12-2004, 07:15 PM
Here's some piccys of my freshly CNC milled board. No holes yet, as it was just a test to see how the modified track layout would work. Looks like it should be usable.

Regards Terry.....

Garfield2
12-12-2004, 07:35 PM
Yes, I am using a 20Mhz crystal and its running 100%. I checked it with a frequency meter. I tried to speed it up by making the loop 30ms and it won't run at that interval. It starts to work at 40ms and slower. I am not going to worry too much about it unless it does the same thing on the new boards (which I didn't modify at all as you can see from the pictures I posted.) I am waiting on the resonators and drill bits so I can put those together then I can fully test it using the computer to drive it.

Hmm weird, by my ruff calculations with a 16KHz pulse you'd get around 600rpm with a 1.8degree motor at 1/8th step.

16000 steps per second
1600 steps per 360 (360 / (1.8 / 8))

16000 / 1600 = 10 revs per second
10 * 60 seconds = 600rpm

I've had my motors up to at least that high.

Also by my calculations using the 200ns instruction time would mean one step per 0.0135 milliseconds with the current firmware. This could theoretically be achievable by the 20MHz PIC.

1000 ms / 0.0135 = 74074 steps per sec
1600 steps per 360 (360 / (1.8 / 8))

74074 / 1600 = 46 rev per second
46 * 60 seconds = 2760 rpm

So what does it do with a 40ms delay that's different from the 30ms? Are the motors singing like the current limiting is working? Also what drive current do you have set? Can you email me your source code for your driver so I can see if there isn't something else going on.

Cheers,
Alan.

BobLWeiss
12-12-2004, 07:42 PM
I just emailed you the code. As far as the motors singing, all it did was step, step, step, step...sort of like 4 steps per second if that. I know something is not right as it should got alot faster than that. I used a 10K resistor for 2amps per phase and I used a 24vdc powersupply. If I changed it to 30ms it does absolutly nothing. No noise, nothing.

Garfield2
12-12-2004, 08:03 PM
I just emailed you the code. As far as the motors singing, all it did was step, step, step, step...sort of like 4 steps per second if that. I know something is not right as it should got alot faster than that. I used a 10K resistor for 2amps per phase and I used a 24vdc powersupply. If I changed it to 30ms it does absolutly nothing. No noise, nothing.

Hmm the fact the motors aren't singing leads me to believe that something isn't right with the oscillators the LMD's use (R1,R3, C1,C3). These set the switching frequency for the current limiting of the LMD's. Normally when the motor is just sitting without any stepping and the coils engergised the motors will sing a little (more so when they're in a 1/8 step quadrant).

Do you have a CRO or a frequency meter?

If so, check the RC pins on the LMD's to see they're oscillating at about 19KHz, also check the LSB (RA0, RB2) pins (and the others if you want) of the PIC while running the step pulses, you should see quite a bit of action there with a CRO. If not, something is not right with the firmware you're using. I'll have a look at the code when I get some spare time.

Cheers,
Alan.

BobLWeiss
12-12-2004, 08:24 PM
I think I see one problem, your schematic calls for a 2.2nf cap and I used a 2.2uf. I just noticed that so that could be it since it messed up the timing circuit. I do have a meter and will check it out. Don't worry about the code part since it was only for testing the hardware. I will have the "real' boards built by this weekend and it should be good. I am also using your original code from the website too. Thanks for taking the time to check it out for me though. Back to the original intent of this post...sorry for "hijacking" it. Hopefully it helps someone out.

Here is a picture of my Z axis with motor. I got it off ebay, custom built to my specs...nice guy and great deal:

santiniuk
12-13-2004, 05:03 PM
Finally received my pcb drill's today and amazingly managed to drill all four boards without snapping a bit ! That's got to be a first maybe things are looking up :)

I have all the components now to build the boards except the damn resonator !

If anyone can recommend a source for a 20MHz 3 pin resonators in the U.K I would be very grateful. R.S and Farnell don't have them (Or I cannot find them).

I need to sit back now and see what Stepping motor's I require.

What else...

I upgraded the firmware of my Microchip Picstart programmer. This required a new I.C in the past but they released a small module that replaces this. This module is flash upgradable via the release of MPLAB IDE. So hopefully this will meet my needs for a while.

I downloaded Alan's firmware v1.01 code for the micro's as well.

That Z axis looks top quality Bob, very professional.

Mr Bean, good to see the progress on your milled boards. I'm interested how you create the cutter path from pcb artwork. I can imagine this being a very useful tool.

Cheer's
:)

Garfield2
12-13-2004, 05:10 PM
I have all the components now to build the boards except the damn resonator !

If anyone can recommend a source for a 20MHz 3 pin resonators in the U.K I would be very grateful. R.S and Farnell don't have them (Or I cannot find them).


http://www.dontronics.com/ (http://www.dontronics.com/cat_hard_micro_xtl.html)

He's a really nice guy and ships to anywhere in the world. Plus for 20MHz resonators they're pretty cheap to buy and ship from anywhere in the world really.



I downloaded Alan's firmware v1.01 code for the micro's as well.


Cool, it's only minor. But you might as well upgrade to it. :)



Mr Bean, good to see the progress on your milled boards. I'm interested how you create the cutter path from pcb artwork. I can imagine this being a very useful tool.


I believe he did it very skillfully by hand in photoshop. I'd be very interested to see if it works. Perhaps I should start using polygons for traces rather than tracks and pads.. :)

Alan.

MrBean
12-13-2004, 05:46 PM
I have also been looking for the 20 Mhz Resonator. I decieded I'd buy the surface mount ones from Farnell and mount them under the board. Lead pitch is still the same. Other than that It's buying from the US.


http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=648190&N=401




Regards Terry..... http://www.terry-is.f2s.com/

BobLWeiss
12-13-2004, 05:47 PM
Finally received my pcb drill's today and amazingly managed to drill all four boards without snapping a bit ! That's got to be a first maybe things are looking up :)

That's funny, I received my bits today as well....I just finished drilling the BOB board and one of the stepper controllers....I have everything except the caps and resonator...waiting on Mouser order...should be tomorrow.



I upgraded the firmware of my Microchip Picstart programmer. This required a new I.C in the past but they released a small module that replaces this. This module is flash upgradable via the release of MPLAB IDE. So hopefully this will meet my needs for a while.

I just bought one on ebay an it is a revision 4 model...a little older. Why did you upgrade? Doesn't it do the 628's already? What revision did you have before you upgraded? How much was it to get the new chip?


That Z axis looks top quality Bob, very professional.

Thanks...I can't take the credit as I didn't build it but it is quite nice. He is making me a X and Y axis for NEMA 23's too...I am going to use this for PCB work and the other one I am building now (bigger) for wood, metal etc...

BobLWeiss
12-13-2004, 05:48 PM
For the US you can get them from ALL ELECTRONICS (http://www.allelectronics.com)

santiniuk
12-15-2004, 02:08 PM
It looks like the wrong time of year to make progress :rolleyes:

Too many Christmas parties, works doo's and hangovers... :)

To answer the Picstart upgrade.

The details are here :-

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en010069

I had already upgraded to the last revision of the firmware v3.11 prior to the upgrade mentioned above.

If anyone want's this I have two v3.11 Rom's free to anyone.

The upgrade was purchased from Farnelll electronics in the U.K

http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=5010925&N=401

It's simply a matter of removing 4 screws, unplugging an I.C and dropping in a small daughter board in the original I.C socket. 2 mins work.

Price £15.94

We use the programmers at work so they cover the upgrade cost's.
(I was tired of seeing the upgrade messages in the MPLAB software!)


I have been told that a 20Mhz Crystal would be o.k for the resonator. These I can source easily so my intentions are to purchase these instead of resonators. (I hope this is correct)


Interested to see how the boards are coming along Mr Bean. Have you made progress ?

Lastly, Alan if you have a spare moment can you take some pictures of the interface board. I'm struggling to make out some of the components, i.e switch type, connectors etc.
Thanks !

Cheers all,

MrBean
12-15-2004, 02:39 PM
The boards are not comming along at the minute. Waiting to get some spare time. Work and a new baby have to come first. I'm purchasing parts while I wait. I have some parts ordered and I'll be ordering the remainder before the weekend.

Santiniuk. I have ordered 40 X 3 pin 20 Mhz resonators. If they turn up soon and you can hang on, I can send you 3. I know they're pretty hard to find over here. (UK).

Hopefully I'll have 3 boards machined and drilled over the weekend. I'll post some pictures, when I've made some progress.


Regards Terry.....
http://www.terry-is.f2s.com

MrBean
12-15-2004, 02:41 PM
Sorry. I forgot, about the resonators. They are not the SMD one's I was going to buy. They are the same type as shown on Alan's PICStep boards.

Regards Terry.....

santiniuk
12-15-2004, 02:43 PM
Thanks for the offer Mr Bean or do you prefer Terry :)

Will certainly cover any costs for the correct parts.

I know what you mean about time. I have Twins. Just gone 4 and it's non stop !

This is one of those projects that I won't be rushing so this may be a long thread.....

Regards,

ViperTX
12-15-2004, 02:43 PM
I have no idea what this circuit looks like but, generally resonators are self contained and crystals (not crystal drivers) require a few external capacitors to get them oscillating....

BobLWeiss
12-15-2004, 02:48 PM
I have no idea what this circuit looks like but, generally resonators are self contained and crystals (not crystal drivers) require a few external capacitors to get them oscillating....


The one that Alan used for his circuit is the 3 leaded one that has built in capacitors. I am getting them for $1 a piece in the US.

MrBean
12-15-2004, 04:27 PM
Thanks for the offer Mr Bean or do you prefer Terry :)

Will certainly cover any costs for the correct parts.

I know what you mean about time. I have Twins. Just gone 4 and it's non stop !

This is one of those projects that I won't be rushing so this may be a long thread.....

Regards,


Either name is fine.

I got a really good deal on 40, and I only need 4 at most, maybe a few for spares too. I'll let you know when/if, they arrive and I'll post you some for free.

Regards Terry.....

santiniuk
12-16-2004, 03:59 PM
Top Stuff Terry. Appreciated :)

@Viper - Thanks for the tip. I'll look into the external cap's as Crystals are due tomorrow and I will be itching to test them.

Can someone confirm the value of Resistors R1-R5 on the interface board. They look like pull-ups.

Also the switches, I'm not entirely sure what all 14 are required for. Can someone please clarify ?

Lastly on the control boards I have some 470pf caps instead of the 500pf specified will these be ok ?

Thanks all,

ViperTX
12-16-2004, 04:18 PM
Top Stuff Terry. Appreciated :)

@Viper - Thanks for the tip. I'll look into the external cap's as Crystals are due tomorrow and I will be itching to test them.

Can someone confirm the value of Resistors R1-R5 on the interface board. They look like pull-ups.

Also the switches, I'm not entirely sure what all 14 are required for. Can someone please clarify ?

Lastly on the control boards I have some 470pf caps instead of the 500pf specified will these be ok ?

Thanks all,

Look at the tolerance on the 470 pf...the 500 pf should work. What does the schematic look like.

Garfield2
12-16-2004, 04:42 PM
Can someone confirm the value of Resistors R1-R5 on the interface board. They look like pull-ups.



Indeed, they're 10K. Just a normal pull-up resistor




Also the switches, I'm not entirely sure what all 14 are required for. Can someone please clarify ?



The 2x2 blocks are for setting the modes of the controllers (Full, Half, 1/4, 1/8th), they're just jumper blocks. The other six are just general inputs for home switches etc. If you don't need them you can just leave them out along with the pull-up resistors. The "CONN7" block is an output block for 3 pins on the parallel port which you can use to trigger your own relay drivers to turn on/off motors/pumps/routers.




Lastly on the control boards I have some 470pf caps instead of the 500pf specified will these be ok ?



470pF will be fine to replace the C2/C4 capacitors. The only critical value there is the 2.2nF's of C1/C3 as they set the RC up for the PWM timing.

Also ignore the error in the schematic for the values of R2/R4 these two resistors set the current limit for each coil and should be set the same using this equation to work out their values :-

resistor value = 20000 / coil current

eg 20000 / 0.7A = 28K


The interface board uses the same screw terminal block of the controller boards. The 2x2 are just 2x2 IDC pins.


Cheers,
Alan.

PS quite busy organising new infrastructure at work, so I cannot monitor these forums or my email for the next few weeks. Thanks.

santiniuk
12-16-2004, 04:49 PM
As always help when needed. Thank's guy's.

I appreciate the assistance.

Cheers

BobLWeiss
12-16-2004, 05:47 PM
I used a 470pf cap as well. I cannot find a 500pf cap anywhere and believe me I looked. I don't belive they make one. It should be ok.

The 5 resistors are pullups for the external input switches. The reason for so many is because the lines are available so why not use them? (I'm guessing). I am using them for home and limit switches.

santiniuk
12-17-2004, 11:19 AM
Not guite 100% but nearly there....

Missing a couple of components but got all 4 boards built to 99%

Not going to have a chance to do much this weekend so it will be Monday before much more is done.

I have the bits to make the IDC leads and will make these on Monday.

I messed a bit with my camera trying to get some decent pic's. Not great, maybe when you have some time Alan you can give a few pointers on how to get good closeup shots.

I must dust off the boards before I take pics next time :rolleyes:
Cheers,

BobLWeiss
12-17-2004, 12:27 PM
Looks good...your pictures are fine the way they are now.

I am at the same stage as well..they messed up my order so I have to wait till Monday to get the rest of my parts...its a race to see who's done first... :cheers:

Bob

Garfield2
12-17-2004, 04:06 PM
Not guite 100% but nearly there....

Missing a couple of components but got all 4 boards built to 99%

Not going to have a chance to do much this weekend so it will be Monday before much more is done.

I have the bits to make the IDC leads and will make these on Monday.


Looks excellent. Making massive progress! Well done.



I messed a bit with my camera trying to get some decent pic's. Not great, maybe when you have some time Alan you can give a few pointers on how to get good closeup shots.


Unfortunately it's called a really expensive camera and a really good 35mm lens. I have a Canon 10D and I used a Canon EF 28mm f/1.8 lens. But! you can get really good results with everyday digital cameras. My mate Dan has written a very good basic photographic tutorial at :

http://www.dansdata.com/ (http://www.dansdata.com/phototute.htm)




I must dust off the boards before I take pics next time :rolleyes:
Cheers,

Guilty of that too!

http://www.fromorbit.com/projects/picstep/images/PICStep-Pro-Board2.jpg

-A

BobLWeiss
12-17-2004, 05:45 PM
Just to make sure I read your code right, whats the four jumper settings for the modes? I mean what is both off, both on, left on & right off (looking at the board from the top with the parallel port to the bottom) & finally right on & left off?

Thanks

Garfield2
12-17-2004, 06:02 PM
Just to make sure I read your code right, whats the four jumper settings for the modes? I mean what is both off, both on, left on & right off (looking at the board from the top with the parallel port to the bottom) & finally right on & left off?

Thanks

From memory it's like this :-

00 - 1/8th
01 - 1/4
10 - 1/2
11 - Full

(or it could be the reverse. you can change it easily enough while the drivers are running if you wish. It's pretty obvious which is which, hence why I cannot remember)

-A.

Garfield2
12-17-2004, 06:07 PM
Not guite 100% but nearly there....

One thing I noticed with your pictures is that you've soldered in the current setting resistors in place. Did you mean to do this?

I normally use the inner of a round pin IC-Socket so I can push the legs of the resistors into place and replace/change them easily. Unless you extremely happy with your load setting straight up that's fine to solder them in.

When I first powered up my drivers I had my motors driven with like 100mA just so I could get a feel for what the drivers where doing before I juiced them to 1.5A.

Just an idea. :)

BobLWeiss
12-17-2004, 07:27 PM
Yeah I used a breakable female header strip and just soldered 1 pin into each of the resistor holes on the pc so I could change the resistors easily down the road. I am not sure what current I want to drive the motors with either at first.

santiniuk
12-18-2004, 01:16 PM
Thanks for the feedback folks. It's certainly the incentive to keep going.

Bob I too was going to post a query on the jumper settings but you beat me too it. Let the race begin ;)

Dan's photographic tutorial is a good read, I like the writing style. Will put some of his tips into action on the next pic's.

Looks like I was caught out on the current setting resistors. I noticed this after the boards were built. Will swap these for some socket's.

I intend to try the 20 Mhz Crystals on Monday with two 27pf cap's from each leg down to gnd. Hopefully this will work. Will I need to change any config bits during the programming stage of the micro ? Not too sure on that.

I made a few notes when putting the pcb's together and marked up Alans image. On my pcb's the pads highlighted in red were almost merged into the track.There is very little clearance. The pads marked in blue are just about usable after being drilled for the connector. Maybe a bigger pad is required for home etching.

That's it I have one stepper motor to try out that has 8 wires. R.S components part number 440-470. I better see how this converts to a 4 wire device now.

Cheers,

BobLWeiss
12-18-2004, 02:18 PM
What size bit are you using for drilling? I used a 56 for most of the board and there is adequate room for soldering. I had to use a bigger bit for the ic's and screw terminals.

As for using a crystal instead of a resonator, you don't have to change anything with the code or config bits.

I am too going to be trying a 8 lead stepper.

MrBean
12-18-2004, 02:34 PM
Great progress guys. I'm going to mill my boards tomorrow (19th). I've got most of the components ready to go now. Just waiting on the resonators and a few of the caps.

I need to buy a PIC programmer as I don't have one. I was looking at these:

http://www.quasarelectronics.com/pic_programmers.htm

What do you guys think. Any of them any good or would you recommend something else.

Regards Terry.....

BobLWeiss
12-18-2004, 05:44 PM
I need to buy a PIC programmer as I don't have one. I was looking at these:

http://www.quasarelectronics.com/pic_programmers.htm

What do you guys think. Any of them any good or would you recommend something else.

I have the 3149 programmer and it I could only get it to program certain chips. I know it has something to do with programming voltage but I can't figure it out. I sent it back and got a new one and it still does the same thing. I got so pissed I just ordered the Picstart Plus from Microchip because I figure if it comes from the manufacturer of the chips it must be good. Plus you can burn right from MPLAB IDE and don't have to deal with someones third party software. I am sure the programmer works, I just found it strange I have gotten 2 units that only program like 4 different pics when it supposed to do all of them. I guess you get what you pay for.

santiniuk
12-18-2004, 06:36 PM
Cannot comment on the Quasar Programmer I'm afraid Terry but the Picstart has been fine for my use at work. I cannot claim to use it a lot but seems ok.

If your struggling to get the PIC devices I can send you three programmed ones as a swap for the resonators :) Let me know if you need them. Can post Tuesday if required.

Is there any way you can capture some video of your boards being milled ? I'm intrigued at how the milling process performs.

Bob, I cannot remember what drill size I used. It may be on the large side, or maybe just the etching quality of my boards.

Cheers

MrBean
12-18-2004, 06:48 PM
Thanks santiniuk. I may well take you up on that offer. I'm hoping the resonators will arrive monday. Will mail you when I know for sure.

I think I'll get the Picstart that you and Bob mention, at some point. (Birthday comming up). A bit pricier (£110) but sounds like it may be worth the money.

I just bought a webcam the other day for the purpose of making a video of the machine doing it's thing. It's not going to be the best quality, but should suffice.

Thanks

Regards Terry.....
http://www.terry-is.f2s.com/

Garfield2
12-18-2004, 06:58 PM
I need to buy a PIC programmer as I don't have one. I was looking at these:

http://www.quasarelectronics.com/pic_programmers.htm

What do you guys think. Any of them any good or would you recommend something else.


Well in UK speak I have one of these :-

3150 (http://www.quasarelectronics.com/3150.htm)

In Australia it's called a Kit150V2 and it comes from kitrus.com in HK. :)

It's an excellent little programmer, although don't accidently short out the VPP voltage to ground when using ICSP else you'll have to replace these tiny transistors like I had to. :(



-A.

unterhaus
12-18-2004, 07:16 PM
You can find more about the toner transfer method by going to the yahoo-group for homemade pcb's and also here:

Toner Transfer Method (http://www.fullnet.com/u/tomg/gooteepc.htm)

I am also waiting on bits to arrive so I can drill out those boards and begin contrustion of the drivers. I have most of the machine finsihed and can post pictures later on when I get the camera back..(wife...hehe)

What's the name of that group?

BobLWeiss
12-20-2004, 09:49 AM
What's the name of that group?


Homebrew_PCBs

santiniuk
12-20-2004, 11:38 AM
Things have been going too well :)

Had one of those days where things didn't go to plan.

Made the interface to Controller board IDC leads no problem.

Then made the interface lead to pc 25 pin D plug. This didn't go to plan.
I used a 26way IDC header one end (Fine) and then used a 25 pin IDC D plug the other end.
Be careful, I'm sure I'm not that daft but basically the IDC pins of the 25 pin D-plug when assembled do not match the lines of the IDC header when spliced onto the ribbon.
I had to use a standard 25 pin D-plug and solder the connections in place.
No great loss.

I then programmed the Pic with Alans latest code. Seemed to program ok and verified ok.

I then tried a 20Mhz crystal with two 22pf cap's from each lead to gnd.

I thought I would power it up at this stage and check to see what the clock looked like on the PIC. I scoped the pins but not a sign of the clock signal. The micro supply is fine.

I messed around trying the crystal without the caps but no joy.

Have other things to do now so put this to a side for a bit. Am I correct, I should see a clock signal. (I did not have the pc interface connected as I didn't have any software with me)

:(


Cheers

BobLWeiss
12-20-2004, 11:53 AM
Have other things to do now so put this to a side for a bit. Am I correct, I should see a clock signal. (I did not have the pc interface connected as I didn't have any software with me)

:(


Cheers


Yes, you should have gotten a signal on one of the crystal leads...20mhz clock signal so you know its running. Something has to be off...it has nothing to do with the computer connection either. First get the PIC running, make sure gound and power are good +5vdc, and that one end of each cap is grounded, the other end to each lead of the crystal. Make sure the crystal is connected to the OSC pins 1 & 2 on the PIC also. Since you changed it from being a resonator are you still using his mounting holes in the circuit board?

santiniuk
12-20-2004, 12:05 PM
Bob,

Had a clean 5V supply to micro across pin 5-14. I mounted the crystal in the same pads as the resonator. Used the outer holes for the crystal leads and then from each crystal lead to the center pad (gnd).

I was checking pins 15 & 16 of the pic for a clock signal.

Thanks

BobLWeiss
12-20-2004, 12:07 PM
When you say you put the leads from the crystal to the center hole (gnd) did you go through a cap from each lead first then to gnd? In other words, the crystal leads are not grounded themselves right? They must go to one end of each cap, then the cap's other leads are grounded.

Bob

santiniuk
12-20-2004, 12:23 PM
Yes,

Sorry didnt clarify. One cap lead to gnd the other to a Xtal lead. both sides.

Config bits programmed as per attached image of micro.

Ok ?

BobLWeiss
12-20-2004, 12:35 PM
NO, I see your problem. You have the oscillator bits set to IO mode. They must be set to _HS_OSC. Hi frequency Oscillator mode.

I just checked his code (newer version and I think he changed it and its wrong I beleive)

Garfield2
12-20-2004, 03:37 PM
Yes, you should have gotten a signal on one of the crystal leads...20mhz clock signal so you know its running. Something has to be off...it has nothing to do with the computer connection either. First get the PIC running, make sure gound and power are good +5vdc, and that one end of each cap is grounded, the other end to each lead of the crystal. Make sure the crystal is connected to the OSC pins 1 & 2 on the PIC also. Since you changed it from being a resonator are you still using his mounting holes in the circuit board?

I've never been able to see a OSC pulse on the OSC1 and OSC2 pins. You need really low capacitance probes etc. Whenever I've touched the OSC pins with anything the oscillation stops instantly, it's very fussy!

I can verify what Bob has found. I've uploaded a 4MHz version of the code instead of the 20MHz. With this version the boards can be used without a crystal/resonator. I'll upload the 20MHz version now.

Sorry!

Alan.

BobLWeiss
12-20-2004, 03:42 PM
I've never been able to see a OSC pulse on the OSC1 and OSC2 pins. You need really low capacitance probes etc. Whenever I've touched the OSC pins with anything the oscillation stops instantly, it's very fussy!

I use a good probe with my scope and can see a nice sin wave output on the screen usually. That's how I can tell if my chips are running at all..First debug mode when working with PIC's, otherwise I'm in the dark.

ViperTX
12-20-2004, 04:12 PM
Yes,

Sorry didnt clarify. One cap lead to gnd the other to a Xtal lead. both sides.

Config bits programmed as per attached image of micro.

Ok ?
For grins pull the reset line on the processor with VCC on. I'm wondering if you have a power on reset problem....don't know what your circuit looks like...

Garfield2
12-20-2004, 04:17 PM
For grins pull the reset line on the processor with VCC on. I'm wondering if you have a power on reset problem....don't know what your circuit looks like...

MCLR is internally pulled high and the MCLR line is being used as an input.

What is the problem you're seeing?

Alan.

Garfield2
12-20-2004, 04:19 PM
I use a good probe with my scope and can see a nice sin wave output on the screen usually. That's how I can tell if my chips are running at all..First debug mode when working with PIC's, otherwise I'm in the dark.

Not everyone has a "nice" scope.. :P

:)

Alan.

Garfield2
12-20-2004, 04:23 PM
Things have been going too well :)

Had one of those days where things didn't go to plan.

Made the interface to Controller board IDC leads no problem.

Then made the interface lead to pc 25 pin D plug. This didn't go to plan.
I used a 26way IDC header one end (Fine) and then used a 25 pin IDC D plug the other end.
Be careful, I'm sure I'm not that daft but basically the IDC pins of the 25 pin D-plug when assembled do not match the lines of the IDC header when spliced onto the ribbon.
I had to use a standard 25 pin D-plug and solder the connections in place.
No great loss.



Keh! They're suppose to line up exactly..!?! That was the whole idea of the IDC.

Your 25pin D plug should accept a 26 way cable. The 26th pin is dormant.






I then programmed the Pic with Alans latest code. Seemed to program ok and verified ok.

I then tried a 20Mhz crystal with two 22pf cap's from each lead to gnd.

I thought I would power it up at this stage and check to see what the clock looked like on the PIC. I scoped the pins but not a sign of the clock signal. The micro supply is fine.

I messed around trying the crystal without the caps but no joy.

Have other things to do now so put this to a side for a bit. Am I correct, I should see a clock signal. (I did not have the pc interface connected as I didn't have any software with me)


Yeah that's my fault. You've got the internal oscillator version. I'd mistakenly uploaded a 4MHz version I was testing, so the HS oscillator is turned off!

Sorry,
Alan.

santiniuk
12-20-2004, 04:51 PM
Bob, Many thanks again. I totally missed the oscilllator error. It was just one of those days :) Alan, thanks for the speedy fix !

It's not wise trying to rush things during a lunch worktime .......

Well I guess other's may have stumbled on this too so at least some good from my misfortune.

So tomorrow is a fresh start. Fingers crossed.

ViperTX the details are on Alans website :- http://www.fromorbit.com/projects/picstep/

Alan, If I use the 4Mhz code I can remove the resonator or Xtal and caps in my case ?

I presume the 20Mhz code requires an external Resonator or Xtal / cap config ?

Is there any major disadvantages to the 4Mhz code ?

Finally I won't make any excuse it was a rough weekend. ;) I will review my IDC lead tomorrow at work. I must have missed something. (Plonker!)

Cheers all ....

santiniuk
12-21-2004, 08:48 AM
Alan,

Downloaded the latest files you have uploaded.

It appears that inside the zip file there are two set's of code.

At root level the .asm code is declaring

TITLE "PICStep V1.01"

LIST R=DEC
INCLUDE "p16f628a.inc"

__CONFIG _CP_OFF & _WDT_ON & _INTOSC_OSC_NOCLKOUT & _PWRTE_ON & _LVP_OFF & _BOREN_ON & _MCLRE_OFF

There is a folder called home that also contains code. The .asm file in this calls for :-

TITLE "PICStep V1.01"

LIST R=DEC
INCLUDE "p16f628a.inc"

__CONFIG _CP_OFF & _WDT_ON & _HS_OSC & _PWRTE_ON & _LVP_OFF & _BOREN_ON & _MCLRE_OFF

This is for the 4Mhz and 20Mhz code.

santiniuk
12-21-2004, 08:53 AM
New code...

20Mhz Crystal and 22pf cap's

I have a clock......

Also sorted the IDC problem. Stupidly I was trying to match the IDC header pins to the 25 Pin D Plug. i.e 1-1 2-2 3-3 4-4 etc....

BobLWeiss
12-21-2004, 08:59 AM
So what's the verdict? Are you controlling the stepper motor yet? How's it working out? I just got the rest of my parts last night and put together the board. I have to run out today and get some wire for my power supply so I can test it all out tonight. Anxious to hear how it works..

Garfield2
12-21-2004, 04:00 PM
Alan,

Downloaded the latest files you have uploaded.

It appears that inside the zip file there are two set's of code.

At root level the .asm code is declaring

TITLE "PICStep V1.01"

LIST R=DEC
INCLUDE "p16f628a.inc"

__CONFIG _CP_OFF & _WDT_ON & _INTOSC_OSC_NOCLKOUT & _PWRTE_ON & _LVP_OFF & _BOREN_ON & _MCLRE_OFF

There is a folder called home that also contains code. The .asm file in this calls for :-

TITLE "PICStep V1.01"

LIST R=DEC
INCLUDE "p16f628a.inc"

__CONFIG _CP_OFF & _WDT_ON & _HS_OSC & _PWRTE_ON & _LVP_OFF & _BOREN_ON & _MCLRE_OFF

This is for the 4Mhz and 20Mhz code.

DAMN IT! I'm so busy at the moment I keep stuffin things up.. Sorry.

I'll update it later today, I must have zip'd it in my home dir and I didn't delete the old code first! Or I did something daft like I accidently appended the new files to an old zip file.. (probably that last one)

Will fix.

Alan.

Garfield2
12-21-2004, 04:04 PM
New code...

20Mhz Crystal and 22pf cap's

I have a clock......


Cool.. what software/hardware you using to do that? I've got like a 1972 BWD dual trace 20MHz CRO, but I'd love a PC based DSO. What is it! :)



Also sorted the IDC problem. Stupidly I was trying to match the IDC header pins to the 25 Pin D Plug. i.e 1-1 2-2 3-3 4-4 etc....

Excellent.. Thought I wasn't stupid lat time I checked... :)

It should go 1-1, 2-3, 4-5, 5-7 etc etc for the top and 14-2,15-4,16-6 yadda yadda for the bottom

Alan.

santiniuk
12-21-2004, 05:59 PM
A brief post.

:)

It's alive !

Just connected to turbocnc and all axis are working.

Played with the jumpers and tried the various step modes. All work.

Time for a tidy up and review what software to go for.

Alan, many thanks for sharing this. Quite amazing that we are at opposite ends of the earth. (The scope is one I use at work. Tektronix TDS5000 series. Some hideous price. £10k when we purchased it. - I barely scratch the surface with what it can do)

Bob, appreciate all of the support on this. :cheers:

Hopefully grab some images shortly.

Terry I can sort your pics out now I am confident I programmed the pics with the right code.

Garfield2
12-21-2004, 06:12 PM
A brief post.

:)

It's alive !

Just connected to turbocnc and all axis are working.

Played with the jumpers and tried the various step modes. All work.

Time for a tidy up and review what software to go for.


Excellent, now lets see if the dreaded CNC motor controller curse doesn't grip you! It's the one where once you see motors spinning via software control, you never actually build the machine. It's amazing how many people stop with CNC once they see motors spinning under computer control. :)

Hope you push on through!



Alan, many thanks for sharing this. Quite amazing that we are at opposite ends of the earth. (The scope is one I use at work. Tektronix TDS5000 series. Some hideous price. £10k when we purchased it. - I barely scratch the surface with what it can do)

Many thanks. Well if anyone feels super generous, I'd very graciously accept a Tektronix anything.. :)

Well done.

Cheers,
Alan.

BobLWeiss
12-21-2004, 06:24 PM
Bob, appreciate all of the support on this. :cheers:

Hopefully grab some images shortly.

No problem...I want to thank Alan as well...great work!

I am working on mine now and hopefully get the motors spinning tonight. My machine is built, it just needed a driver so I might be actually cutting something soon!!!

Can't wait to see pictures...I will post some as well

Bob

BobLWeiss
12-21-2004, 09:05 PM
I got mine to work...well sort of. I only have 1 axis built and the breakout board and I'm running TurboCNC in DOS mode. I tried to jog the motor using F8 and the arrow keys and the Y axis controlling the first IDC header. (It is set as using pin 2 as step and 3 as direction by default) and the arrow key is moving the motor nicely in both directions...

I tried to configure the program so that X was using pin 4 as step and 7 as direction and it doesn't do anything on any of the headers...Strange problem. So the only header working is the first one and just the Y arrows let it move. I am thinking its my parallel cable (which I did not build, I got it out of an old PC that had and IDC header on the motherboard and the 25pin female port on the other.) I have to figure this problem out and then I'm ready to role.


EDITED: I made a cable using what Alan recommends, IDC 26 pin header and a 25pin IDC DB25 connector and it still does the same thing. Only the y axis arrow works and nothing else. The motor is running great in all 4 modes so it can't be the controller board, it has to be something with either the computer port, breakout board or TurboCNC setup.

What are your setup parameters for TurboCNC for the 3 axis's? What pins are you using for X, Y & Z step and direction? Active Low right? Linear mode and what is your step pulse 10?

Thanks,
Bob

santiniuk
12-22-2004, 04:48 AM
Bob,

My turbocnc.ini file is attached. I didn't change anything from the default install for it to work on all headers.

Good luck.

BobLWeiss
12-22-2004, 07:19 AM
DUH!! I think I found my problem. I was going by the schematic on his site which has the pins from the 26 IDC connector going to each of the axis connectors labeled wrong. When I looked at the actual board layout and I see that X is pins 2 & 3, Y is 4 & 5 and Z is 6 & 7. I should have no problem now..I have to put TurboCNC's setup back to the default.

Thanks for the ini file, I will be using that instead of messing anymore with the software. Now I have to finish the other 2 boards tonight and I can begin to cut something...This has been a 2 month project so far and loving every minute of it...

How far away are you from a competed machine? Did you start building yet?

Bob

santiniuk
12-22-2004, 08:56 AM
Well that's it. Finished work now and return on the 4th Jan.

Bob,

All I did was download Turbocnc v4.0 from the website. I have not installed any Hotfix.
I'll explain my setup.

* I changed no settings in turbocnc. I am using an old laptop with 98 / dos on. (I didn't want to kill my good laptop!)

* I run turbocnc in dos mode.

* Now I have had chance to play with it this is what turbocnc operates from a clean install.

* I did make the breakout/pc interface board too.

Using the jog keys:-

X axis controls Conn2
Y axis controls Conn1
Z axis controls Conn3

I have not used Conn4

So basically if I use the jog keys all motors are controlled correctly. Using the alt-Jog key makes a fast jog which works fine.

The default turbocnc settings seem to use pins :-

xstep 4
xdir 5

Ystep 2
ydir 3

zstep 6
zdir 7

step pins defined as active Hi
direction pins defined as Hi

motion Linear
Drive Type Step/Dir
pulse width 10

I hope this helps. I'm afraid it just worked.

I do have a query. All of the switch inputs work fine. They work in software and I can see them work. But one connector S2 when closed puts a brief pulse out onto the motors. This doesn't sound right ?

Cheers,

Time for a beer !

BobLWeiss
12-22-2004, 10:42 AM
I do have a query. All of the switch inputs work fine. They work in software and I can see them work. But one connector S2 when closed puts a brief pulse out onto the motors. This doesn't sound right ?

Cheers,

Time for a beer !

Yeah I hear ya on that one... :cheers:

I will check that out tonight with the switch...I have limit switches setup on my machine and gonna run wire to them and use the switch connectors on the breakout board to tell TurboCNC that it reached the limits.. I did play around with the Alt-jog keys too and I like the movement it has..very smooth. What mode are you planning on running in once your setup? I think I might stick with the Full-step mode..seems to be good enough for what I'm going to be using it for...What voltage is your powersupply?

Garfield2
12-22-2004, 05:14 PM
I think I might stick with the Full-step mode..seems to be good enough for what I'm going to be using it for...What voltage is your powersupply?

Full step mode doesn't give you any of the advantages of a microstepping controller! It's basically becomes a chopped full step controller. Microstepping only happens when you use the other modes (1/2,1/4,1/8). I was playing with the idea of making the full step mode actually a burst of 8 x 1/8 steps so you get the advantage of the microstepping motor control and a full step operation.

I'd recommend you use 1/4 for most things, and just set up TurboCNC with a 1/4 step adjustment in the motor settings. The smoothness will be worth the extra alignment time.

Cheers,
Alan.


PS PICTURES PLEASE I wanna put some more photos of people's boards/setups on my site!!

Garfield2
12-22-2004, 05:18 PM
DUH!! I think I found my problem. I was going by the schematic on his site which has the pins from the 26 IDC connector going to each of the axis connectors labeled wrong.

Ahem! NOT LABELED WRONG.. :P

READ WRONG.. :)

26 way IDC != DB25 pinout (chair)

Cheers,
Alan.

Garfield2
12-22-2004, 05:31 PM
I hope this helps. I'm afraid it just worked.

Glad to hear that!




I do have a query. All of the switch inputs work fine. They work in software and I can see them work. But one connector S2 when closed puts a brief pulse out onto the motors. This doesn't sound right ?


The S2 thing sounds like a software glitch or something, there should be no electronic reason for it since it's just grounding a parallel port pin. Unless you've got a really long cable and it's inducing interference in the port (guessing here). I've not seen such a problem here.

I am attempting to build an opto-isolated breakout board soon, that is compatible with PICStep and PICServo (once I complete the new firmware). I've attached a photo of my PICServo testbed... it's getting there.

Cheers,
Alan.

santiniuk
12-22-2004, 06:38 PM
Alan, Sorry no pics so far. Been to a panto with the kids tonight.

He's behind you.......... ;)

I am very interested in the Opto-Isolated interface. Would prefer the isolation on my 'good' laptop.

Bob, your miles ahead of me. I need to start from scratch with the mechanical stuff.
I cannot complain. Time has not been good lately but seeing the controllers running is a good incentive. (I really hope I don't fall into the trap Alan mentioned)

At this stage I'm using a 12V 20A supply I had laying around. The motors are only 12V 0.6A for testing things.

Cheers.

BobLWeiss
12-22-2004, 08:40 PM
Here are 2 pictures of my completed Y and Z drivers. I made them on 1 piece of copper.

Bob

http://www.boblweiss.com/Completed_YZ.jpg

http://www.boblweiss.com/Completed_YZ2.jpg

santiniuk
12-23-2004, 11:42 AM
Bob,

I like the idea of two axis on one pcb. Did you manage to see any life from your machine ? I was hoping to see some pic's of it in action. That will really spur me on...
I have a friend who is dropping hints that he would like to join me on my project. If so I may try and use Alan's original design but combine 3 axis on one pcb. I don't have a need for the ICP feature so may miss this out and maybe combine the power lines etc.

Overall really enjoyed this construction. Even that damn IDC mistake. Alan's code error had me going mad. Surely even I can get a clock working :)

My wife asked me if I wanted to go shopping today or would I prefer to look after the kids. It was a hard choice but at least looking after kids allowed me a bit of time.

So... Mounted the boards on some MDF and tidied things up a bit. Pictures attached. The motors are 8 wire one's I used for testing only. Only 12V 0.6A devices so wiring is on the light side. Will butch it up when I get to the next stages. The heatsinks are just bits I had around and roughly cut to size.

Again thanks to all who contributed. I wish you and your families a Merry Christmas and a Happy New Year !

Cheers,

Shaun

BobLWeiss
12-23-2004, 11:55 AM
They look good. First, and most important, Merry Christmas to you and yours also!!! :)

I am only working 1/2 day today so I can go home and play a little too... :cheers:

I got all the axis working last night (my mistake), and all I have left is to wire up the limit switches and spindle power and call it complete. I have to stop at the store today and pick up wire, my motors are also 8 wire and the leads are not long enough to reach the box I have everything in. So I will be doing some wiring tonight. Can't wait to see it all in action...I will take pictures.

Garfield2
12-23-2004, 04:13 PM
I like the idea of two axis on one pcb. Did you manage to see any life from your machine ? I was hoping to see some pic's of it in action. That will really spur me on...
I have a friend who is dropping hints that he would like to join me on my project. If so I may try and use Alan's original design but combine 3 axis on one pcb. I don't have a need for the ICP feature so may miss this out and maybe combine the power lines etc.


My original design had all axis on the one PCB. I opted to make them seperate incase I ever damaged one I could easily replace a module, and not risk the entire board. These are motor drivers so sometimes things can go mightly wrong! :)



So... Mounted the boards on some MDF and tidied things up a bit. Pictures attached. The motors are 8 wire one's I used for testing only. Only 12V 0.6A devices so wiring is on the light side. Will butch it up when I get to the next stages. The heatsinks are just bits I had around and roughly cut to size.


Looks excellent. Well done. Although it looks like you're missing the 1uF MKT's that bypass the LMD's from your photos. If you haven't already you might want to reconsider putting them in place as they stop high frequency back-EMF killing the MOSFETs. The datasheet for the LMD's where quite specific that an electro and a ceramic/MKT are needed to bypass the supply. It'll probably work just fine without it, but when you start cranking the amps and the motors are spinning at high RPM I'd rather have them on mine than not! :)



Again thanks to all who contributed. I wish you and your families a Merry Christmas and a Happy New Year !


Merry Xmas to you too.. I'll race you to who gets to unwrap presents first :P

(GMT +10 hours) hehehe

Cheers,
Alan.

santiniuk
12-23-2004, 08:31 PM
I Don't believe it !

The .1uF Caps I ordered are the wrong pitch. I remember thinking, ahh big electrolytic there in parallel, will probably work for testing but must get the right ones !

It seems I have a dislike for .1uF as it's missing from the interface psu too.

Thanks for reminding me on that one Alan, must get them in before any real action.

Not that there will be much for a while .....

I joined Terry and 'virutally' milled one of your board tonight. I need to get out more ;)

Thanks

BobLWeiss
12-23-2004, 08:51 PM
Yeah I would make sure you have it installed before you do any actual motor spinning. What's your next step? Do you have any hardware for your machine yet or still in the planning stages? What's your design like?

I got my boards all wired up in the case with the power supply. I am wiring up the limit switches now.

Let me ask this, what is better if your motors can produce enough torque in either configuration (series and parallel), what are the benefits to running the motors (6 & 8 lead) in one way or the other? For testing I just wired them up using just the top half of the phases and left the bottom halves disconnected. Would one way give more speed or it doesn't matter...

Thanks!

MrBean
12-23-2004, 09:02 PM
Yeah I would make sure you have it installed before you do any actual motor spinning. What's your next step? Do you have any hardware for your machine yet or still in the planning stages? What's your design like?

I got my boards all wired up in the case with the power supply. I am wiring up the limit switches now.

Let me ask this, what is better if your motors can produce enough torque in either configuration (series and parallel), what are the benefits to running the motors (6 & 8 lead) in one way or the other? For testing I just wired them up using just the top half of the phases and left the bottom halves disconnected. Would one way give more speed or it doesn't matter...

Thanks!

To run either, series or parallel, you'll use all 8 wires. What you choose depends on your motor specs and power supply. Parallel will use double the Amps of series = more torque.

Regards Terry.....

BobLWeiss
12-23-2004, 09:19 PM
To run either, series or parallel, you'll use all 8 wires. What you choose depends on your motor specs and power supply. Parallel will use double the Amps of series = more torque.

Regards Terry.....

Well you could use just the top half of each phase and totally ignore the bottom half (4 wires total) correct? What I would like to know though is besides torque, is their any other benefit to wiring it either series or parallel? Is there any wiring combination that increases speed? My power supply is 42vdc, 16amps (able to source). The motors are NEMA 23's, 1.1v, 1amp per phase.

Bob

MrBean
12-23-2004, 09:41 PM
If you use only 4 wires, that is niether series or parallel. Voltage = speed so Series would give you more speed at half the torque of parallel. Amps = torque so parallel gives more torque at half the speed of series. I think thats more or less how it goes. If that mokes sense to you.

Regards Terry.....

BobLWeiss
12-24-2004, 02:26 PM
I finally completed the drivers and power supply. I also made a circuit board last night to give me 12vdc for my spindle motor and also have a relay for operating it. I secured it all in an old PC case and its ready to start cutting. The specs came out as 53vdc, 15 amp PS, 3 PicStep (http://www.fromorbit.com/projects/picstep/) drivers, and a 12vdc regulator for accesories.

http://www.boblweiss.com/images/Complete_Driver.jpg

santiniuk
12-24-2004, 06:21 PM
Looking good Bob !

I guess you must be really close to cutting now if you have not done so already.

I'm not sure if you have posted any details of your hardware so keep the updates coming.

Are you using Turbocnc or something else ?

(I now need to focus on the hardware side so look forward to some guidance as usual....)

Cheer's

BobLWeiss
12-24-2004, 06:58 PM
I guess you must be really close to cutting now if you have not done so already.

I still have a few things to finish on the machine side and also finsih running the wiring for the motors. I bought some wire loom to hide all those wires and make it nice and tidy.


I'm not sure if you have posted any details of your hardware so keep the updates coming.

I will take some pictures of the machine and post them soon. It mostly made of MDF and drawer slides. I bought 2 lead screws for X & Y from here. (http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM94MEC2601&Category_Code=MEC) and the Z axis was made for me with spindle.

I am using TurboCNC for now until I decide which program I want to stick with. I want to try Mach2 as well.

I don't have anything to cut right away and was looking online for something cool to cut out of wood to give it a test run. Does anyone know of any sites that have Gcode of wooden projects ready to cut?

Bob

santiniuk
12-26-2004, 05:56 AM
Well Santa has been and the kids are finally starting to calm down !

Hope you all had a good day.

Time to sit back now and plan the next stages. Quite amazing some of the creations on this forum.

I'm trying out some of the trial downloads for software at the moment. I prefer the windows evironment but I understand you have to watch out for timing issues etc.

Waiting eagerly to see your posts Bob.

Thanks

ger21
12-26-2004, 08:16 AM
What I would like to know though is besides torque, is their any other benefit to wiring it either series or parallel? Is there any wiring combination that increases speed?
Bob


Typically, when wired in series, you'll get full torque from the motor at low speeds, but torque will drop off very fast as rpm's increase. When wired parallel, you might get a litlle less low speed torque, but you'll have much more torque at higher speeds, which will usually allow faster motion on your machine. generally, parallel is the way to go if you can supply enough current to wire them that way.

BobLWeiss
12-26-2004, 08:43 AM
Typically, when wired in series, you'll get full torque from the motor at low speeds, but torque will drop off very fast as rpm's increase. When wired parallel, you might get a litlle less low speed torque, but you'll have much more torque at higher speeds, which will usually allow faster motion on your machine. generally, parallel is the way to go if you can supply enough current to wire them that way.

Thanks for the input, which leads me to another question, I also have a 6 wire motor, if power supply is able to provide enough power for whatever arrangement, would you wire that motor using the whole coil per phase (ignoring the center tap) or just use 1/2 the coil and ignore the bottom end of each coil? (Remember, I am going for max speed since torque is not an issue)

@santiniuk

Glad to hear you had a good day yesterday, I did as well. Kids loved it!!

Now today is Dad's day to play, back to the machine. I will take some pictures today for you. I am going to be test running it this afternoon. I found some Gcode's of a clock gear to test cut with. Crossing my fingers.... :rolleyes:

ger21
12-26-2004, 10:52 AM
I believe that with 6 wire motors, 1/2 coil gives the best speed. Not 100% sure, though.

MrBean
12-26-2004, 08:08 PM
Hi guy's. Nice to hear you all had a good time over Christmas.
I've finished my first PICStep board, made on the CNC router. Looks ok, but I can't test it as I have no PIC's yet. Could this be the only milled PICStep in existance??

If only I could get the machine to do the soldering...........Maybe one for the future.

Anyway, here's some pictures.

santiniuk
12-26-2004, 08:21 PM
Wahay, that is so impressive ! Well done.

It really must be rewarding knowing you actually built the machine that milled the board. It's a shame about the pic's. If you manage to get them the offer still stands on the programming. I'm really interested to see how much of an improvement these boards are over your old ones. I don't have anything to compare against or a machine built :)

That I.C socket looks so lonely too ;)

Thanks for the update.

MrBean
12-26-2004, 08:37 PM
santiniuk. Thanks for the offer. I think I'll take the plunge once we're into the new year and buy a programmer. I'll need one for some other projects soon anyway.
Toner transfer would've been easier, but I wanted to make these using the router. I learned a lot doing it this way and as I get more experience, milling boards should be quicker, especially with some decent drivers. I'll let you know how much difference these make over the ol' crappo ones, once they're running and I've done some testing.

Regards Terry.....
http://www.terry-is.f2s.com

BobLWeiss
12-26-2004, 09:15 PM
Mr Bean: Did you use Eagle to generate the Gcodes for it? If so which ULP did you run to get the output? Was the output ready to run in TurboCNC or did you need to do more steps in between? If you didn't use TurboCNC then which program do you use? I would love to try it out on my machine to test the accuracy. Which type and size bit did you use? Sorry for all the questions...just learning this stuff myself.

Thanks,
Bob

By the way, great job!! Looks real good. :cheers:

MrBean
12-27-2004, 06:15 AM
Mr Bean: Did you use Eagle to generate the Gcodes for it? If so which ULP did you run to get the output? Was the output ready to run in TurboCNC or did you need to do more steps in between? If you didn't use TurboCNC then which program do you use? I would love to try it out on my machine to test the accuracy. Which type and size bit did you use? Sorry for all the questions...just learning this stuff myself.

Thanks,
Bob

By the way, great job!! Looks real good. :cheers:



Hi Bob. I did'nt use Eagle or the ULP scripts. There was quite alot of manual work to do. I took the original artwork (EPS) and converted to a raster image. I then manually drew between the tracks to make an isolation "patchwork" rather than tracks. I then deleted the tracks to leave the patchwork lines, saved this as a GIF. I then converted the patchwork back to vector (DXF). I have a few ideas to speed this process up, but I don't have time to try them yet. Using this approach you can lift trace artwork from magazines etc..and convert them for isolation milling.

I used Mach2 to import the DXF and create the G-code. I manually added a few G commands (exact stop mode and inch units.) I also edited the rapid Z height moves in the code as by default it wanted to make all G00 moves 1" above the board. Mach2 was used to run the G-Code. Mach2 is great.

I made my own cutter in the end. All the bought ones I tried were crap, and I tried quite a few. On my website there's a picture of one of the cutters I bought. I ground the end of that cutter to a sharp pointy cone and then ground half of the cone away at the side, to leave one flat side. I used that to cut the boards, cleaned them up with some wet & dry and finished with wire wool.

I'll put the G-code and DXF's for the isolation path and drill path on my website ( http://www.terry-is.f2s.com ), sometime today. So you can try them out. Two holes on the drill file are missing. They are for the link wire that goes between the LMD18245's, right next to the 10nf MKT Cap. There are also two extra holes in opposite corners of the board, they are on the rectangle that surrounds the entire board and were used as reference points so that the two G-Codes line up exactly. If you try it let us know how it goes.

Regards Terry.....
http://www.terry-is.f2s.com

BobLWeiss
12-27-2004, 08:06 PM
Well I had a setback today. I burned up 2 of my controller boards, actually the LMD18245's. I was hooking everything up and testing each axis in turn and all of a sudden one of the driver chips popped! Then a second one. Well I don't know what actually caused this since I had them running before fine, I am thinking that my power supply is too big for it. The power supply I used the first time was 24vdc and the one I just hooked up is the one I built that was outputting 53vdc without a load. I know the chips are rated to 55vdc but I can't seem to figure what else it could have been. I did notice that the chips popped on the Voltage In pin (9) and melted it. Thank God I have a few more chips left over, I am desoldering them now and gonna replace them and try it all again but with the 24vdc supply. If it works fine with that one than I am just gonna use that instead of the toridal transformer one. What's another couple days.... stay tuned.

ViperTX
12-27-2004, 08:46 PM
Well I had a setback today. I burned up 2 of my controller boards, actually the LMD18245's. I was hooking everything up and testing each axis in turn and all of a sudden one of the driver chips popped! Then a second one. Well I don't know what actually caused this since I had them running before fine, I am thinking that my power supply is too big for it. The power supply I used the first time was 24vdc and the one I just hooked up is the one I built that was outputting 53vdc without a load. I know the chips are rated to 55vdc but I can't seem to figure what else it could have been. I did notice that the chips popped on the Voltage In pin (9) and melted it. Thank God I have a few more chips left over, I am desoldering them now and gonna replace them and try it all again but with the 24vdc supply. If it works fine with that one than I am just gonna use that instead of the toridal transformer one. What's another couple days.... stay tuned.
I suspect that this circuit uses 2 of the LMD's to drive 2 phases on one stepper, if that is the case then I suspect that one phase encountered an overload condition, it appears from the data sheet that over 30 vdc the built-in current limiting might not work.

The problem with these chips is that the inputs must be closely synchronized otherwise it's very easy to get the timing off a bit and you end up with catastropic results....I bet the circuit design is not robust enough...just a thought... (chair)

MrBean
12-27-2004, 08:46 PM
That's a real bummer. Those LMD's aren't cheap. I hope you get it sorted soon, we're all itching to hear how they perform on the machine. Fingers are crossed for you Bob.

Regards Terry.....

santiniuk
12-28-2004, 05:33 AM
Oh Nightmare. I know the LMD's are not cheap in the UK. Hope they are not too bad in the U.S.

I stumbled across a site a few days ago which had a neat design too for a microstep controller.

The address is http://www.embeddedtronics.com/

Click the microstep link.

It's interesting that they state on there site :-


We have tested the LMD18245 driver chips continuously with a 44volt power supply. Although the driver chip can handle 55volts, there should be some safety margin for stepper motor induced back EMF voltage. We recommend no more than a 44volt supply for reliable and trouble free operation.


Let's hope this is not too much of a setback for you Bob. How did you have the phases of the stepper's wired ? I'm keen not to repeat this burnout !

Cheers

BobLWeiss
12-28-2004, 08:22 AM
Well the good news is that I got the chips sent to me as samples so they didn't cost anything. :)

I am in the process of making 2 new boards today and have to wait for the capacitors to come in since I only ordered enough last time to make the 3 boards. No big deal, cost is only about $5 total for everything that I need, its just the pain in the neck of having to redo 2 boards and hand drill them, and the worst part is making the wire bridges. This time I am leaving out the in circuit programming connector and the dip switches and just going to use wire to bridge those 4 gaps. I use a socket on the PIC anyway, so I can just take it out and reburn it if needed in the future. I also have my machine all ready to go now, all limit and home switches are wired and motors are wired with extended lengths and I used cable looms to make it all look pretty. I am going to use the 24vdc supply when I am ready, it has 3 outputs of 2A each and my motors are rated at 1 to 1.1 amps a phase so this should be good enough. Not sure on what speed I will end up with but I can deal with that since this machine is for me as a hobby and I am not using it for any type of production stuff. If it takes 30minutes to cut something so be it.

I guess using that much power was a bad thing...I know I wired the motors right, so I wouldn't worry about anyone here making the same mistake.

MrBean
12-28-2004, 07:03 PM
How's it comming along Bob. I've milled up the interface board. (See pictures). I won't be making much progress now for a week or two. I need to get the PIC's, a programmer and some female IDC connectors, as I ordered the wrong ones. (chair)

Have a good new year all.


Regards Terry.....
http://www.terry-is.f2s.com

BobLWeiss
12-28-2004, 07:49 PM
You have a great new year as well. I am etching my 2 boards now as I type this. I will drill them out tomorrow and begin rebuilding them. Should be back in business by Friday I hope...

santiniuk
12-28-2004, 09:02 PM
Terry the interface board looks like your best work so far. The tracks are so defined. Well impressed.
After you mill the boards do you have to do much 'tidying up' or is the board like the picture you posted ?

Good luck with the boards Bob, I have sympathy with you. The drilling seemed never ending..... And those damned wire links.....

The demo of Mach2 looks impressive. If I get the next stages done I may go for it.

Cheers

MrBean
12-29-2004, 04:48 AM
Terry the interface board looks like your best work so far. The tracks are so defined. Well impressed.
After you mill the boards do you have to do much 'tidying up' or is the board like the picture you posted ?
Cheers


I reground the end of my homemade cutter for this board and it came out much better. (still a lot of trial end error going on).
The channel edges are left with some very small burrs but 5 seconds or so with some 400 grit paper removes those, then I polish it off with a quick rub of fine wire wool and brush the debris out with a stiff brush.

I'm really glad I don't have to drill all those holes by hand.

Regards Terry.....

Garfield2
12-29-2004, 11:20 PM
I bet the circuit design is not robust enough...just a thought... (chair)


Errmmm I take offense to that!

Alan.

Garfield2
12-29-2004, 11:25 PM
Well I had a setback today. I burned up 2 of my controller boards, actually the LMD18245's. I was hooking everything up and testing each axis in turn and all of a sudden one of the driver chips popped! Then a second one. Well I don't know what actually caused this since I had them running before fine, I am thinking that my power supply is too big for it. The power supply I used the first time was 24vdc and the one I just hooked up is the one I built that was outputting 53vdc without a load. I know the chips are rated to 55vdc but I can't seem to figure what else it could have been. I did notice that the chips popped on the Voltage In pin (9) and melted it. Thank God I have a few more chips left over, I am desoldering them now and gonna replace them and try it all again but with the 24vdc supply. If it works fine with that one than I am just gonna use that instead of the toridal transformer one. What's another couple days.... stay tuned.

Bob, bummer about the blow out, but you were pushing the upper limits of the controllers. Nearing 55VDC I suggest going across the LMD's datasheet and verifying their needs at that voltage, I've mentioned this in previous conversation. I've only had the controllers up to 40VDC (haven't needed any higher as the motors RPM was more than usable) so you've entered "god country" going above that. :)

Hope all is well anyhow. It's all a learning experience.

Alan.

Garfield2
12-29-2004, 11:28 PM
Hi guy's. Nice to hear you all had a good time over Christmas.
I've finished my first PICStep board, made on the CNC router. Looks ok, but I can't test it as I have no PIC's yet. Could this be the only milled PICStep in existance??

If only I could get the machine to do the soldering...........Maybe one for the future.

Anyway, here's some pictures.


Nice work! I'll post these on my website once I return home.

Alan.

Garfield2
12-29-2004, 11:32 PM
The address is http://www.embeddedtronics.com/

Click the microstep link.

It's interesting that they state on there site :-


Let's hope this is not too much of a setback for you Bob. How did you have the phases of the stepper's wired ? I'm keen not to repeat this burnout !


Indeed, it's good advice! Read the spec sheets for the LMD's if you are going to approach their upper limits! I cannot stress this enough! I don't want people faulting the design when it's not at fault!

I've not used PICStep above 40VDC because I've had no need to, this isn't a commercial product and I don't have the resources to test things to destruction, so if you deviate from my design/groundwork I cannot help! :)

Cheers,
Alan.

Garfield2
12-29-2004, 11:37 PM
The drilling seemed never ending..... And those damned wire links.....

The curse of the single layer board.. Heck, you could be saying :


I can never seem to get the holes to line up... those damn layers!... Plus soldering in short pieces of wire in the vias is such a pain, man I wish I had a hole plating machine!


:P

:)

Cheers,
Alan.

BobLWeiss
12-30-2004, 07:05 AM
Indeed, it's good advice! Read the spec sheets for the LMD's if you are going to approach their upper limits! I cannot stress this enough! I don't want people faulting the design when it's not at fault!

I've not used PICStep above 40VDC because I've had no need to, this isn't a commercial product and I don't have the resources to test things to destruction, so if you deviate from my design/groundwork I cannot help! :)

Cheers,
Alan.

I know I tried pushing the limits and thanks to me, you guys are spared the agony of rebuilding. :rolleyes:

Its not a big deal really...I had more chips to use so no loss. I still think your design is the best one yet and I am almost finished rebuilding it. I am just waiting on some caps to come in this week and I'm back in business. I am going to use the 24vdc supply I have here. I will save the 53vdc supply for servos if I ever go that route. I see your working on a servo driver. I would give that a try when its ready. I could always use a second machine...you know, bigger, faster...all that stuff! :boxing:

BobLWeiss
12-30-2004, 07:09 AM
Juat a note, do you know you can get samples of these chips for free from National Semiconductor? They will send you 5 of them from their website. I also got 5 of those chips Alan that you are using for the servo driver. The H bridge chips. I used my work address and had them send 5 more so that's how I had spares..these babies are like $12.00 a peice in the stores. If you have an email address that is from like earthlink, comcast etc..they want you to pay $29.00 for shipping but they will still send them. That's still a nice savings for 5 chips.

Garfield2
12-30-2004, 07:47 AM
Juat a note, do you know you can get samples of these chips for free from National Semiconductor? They will send you 5 of them from their website. I also got 5 of those chips Alan that you are using for the servo driver. The H bridge chips. I used my work address and had them send 5 more so that's how I had spares..these babies are like $12.00 a peice in the stores. If you have an email address that is from like earthlink, comcast etc..they want you to pay $29.00 for shipping but they will still send them. That's still a nice savings for 5 chips.

Funny that's how I got mine too.. :)

Although I am actually developing something with them. I hate seeing samples wasted (not to say you're going to waste them, I'm just generalising, don't mind me :)), otherwise they'll stop the service or make it harder to obtain.

Unfortunately there is no such thing as a free lunch. :)


Alan.

santiniuk
12-30-2004, 08:22 AM
I can never seem to get the holes to line up... those damn layers!... Plus soldering in short pieces of wire in the vias is such a pain, man I wish I had a hole plating machine!

Oh I hear you on that Alan !

I remember the time I tried to make a double sided board. Not good memories. In fact I'm sure I had the artwork's in reverse on one side so it was a total waste :rolleyes:

In fact how I enjoyed making those wire links..... Can You add some more next time :)

Good to hear your back on track Bob, thanks for the heads up with the voltage caution.

No progress here at the moment.....

santiniuk
12-30-2004, 09:14 AM
Well looks like I'm building another set of boards. My friend is itching to make a start.

I sent him a small video clip which he has hosted on his unused webspace.

Picstep Test Video (http://www.mikeep.btinternet.co.uk/picstep.zip)

I think it's a virtual mill of a Picstep board in progress !

Garfield2
12-30-2004, 05:28 PM
In fact how I enjoyed making those wire links..... Can You add some more next time :)

I already removed some for you! Now you want me to put them back! hehehe :rolleyes:

I still think I could possibly route it a little better, but not much. It quite time consuming to get it just right.. :)

I'm busy with the firmware for PICServo now, it's progressing nicely! These new boards will have a 16x2LCD that will act as a DRO and also a control interface to setup the PID gains and adjust the step lengths etc etc. I'm working on the RS232 comms routines now. It's looking good!

I might have to start charging for this firmware.. :)

Cheers,
Alan.

MrBean
12-30-2004, 05:38 PM
Incase you guys building PICStep havn't checked Alan's site recently. He's taking donations, if you like his design.

I for one, have made a donation for the hard work that Alan's put in. For me, it's well worth the money.

Thanks again Alan.

Regards Terry.....

BobLWeiss
12-30-2004, 06:27 PM
Well I got my parts today and rebuilt 1 of the boards. I now have 2 functional drivers. I am working on the third now. Should be back to where I was by tonight. Tomorrow I plan on cutting and finally getting to see how this bad boy works. I have to fine tune TurboCNC feedrates etc so that will be fun...

Alan, nice to hear your working on the Servo board. I for one would love to check it out!

santiniuk
12-30-2004, 06:38 PM
Totally agree Terry. Donation on it's way. Actually just noticed that we have * Fame * on Alan's site...

Gallery look's great... I just want to make a silk-screen now !

Hey Bob you could have a New Year Celebration switch on :) Look forward to the pictures.

Cheers

BobLWeiss
12-30-2004, 07:03 PM
Just made a donation to Alan! I would certainly pay for something that saved me a bunch of baord design work and agony of prototyping! Thanks Alan!

Well just finished board 3! Back in business fellows! Working on securing it all to a piece of wood so its nice and neat and I can move it around when needed. I am cutting tonight!!!! By the way, anyone have any cool Gcode files they could send me so I can try it out? Something like artwork I can cut out in wood so my wife sees the potential...(hint, more money!) :cheers:

MrBean
12-30-2004, 07:09 PM
Hey Bob you could have a New Year Celebration switch on :) Look forward to the pictures.

Cheers


Carefull. Bob had fireworks too at his last switch on. (flame2)

Seriously though. Bobs misfortune may well save others from the same fate. (like me). I was planning for a 35V secondary transformer ~50V DC. Have now deceided on 25V secondary ~35V DC.

Many thanks to you Bob.

Regards Terry.....
http://www.terry-is.f2s.com/

Garfield2
12-30-2004, 07:19 PM
Guys, I've posted some simply assembly instructions on my website. It has some of the lessons learned in this forum and by other guys via email. Plus I walk step by step through the assembly process hopefully making it easier for more people to build.

Let me know if there are any mistakes.

Many thanks,
Alan.

Garfield2
12-30-2004, 07:22 PM
Well looks like I'm building another set of boards. My friend is itching to make a start.

I sent him a small video clip which he has hosted on his unused webspace.

Picstep Test Video (http://www.mikeep.btinternet.co.uk/picstep.zip)

I think it's a virtual mill of a Picstep board in progress !

Wow that's so cool.. :)

Mind if I put this on my website?

Alan.

Garfield2
12-30-2004, 07:31 PM
Carefull. Bob had fireworks too at his last switch on. (flame2)

Seriously though. Bobs misfortune may well save others from the same fate. (like me). I was planning for a 35V secondary transformer ~50V DC. Have now deceided on 25V secondary ~35V DC.

Many thanks to you Bob.


Indeed! I'm 10 hours ahead of GMT, so I'll look north towards the USA at around the US midnight for Bob's fireworks.. I'll be sitting on my lawn drinking a nice cool beer while I admire Bob's handywork from here :cheers:

I'm actually going to the CES show in Las Vegas on January 8th->10th, I fly out on Jan 2nd to HK for a few days then onto the USA.

Anyway I hope it goes smoothly Bob, should be good to see a machine that actually "uses" PICStep rather than a bunch of guys with spinning motors (myself included!).

I've put the warning regarding the greater than 40VDC in the build instructions, hopefull no one else has to suffer that pain! (sorry Bob!)

Post more photos when you're done, so I can keep the gallery up to date!

Cheers,
Alan.

PS Happy neuooo yeeear!

BobLWeiss
12-30-2004, 08:10 PM
At least it was cool looking! :cool:

Seriously, be careful when working with high voltages...could be a big problem if your not qucik enough to disconnect power. (chair)

I am playing around with TurboCNC's settings now..trying to get the best setup. Currently using the 1/8th step mode...seems to give the best results so far in terms of speed. I will let you all know what the optimum settings I get when I'm finished.

Bob

MrBean
12-30-2004, 08:14 PM
At least it was cool looking! :cool:

Seriously, be careful when working with high voltages...could be a big problem if your not qucik enough to disconnect power. (chair)

I am playing around with TurboCNC's settings now..trying to get the best setup. Currently using the 1/8th step mode...seems to give the best results so far in terms of speed. I will let you all know what the optimum settings I get when I'm finished.

Bob


Could you also give your motor specs. May make the numbers more meaningfull.

Thanks.

Terry.....

MrBean
12-30-2004, 08:32 PM
In fact how I enjoyed making those wire links..... Can You add some more next time :)

Yes. Those wire links are really handy. Now the police will never trace me.....

BobLWeiss
12-30-2004, 08:46 PM
Hahaha I know what you mean..ouch, typing is even hard! :rolleyes:

BobLWeiss
12-31-2004, 06:21 PM
Well I got my system up and running!!!! :cheers:

It took me all day to sort out the wiring and fine tune the setup. I am still working on the settings, I am going to test cut some stuff tonight and let you know what settings I ended up with. I am running with no jumpers on the breakout board which is 1/8th microstepping mode. Moves nice!!!

Here are some pictures...

http://www.cnczone.com/gallery/data/500/7080Bobs_System_11.JPG
http://www.cnczone.com/gallery/data/500/7080Bobs_System_21.JPG
http://www.cnczone.com/gallery/data/500/7080Bobs_System_31.JPG

chuckknigh
01-01-2005, 12:47 AM
What did you use for slides? It looks like they mounted quite nicely...

-- Chuck Knight

santiniuk
01-01-2005, 07:42 AM
Well the New Year is here. I wish you all a peaceful one.

It's good to see the machine in it's full glory Bob, some real nice work there !

I'm also interested in the slides, and the overall materials.

Have you any tips for someone just about to start building ?

What would you change ? What are the tricky bits ? Time to build ?

Have you cut anything to impress your wife yet :)

@Terry, Man I had to take a double look there :) Reminds me of the time I was learning to play the guitar.....

@Alan, feel free to use any images or video I post here.. I take it as a compliment.

All the Best.

Shaun

BobLWeiss
01-01-2005, 08:09 AM
What did you use for slides? It looks like they mounted quite nicely...

-- Chuck Knight

Drawer slides from Home Depot. They work great, I mounted them so there is no noticable play in any direction other than side to side which is what you want anyway.

BobLWeiss
01-01-2005, 08:13 AM
What would you change ? What are the tricky bits ? Time to build ?

It took me about a month and a half to build, alot of that time was waiting for glue or paint to dry overnight. I made it out of MDF and drawer slides. If I was to build it over I would have made it gantry style to allow more movement in the x axis but what it has now (11") is good enough for what I'm using it for anyway. I started to cut out the a ruler in some scrap MDF using a file I downloaded from a site. It came out good for a bit then messed up. I need to come up with a way to hold down work on the table. That will be the project of the day.

BobLWeiss
01-01-2005, 04:10 PM
Well I decided to rebuild my Z axis and not use the pre-built one in the photos. The reason is it is more for PCB work and doesn't give me enough depth of cut to do any wood stuff. I would rather have a Dremel on there and I happen to have an extra one of those laying around and an extra pair of 16" drawer slides. I also have a stepper with 10" lead screw and nut attached to it. I will post pictures of when complete. I am waiting on paint to dry now, should be done by tonight.... I guess that's why they call it a hobby, never ending....my wife thinks I'm nuts..... :cool:


Shaun:
Did you start on your machine yet?

MrBean
01-01-2005, 07:24 PM
Hey bob, you're making good progress. How's the PICStep dirvers working out, or have you not had a chance to really test them yet?
Nice to see some pictures of your machine. What are the stepper motor specs?

Terry.....

BobLWeiss
01-01-2005, 08:49 PM
Hey bob, you're making good progress. How's the PICStep dirvers working out, or have you not had a chance to really test them yet?
Nice to see some pictures of your machine. What are the stepper motor specs?

Terry.....


The drivers are working great. They are really worth building in my opinion.

As for the specs of the motos, they are NEMA 23's, and rated at 80 oz/in. 5v, 1.1amp

I thought that they may be a little too weak for the machine but they surprised me and run fabulous. I am getting like 19 IPM feed rate running at 24vdc power supply. The only thing better motors would give me at this point is speed. I can't really get a handle on that yet until I start cutting and measuring the time it takes to complete something. I am going to be milling the PICSTEP boards as a test to see how long it takes to mill and drill one board.

Bob

MrBean
01-02-2005, 06:14 AM
The drivers are working great. They are really worth building in my opinion.

As for the specs of the motos, they are NEMA 23's, and rated at 80 oz/in. 5v, 1.1amp

I thought that they may be a little too weak for the machine but they surprised me and run fabulous. I am getting like 19 IPM feed rate running at 24vdc power supply. The only thing better motors would give me at this point is speed. I can't really get a handle on that yet until I start cutting and measuring the time it takes to complete something. I am going to be milling the PICSTEP boards as a test to see how long it takes to mill and drill one board.

Bob


Bob. I've updated the DXF's and g-codes. Better placement of holes and none missing this time. Also there are 3 seperate drill files for the different sized holes.
If you would like them, I'll put them on my site for download. Just let me know.

If you plan on using the milled board you may want to have these.

Regards Terry.....

santiniuk
01-02-2005, 08:10 AM
Shaun:
Did you start on your machine yet?

Not yet Bob,

I'm back to work on the 4th. I have a few items salvaged, some rails etc. There is some aluminium profile that may be available too.

So when I'm back it will be easier to see what bit's are available.

Just enjoying seeing your progress at the moment :)

Cheers

BobLWeiss
01-02-2005, 08:57 AM
Bob. I've updated the DXF's and g-codes. Better placement of holes and none missing this time. Also there are 3 seperate drill files for the different sized holes.
If you would like them, I'll put them on my site for download. Just let me know.

If you plan on using the milled board you may want to have these.

Regards Terry.....

Thanks! That will save me a bunch of time generating them myself. I am only going to cut out 1 to test the accurcy of the machine. I already have the 3 built (save this one for a 4th axis do the road :cool: )

MrBean
01-02-2005, 11:59 AM
Thanks! That will save me a bunch of time generating them myself. I am only going to cut out 1 to test the accurcy of the machine. I already have the 3 built (save this one for a 4th axis do the road :cool: )

The updated files are now on my website for milling picstep. Help yourselves.

http://www.terry-is.f2s.com/

Regards Terry.....

BobLWeiss
01-02-2005, 07:33 PM
Well finished building the new Z axis...works great!

http://www.boblweiss.com/images/IM000284.jpg

I cut out the ruler G-code and it was dead on the money in terms of accuracy...Now I am going to purchase TurboCNC so I can set all the settings permantly. Its a drag that it won't save the configuration settings in demo mode...kind of makes it hard to evaluate it..oh well.

santiniuk
01-03-2005, 06:00 AM
Wow that Z-axis came together well !

It's looking like the business now.

Time to reap the rewards of your hard work.

Although I'm not looking forward to going back to work after a holiday, I certainly cannot wait to kick off my mechanical construction !

Bob you mentioned some g-code files you had found above. Any chance of posting them here.

Thanks

BobLWeiss
01-03-2005, 03:27 PM
I will post the Gcodes once I get them cut out myself to make sure they are good. The program DeskEngrave is nice if you need to engrave text on something. I had a problem with my Y axis going in the wrong direction. I fixed that problem...just changed the wiring. Now its working nice!

BobLWeiss
01-03-2005, 07:34 PM
Mr Bean:

I am playing around with your files for the PICSTEP board and I am having problems like you did with the table not being exactly flat. First of all how did you solve that problem? Where did you get the bits from? Which ones?

Thanks,
Bob

MrBean
01-04-2005, 06:01 AM
Bob. I screwed a piece of MDF on the table and surfaced it off with the largest cutter I had for my Dremel. You have to be careful with the MDF though as the hard coating is very thin. If you go right through, it goes all fluffy.

You could use somthing more stable than MDF to create a flat surface but it's ok for small runs.

To do the surfacing I just jogged the machine manually over the piece to be surfaced off. You could easily make a toolpath to do this for you though.

Hope it goes well.

Regards Terry.....

MrBean
01-04-2005, 06:23 AM
I forgot to say that I ended up holding down the plain copper board, to the new flat surface, with double sided tape. Seemed to work very well, and easy to do too.

Regards Terry.....

santiniuk
01-04-2005, 04:35 PM
Back to work and back to the grind..... :(

Salvaged some bits and decided to draw & model them up as I obtain them.

It will probably be easier for me to 'virtually' construct it before the building starts.... And so here is my first query.

I have two rails and each rail had only one carriage fitted. I thought I would use this for my Z-Axis as it has enough travel. I'm unsure if I can get away using only the one carriage per rail. I seem to see them used in pairs per rail.

Any comments - Will the one carriage per rail be ok for the Z-Axis movement ?

Thanks

MrBean
01-04-2005, 04:41 PM
That's the exact set-up I have on my machine for the Z axis. No doubt 2 trucks per rail is better but I found that 1 per side works ok.

Regards Terry.....

kong
01-04-2005, 04:43 PM
I would go for two if you can, there is trememndous pressure on the z, so only use 1 if you are using an extremely short bracket, or unless the bearing blocks are very long! You can often buy carriages quite cheaply on ebay since people onyl want a complete assembly - maybe worth checking out the US site?

ger21
01-04-2005, 05:47 PM
Now I am going to purchase TurboCNC so I can set all the settings permantly. Its a drag that it won't save the configuration settings in demo mode...kind of makes it hard to evaluate it..oh well.


There is no "demo mode" for TurboCNC..??? Not that you shouldn't pay for it, but purchasing just gets you the source code.

BobLWeiss
01-04-2005, 06:29 PM
Yeah I found that out. Someone on their Yahoo Group told me there was then I was told there wasn't. I found the problem, the ini file was set as READ ONLY so it wouldn't save anything. Stupid..

I have it all working now.

Bob

BobLWeiss
01-06-2005, 10:27 AM
So haven't heard from anyone lately, just checking in to see how the progress is going?

I am flattening my X axis table by using the idea from Mr.Bean, I am letting the dremel (Z axis) cut the top layer off of it by going over every inch of the table. This will help big time when it comes to doing circuit board since .01 of inch is critical.

I also have a little too much backlash in my Y axis and going to work on that tonight. I have a feeling the way I mounted the nut to the backboard has become loose and its at leat 1/2" of play with it now..WAAAYYYY too much for me.

PicStep is working brilliantly and I am starting to like TurboCNC 4.0 alot. I plan on giving Mach2 a try this weekend and then make my choice.

Looking for a good CAD program now but I do not want to spend $$$ on one that does more than what I will use it for. There are alot of choices out there, and salesmen love to call you 3 times a day too. I downloaded the demo version of BobCAD...this guy must have called me 10 times since then asking me to buy it...Damn, I didn't even really get a chance to use it yet and he is making all kinds of deals for me...Makes you not want to buy it just because of that alone.

santiniuk
01-06-2005, 06:02 PM
Still pulling stuff together at this end Bob.

I mentioned to someone that I had turned into a skip rat which is quite appropriate.

Not doing too badly, I should manage to get enough MK aluminium profile to make the frame components. I have a couple of linear rails that should do for the Z axis and Possibly a ballscrew for the Y drive. I'm putting a bit of time into the cad side which I'm finding rewarding. If it goes together on screen it should in the end ! Well thats the plan...

I do have a query. I found a stepper rated at 2.5V 4.5A - Is there anyway this can be used with the picostep boards. (Rated 3A)

Cheers

BobLWeiss
01-06-2005, 06:09 PM
Still pulling stuff together at this end Bob.

Glad to hear your still at it!


I do have a query. I found a stepper rated at 2.5V 4.5A - Is there anyway this can be used with the picostep boards. (Rated 3A)

I don't see why not, you will not be getting 100% of the torque out of the motor since you are not giving it max current but you shouldn't need it anyway. My Z motor is rated at 1.1amps, 4vdc and I move a dremel around like its nothing. I wouldn't worry about it all..

Bob

MrBean
01-06-2005, 06:10 PM
I do have a query. I found a stepper rated at 2.5V 4.5A - Is there anyway this can be used with the picostep boards. (Rated 3A)

Cheers


Just set the current limit on picstep to 3A or maybe a bit lower to be safe.
The motor will work just not at full power.

I'm still waiting for a few parts to finish my PICSteps. Toroid transformer turned up today. Yippeee.

Had an accident with one of the semi populated boards. Trod on it. SNAP.
Need to mill another, but now waiting on some more copper clad.

Should all be up and running next week sometime.

Regards Terry.....

santiniuk
01-08-2005, 09:33 AM
Thanks for the info. Did a quick trial and set the current limit resistors to a value just under 3A. I made sure that I had fitted the 1uF caps missing previously.

Using a 12V supply the motor runs fine. I noticed the heatsink getting warm on the LMD device so would change this if I use the larger stepper.

It certainly seems powerful !

santiniuk
01-08-2005, 09:38 AM
Not sure if It's much use but rescued a Lambda LT-801 PSU. It's rated 0-7.5V 150A !!!

Quite good condition, need to find some information on the Supply wireup as it's just a terminal strip. There are also a terminal block with light wires on it.

Pic's for info.

santiniuk
01-08-2005, 09:41 AM
Next item rescued is a sealed ballscrew unit I believe. It's like a pneumatic cylinder but driven by a 10mm shaft.

Body of the unit is 450mm long and carriage on top 150mm * 36mm

Feels quite smooth and very little backlash. Z-Axis maybe ???

santiniuk
01-08-2005, 09:45 AM
This one is a beauty.... But there is only one.... :(

It's a linear rail with two carriages on.

Rail length is 600mm 20mm*15mm. Carriage is approx 65mm*40mm
Fixing holes are spaced at 60mm

Not sure what to use this for !

santiniuk
01-08-2005, 09:48 AM
Another nice find.

Two rails 350mm 20mm*15mm

Some slight tarnishing of the rails at the ends but actually run smooth.

Fixing spacing 60mm and carriages are approx 43mm*43mm THK SR

Any tips on how to clean these up ?

BobLWeiss
01-08-2005, 09:53 AM
If you told us before I am sorry I forgot, but what kind of work do you do? It seems like you can get your hands on alot of CNC type equipment..nice finds.

That power supply would work but the voltage is a little on the low side. I would shoot for 24vdc range.

Bob

santiniuk
01-08-2005, 09:55 AM
Not sure what to use these for !

Either skip them, use them as Ski's or attempt to clean them.

It's a pair of linear rails that have been painted at the sides and ends ! :(

They are 1300mm long. 20mm in height, base wide 20mm and top of rail is approx 31mm wide...

Fixings at 125mm spacings.

No carriages with them.....

Really not sure if these are good to man or beast.....

Any tips on how to remove paint appreciated :)

santiniuk
01-12-2005, 04:57 PM
Well it's not a lot but finally had linear movement tonight.

I'm not sure if it's suitable for my Y-Axis plans but it moves !

Thanks to Terry for providing the assembly.

Originally I intended to use MDF but now intend to use Aluminium MK profile for the frame. This is going to take longer for me to work with but I'm in no real hurry.

I experimented with the microstep jumpers on the picstep boards and it works extremely well.

A couple of pictures attached and a small video for info.

Appreciate any advice on the suitabilty of this assembly.

Cheers.

Ballscrew Video (http://www.mikeep.btinternet.co.uk/ballscrew.zip)

BobLWeiss
01-12-2005, 05:48 PM
Thats some nice speed...what did you use to move it? (software?)

santiniuk
01-12-2005, 07:17 PM
Bob,

It's a demo of Kcam 4.

It's just what was running at the time as I'm working my way around a few.

I prefer using the windows environment.

Alan, any progress on the isolated interface board. I'm keen to take away any risk of killing my laptop.... Already had a scare due to being careless :)

Cheers.

Garfield2
01-12-2005, 07:38 PM
Alan, any progress on the isolated interface board. I'm keen to take away any risk of killing my laptop.... Already had a scare due to being careless :)


:)

Opto ain't going to correct carelessness.. :P

And no, I've only just got back from CES in Las Vegas, and I'm struggling to get back into the swing of things. Plus I'm a fair way down the PICServo path at the moment so my design time I do have is devoted to that at the moment.. I'll see if I can squeeze it in somewhere in between. Otherwise just use a USB parallel port on your laptop and live happy.. :)

Alan.

MrBean
01-13-2005, 12:53 PM
My PICStep is up & running. (only 1 board on the desk at the moment though.)

My Z axis motor has increased in speed from 4.3 IPM with the old drivers, to 44 IPM with PICStep. That's at 12V, 1A. As I don't have any heatsink for the LMD's yet.

That means there's more speed to come when I get my 35V supply built & some heatsinks.

My Z axis is slow anyway as it's 5mm pitch ballscrew, geared 3:1. Effectively making it 1.66666mm pitch. Plenty of torque though, to lift that router.

Thanks to all who've helped. Especially Shaun and Alan.

PIC's are working fine. At least the one I've tried is. Thanks Shaun.

Once te motors and drives are back on the machine I hope to get some video to post.

Regards Terry.....

santiniuk
01-14-2005, 03:01 PM
Hey Terry that's great news !

Good to hear it all came together in the end, Sounds like a huge improvement for you.

I noticed that your cnc is a movable table. Are you happy with this ?

Are there any major disadvantages or advantages with this over a moveable gantry ?

I think my ballscrew assembly lends itself more to a moveable table. Not sure however.

Looking forward to seeing some video from you.

Cheers

MrBean
01-14-2005, 05:43 PM
Yes. The drivers look like they'll improve the machine quite a lot. I have still only tested the one driver / motor. I've mounted all the drivers and interface on a board, on a wall near the machine. I'm going to run them at 13.8V, 1A, untill I get some heatsinks made. So far I've had no resonance from the motors in 1/4 and 1/8 step modes.
Hopefully tomorrow I'll get all the new stuff wired in for some real testing. I have a solid state relay for spindle control to wire in aswell as a new mushroom type E-stop button.

Can't wait.

Regards Terry.....

MrBean
01-15-2005, 10:07 PM
Just curious. Anyone know why pin 14 on the PICStep interface board is not connected to anything. Mach2/3 uses this pin as an output. It's not really an issue, as I'm not using all the outputs anyway. If I ever need it I can always solder a signal cable onto the underside of the board.
Just seems strange not to have it connected to a header.

Regards Terry.....

Garfield2
01-15-2005, 11:44 PM
Just curious. Anyone know why pin 14 on the PICStep interface board is not connected to anything. Mach2/3 uses this pin as an output. It's not really an issue, as I'm not using all the outputs anyway. If I ever need it I can always solder a signal cable onto the underside of the board.
Just seems strange not to have it connected to a header.

Regards Terry.....

I originally was going to connect it up to the six pin output header, but I decided I wouldn't because I remember reading somewhere that on some parallel ports pin 14 couldn't drive very much load or had some strange I/O arrangement or some such. So rather than be sorry I chose not to implement it, plus I figured I had enough outputs anyway!

Cheers,
Alan.

MrBean
01-16-2005, 06:21 PM
I got my PICStep boards wired up to my machine.

X axis is fine, 600 IPM rapids
Y axis is fine, 120 IPM rapids
Z axis works nice in one direction but really choppy in the other. Sound like missing steps........

I had a small problem with the Z axis board. There was some debris in one of the milled channels between two of the tracks. It shorted and burned the debris away. If one of the LMD's were damaged surely it would effect motion in both directions or not work at all.

Seems like step pulse is ok, as it's working in one direction. Could it be interference on the direction line? Thing is, all the wires from the LPT port are ribbon cable so I'd expect interference on more than just the one line.

I'm using Mach2. Anyone have any ideas what's causing Z problems in one direction only.

Regards Terry.....

Garfield2
01-16-2005, 06:33 PM
I had a small problem with the Z axis board. There was some debris in one of the milled channels between two of the tracks. It shorted and burned the debris away. If one of the LMD's were damaged surely it would effect motion in both directions or not work at all.


One half of a h-bridge in one of the LMD's could be damaged. You may find in one direction the duty cycle of one half of one of the h-bridges is about 30-70. But in the other direction it's 70-30. You may find in the direction it's seems like it's working the other half of the h-bridge is doing most of the work, but in the opposite direction it's suppose to be doing most of the work and failing at it.

Also if the short was across the digital IO lines to the LMD's the DAC in one of the LMD's could be damaged and wigging out in the opposite direction.



Seems like step pulse is ok, as it's working in one direction. Could it be interference on the direction line? Thing is, all the wires from the LPT port are ribbon cable so I'd expect interference on more than just the one line.


Easy way to check to see if it's the board or the cabling, is to swap the Z axis driver with one of the other working ones. If it functions correctly in the Z axis position you'll know it's a fault with the Z-axis driver board. If the fault appears the same and the Z-axis driver works in the other boards position then it's external and could be interference.

How long is your parallel cabling? The frequencies used to drive the step/dir lines steppers shouldn't cause to many problems at low stepping speed. You'd normally only see interference when they're going flatout!

Cheers,
Alan.

MrBean
01-16-2005, 06:54 PM
See picture of where the short occoured. Looks like quite a few bits got hit with the 36V stepper supply. Oh bugger.

Will swap the drives tomorrow, to check out your suggestions.

If I killed it, what would you say will most likely need replacing? Or should I just build a new driver.

Thanks for the help.

Regards Terry.....

Garfield2
01-16-2005, 07:22 PM
See picture of where the short occoured. Looks like quite a few bits got hit with the 36V stepper supply. Oh bugger.

Will swap the drives tomorrow, to check out your suggestions.

If I killed it, what would you say will most likely need replacing? Or should I just build a new driver.


Crumbs! It's amazing it's working at all.. :)

The 5V supply got a 36V wack, so both the LMD's and the PIC would have had 36V up their 5V lines. The PIC has a maximum supply voltage of 6.5V so it could be the PIC causing all the grief. The LMD's on the DAC ref will take 12V, so it could be the DAC in one of the LMD's is stuffed.

The fact the PIC seems to be working I'd tend to think it's probably not at fault. Check the direction line from the PIC pin 12 to see if you get 0 and 5V when the controller is stepped slowly through it's sequence.

I'd be suspicious of the left most LMD for a fault. It would have got wacked in it's direction line and it's DAC ref line. Something small there could be dead. That would be the first component I'd replace.

Cheers,
Alan.

MrBean
01-16-2005, 07:43 PM
Many thanks. Lots to check out. First off I'll swap the Y & Z drives round. Should find that Y is now choppy in one direction and Z is working fine. Next I'll swap the PIC's in Y & Z to eliminate that from the equation. If all goes to plan thus far, it'll mean replacing the LMD's, unless the PIC shows to be faulty. Will let you know how it goes.

The two axis I didn't blow up, are fantastic. PICStep rocks.

Regards Terry.....

MrBean
01-16-2005, 07:47 PM
What would be handy, is to fit some status LED's into the design. You could then visually see the dir line changing HI - LO via two led's or a bi-colour. Maybe others could be usefull too.

Regards Terry.....

Ferenczyg
01-17-2005, 09:13 AM
Not sure what to use these for !

Either skip them, use them as Ski's or attempt to clean them.

It's a pair of linear rails that have been painted at the sides and ends ! :(

They are 1300mm long. 20mm in height, base wide 20mm and top of rail is approx 31mm wide...

Fixings at 125mm spacings.

No carriages with them.....

Really not sure if these are good to man or beast.....

Any tips on how to remove paint appreciated :)


I don't know the exact name in english, in spanish that product sounds like 'decapping gel'. Its a kind of product with gel consistency that you apply with a stencil, and makes the paint to bubble and separe from the surface is applied. Be careful and use latex gloves, is very irritant to the skin. The good think is that does not have abrasive properties at all so will not apply any wear to the linear guides.

Hope it helps.
/Fer

MrBean
01-17-2005, 08:26 PM
Hi. I've swapped the drives around and got the Z axis moving with both the other boards. One of the LMD's is definately dead on the remaining board. Not sure on the other one. Have ordered 2 more LMD's and will build a complete new board. The PIC survived the 36V hit. Tried it in the 2 working boards, checked out OK.

So, 2 out of three aint bad, as Meatloaf would say......

I took the opportunity to have a fiddle with the settings in Mach2. I got my X axis rapids up to 850 IPM. Thats with no missing steps. resolution is 0.001"

Y axis 100 IPM. No missing steps. Resolution is 0.000056"

Z axis. Well I blew it up (chair) It's going no where at the minute. I'll have to put the crappy full step driver back on Z, to mill the new board.

Other than that I'm having fun.

If you're going to do something wrong, at least enjoy it!


Regards Terry.....

BobLWeiss
01-17-2005, 08:37 PM
Do you mind sharing your drive specs? How you have them wired? The best speed I can get out of mine running at 24vdc, 1A per phase is 15IPM. My lead screw is 16TPI and if I push it any faster it stalls out. Just wondering how you can get such high speeds..

By the way, sorry to hear about your bad LMD. When I first used the bigger supply I thought I fried everything, here I only fried 2 LMD's, one on each board and the Pics. Not sure why the pics went, probably due to the LMD shorting out internally.

Bob

MrBean
01-17-2005, 08:51 PM
Do you mind sharing your drive specs? How you have them wired? The best speed I can get out of mine running at 24vdc, 1A per phase is 15IPM. My lead screw is 16TPI and if I push it any faster it stalls out. Just wondering how you can get such high speeds..Bob


Hi Bob. My motors are 6 wire (Unipolar). I've wired them as bipolar half winding. They are rated 110 oz/in. 5.1V 1.3A. I've only tried them up to 1A (75% power), as I have no heatsinks on the LMD's. Running voltage is 36V.

My X figures are high as it's belt driven and as such, is fairly low resolution without having multiple step down pulleys.

Y figures are more normal. 5mm pitch ballscrew geared down at roughly 2.2:1

The X axis nearly shot off the end of the machine when it moved at 850. Scary.

What's your set-up. Motor wiring confuguration etc...? If I recall, you're using all-thread which will have much higher fricton to overcome than ballscrews or beltdrive.

Regards Terry.....

MrBean
01-17-2005, 08:58 PM
Oh yeah, I forgot. Mach2 is running the motors. Also I'm running 1/8 step mode.

Garfield2
01-17-2005, 11:01 PM
What would be handy, is to fit some status LED's into the design. You could then visually see the dir line changing HI - LO via two led's or a bi-colour. Maybe others could be usefull too.



Speak and ye shall receive! PICStep V3.0 is on my website. No ICSP, and status LEDs. :)

http://www.fromorbit.com/projects/picstep/

Cheers,
Alan.

santiniuk
01-18-2005, 04:30 AM
How about that for service ?

Great work Alan. :)

I mentioned earlier in the thread a friend was interested in building a machine. I will be helping him out with the electronics. So will be building Picstep 3 sometime soon...

Meanwhile I'm still building my machine virtually in CAD. It's taking shape slowly.

Enjoying reading your post's Terry. Keep's the incentive going for me.

Cheers

BobLWeiss
01-18-2005, 10:36 AM
What's your set-up. Motor wiring confuguration etc...? If I recall, you're using all-thread which will have much higher fricton to overcome than ballscrews or beltdrive.

Regards Terry.....

Thanks for sharing..I am using 3 different motors, the X axis is rated at .8a and 4vdc. The Y axis is 1.1a, 5vdc and the Z is 1.1a, 3vdc. My X axis motor is running too hot at 1amp per phase wired in parallel. I just ordered 2 new motors that are rated at 2 & 3amp per phase so I can feed it more amps and not have to worry about leaving it running on its own. I am also building a new powersupply that will put out 30vdc, 15amps (compared to 24vdc, 6amps that I am using now) so I should get a little more speed with that.

I am using all-threaded rods so I can see now why I don't get the speed you get with pulleys and belts. My Z axis is fine since its using a 5 start lead screw that has 2 TPI. I also have PICSTEP setup to run in 1/8 mode.

Bob

mvaughn
01-18-2005, 03:36 PM
I've been following this thread trying to learn more about Alan's PICSTEP drivers.

What I've found so far is a great deal of information on how to build the actual circuits. However, I'm at a loss for how to connect it all together after the circuits are built.

I have a list of questions and would be grateful to anyone who can answer them for me.

It appears that the PICSTEP will work with 6 wire unipolar steppers; is that correct?

Is there any documentation that depicts how to make the parallel port to BOB cable?

Is there a particular way that the driver boards need to be connected to the BOB? (ie special cable pinouts...)

I think this is a great driver board and Alan did a fantastic job. It would be really great to make this board easy to use for the people with limited electronics experience.

santiniuk
01-18-2005, 03:54 PM
mvaughn,

I'll try and answer what I know.

The attached picture should show you how Terry has connected his 6 wire motor to the Picstep boards. (Resulting in connecting 4 wires only)

The Parallel port to Break Out Box cable is simply a matter of using a 26 way ribbon cable with IDC connectors at either end. On the BOB pcb the 26 way IDC is used and on the parallel port a 25 pin D connector is used. Simply ignore the unused 26th wire.
For the IDC assembly I used a vice to 'gently' squash the connectors to the ribbon ensuring that the ribbon is square at all times.

I would go the IDC route personally as it's a few minutes to assemble. If not its a few wires to solder but I have not seen a full pinout - pinout diagram in the docs.

Totally agree with your comments. Great design. And now with v3 out some leds to watch too :)

Garfield2
01-18-2005, 03:59 PM
It appears that the PICSTEP will work with 6 wire unipolar steppers; is that correct?

Yes, if you can wire it's coils up in a bipolar configuration ie. two coils


Is there any documentation that depicts how to make the parallel port to BOB cable?

The BOB cable is just a 26way IDC header socket crimped to 26 way ribbon cable with a 26 way IDC DB 25 crimped on the end. As long as all the pin 1 arrows all point to the red wire (or that same wire if you don't have a red index wire) in the ribbon you really cannot go wrong.



Is there a particular way that the driver boards need to be connected to the BOB? (ie special cable pinouts...)

Nope, as long as you connect the 10 way IDC connectors between the BOB and the driver boards with pin one pointing to arrows and your cable is made with arrows pointing to the same wire (the red wire in the 10 way IDC cable)


I think this is a great driver board and Alan did a fantastic job. It would be really great to make this board easy to use for the people with limited electronics experience.

Why thank you. There are build instructions available on my site if you get stuck..

Cheers,
Alan.

mvaughn
01-18-2005, 04:31 PM
Thanks for the quick replies guys.


It looks as the BOB has headers on it that appear to be connections for home and limit switches, but I'm not sure. Can you explain each of the marked areas in the pictures?

Thanks

Garfield2
01-18-2005, 05:05 PM
Thanks for the quick replies guys.


It looks as the BOB has headers on it that appear to be connections for home and limit switches, but I'm not sure. Can you explain each of the marked areas in the pictures?

Thanks

1 - Power supply for the 5V+ regulator and Emergency Stop Button (engages the brakes on the drivers)

2 - BOB Output header. It has 3 pins from the parallel port you can use to control relays to turn on and off your coolant, routers, whatever. It requires an addition board/circuit to drive the relays. It's there for the more advanced person who need this functionality and can figure it out themselves. You can safely ignore it.

3 - Limit/Home switches 5 in total

4 - ICSP socket. This is an in-circuit programming socket so you can program the PIC while it's mounted to the board with an ICSP capable programmer. The DIP switches isolate the PIC so the programmer can function correctly.

Cheers,
Alan.

mvaughn
01-18-2005, 05:23 PM
Wonderful, thanks Alan.

Regards,
Mark

santiniuk
01-19-2005, 03:38 PM
Having the reputation of being a skiprat has it's benefits at work. I seem to get first chance offer on anything no longer required. This weeks salvage is an old HP Laserjet 4+ printer.

This old workhorse has a page count of 149,000 but it still seems to print as good as new. (The printer was being replaced with a colour version).

It's a shame that like a lot of pc peripherals the grey / cream housing has now got that yellow look. Is there any magic cure to restore these discoloured housings ?

After reading about making pcb's using the toner transfer method I thought I would give it a bash.

I only have some Kodak glossy picture paper so thought the Picstep v3 would be a good experiment.

The image printed really well onto the glossy side of the paper. I set the toner denisty to maximum and was pleased with the image quality.
As this is my first attempt at making a pcb with laser toner I was guessing at what temp the iron should be and for how long to iron it for.
The wife was in shock when she saw me with an iron in my hands :)

After ironing for a few minutes I then put the board in a bowl of water and was expecting the paper to go to mushy but it didn't. The paper has a plastic like feel so maybe it's the wrong type.

As a last resort I peeled the paper off the copper and was surprised to see the toner had bonded to the copper and literally peeled of the paper. Hard to explain but it reminded me of rub down transfers.

The end result is not great but It's certainly got me interested in these method for the future.

Any ideas on what went wrong ?
Iron temperature or maybe not ironed for long enough ?
or maybe just the wrong paper ?

I will scrub this board and try again based on any feedback here.

Thanks !

mvaughn
01-19-2005, 04:18 PM
Not bad for your first try but you will need to redo it.

I've had the best results with the cheap staples semi-gloss clay paper. Don't go with the expensive or name brand stuff, it is probably semi water resistant anyhow.

If looks as if the toner didn't have enough heat or time to work its magic. Give a little more time with the iron and move it around alot with moderate pressure. Just don't dig into the paper with the edge of the iron because it can spread out the toner underneath.

Let the paper soak for at least a half hour.

santiniuk
01-19-2005, 06:18 PM
Many thanks mvaughn.

I think your right about the paper. Had a second go and now convinced this is something I need to perfect. Taking some of your tip I let the iron move around more with more heat and a bit more pressure.

I left the paper in the water for about 20 mins but I think your right about the paper. This Kodak stuff seens to be water resistant as it does not seem to absorb the water and remains as a solid sheet even after soaking.

I used hot water this time and it certainly helped the paper separate from the copper. Again it came off as a single sheet with the image nearly 100%. Well impressed !

Not perfect but nearly. Certainly usable.

Thanks again

BobLWeiss
01-19-2005, 06:39 PM
For your first try not bad!

I would recommend pressing harder on the iron while letting it stand on each part of the paper longer. I usually set a timer for 4 minutes and iron the paper in sections and keep going back and starting over until the timer rings. As for peeling the paper, first I let it cool down so you can touch it then soak it water for at least 20 minutes then peel off what comes off easily. Resoak for another 10 minutes and then start using your thumb to rub off the remaining paper. For traces that seem to have paper between them and hole centers I use a wet eraser on the end of a pencil. Try to avoild using anything that can scratch the toner like a tooth brush..I have had it destroy boards that were fine before I attempted it.

After you etch the board use laquer thinner or acetone to remove the toner...comes right off after soaking it for about a minute or so.

Bob

MrBean
01-19-2005, 08:48 PM
Speak and ye shall receive! PICStep V3.0 is on my website. No ICSP, and status LEDs. :)

http://www.fromorbit.com/projects/picstep/

Cheers,
Alan.


Many thanks Alan. Nice job.

Once again I've altered the track sizes for better results when milling the boards. Just need to find some time to get out there and put the old Z axis driver back on the machine, so I can make a new board.

Replacement LMD's are sitting here waiting.

Thanks again, appriciated.

Regards Terry.....

Garfield2
01-19-2005, 09:51 PM
Many thanks Alan. Nice job.

Thanks Terry, if you keep giving me money I'll have to have a "Terry's Commemorative" version of the PICStep board next.. :)

It's very very very much appreciated!

Cheers,
Alan.

BobLWeiss
01-22-2005, 07:43 PM
Just an update on my machine....My X axis motor was running too hot to let it run by itself for long jobs (anything over 10 mintues) and I started to get worried about it. I am only sending 1 AMP through PICSTEP. I ordered a new motor (PacSci II) that can handle 35v, 3a bipolar per phase. I am amazed at the performance increase!! I was only getting like 11 IPM cutting rate with the other motor and this one is running at 29IPM with no problems at all. There is no heat issue and I didn't even up the amps to it yet. I am just surprised at the difference from one motor to the next...Those Pac Sci II motors are very nice and worth the money!

Bob

MrBean
01-23-2005, 10:37 AM
Hi Bob. Nice to hear you're getting some better speeds. I guess that 0.8A motor you had on X, was just too weak to get any more speed.

BobLWeiss
01-23-2005, 12:38 PM
Yeah I also just replaced my Y axis motor with a PacSci II double stack version. This one can handle 3.5 amps per phase. When running them at 1/8 step mode they are so quiet compared to the other motors. I am going to play around with the speeds this week to see what the max I can get out of them. I will back it off about 25% from that point.

How's your new picsteps working out? I was thinking of building them and placing them all in an enclosure so I can put the LED's on the front panel. Makes it easier to move around if I have to. I also put shielded cables on the motors with DIN plugs on the end instead of having them hard-wired on the PICSTEP boards.

Bob

MrBean
01-23-2005, 01:11 PM
I've not milled the new board yet. Not had the time. I'm going to put small headers in place of the LED's so that I can plug them in from a front mouted panel too.

I was also thinking about some kind of plug/socket arrangement for the motors. DIN sound ideal, plus I know we have some of those kicking around at work. Great idea. Thanks.

I hope to get the V3.0 board done over the next few days. I'll post some pictures when it's done.

Regards Terry.....

santiniuk
01-23-2005, 05:55 PM
Well the year has not kicked off as intended. We had some news about my father in law that is going to be a strain on all of us. :( This may be a longer project than expected......

It's great to pick up the tips that are posted. I'm now making toner transfer pcb's in a jiffy and cannot believe how easy it is once you get the timing correct.

The Din plugs sound an ideal method too. I'll put some of those on the list of things to purchase.

Interested to see anything you have made Bob / Terry.

I have spent a bit of time laying out what I have and seeing whats missing. I prefer building the electronics but the mechanical stuff has to be done :)

I'll post a few pics to help me explain the direction I'm heading.

The big help in this project was obtaining the Y-axis ball screw S.A - Cheers Terry :cheers:

So A few assemblies are now modelled in detail. I'll start with the easy bit...

santiniuk
01-23-2005, 05:59 PM
Well it had to be done....

I have seen a similar clamp on the forum so modified it slightly to suit my thoughts.

The Z-Axis will hold this clamp. It will hold the 43mm nose of a tool I have available.

The model of the tool is for a guide only... It's really not a banana....

santiniuk
01-23-2005, 06:02 PM
First step was to model the Y-axis ballscrew assembly I have.

Pictures and short video of it posted previously.

A few pics to show how it is made. It has a V-roller slide. Seems a shame not to use it.

santiniuk
01-23-2005, 06:05 PM
This is where the fun begins.....

I'm going to use 40mm Mk-profile Aluminium as a support frame.

This should let the Y-Axis S.A mount stable.

MrBean
01-23-2005, 06:31 PM
Looks like you're making some good progress on the CAD front. My old ballscrew never looked so good. I like the way you've intergrated it into a frame. Is nice to see some pics of how you're planning things.

Have you turned up any useful parts for X yet.... "Ratty".

Nice work and keep us posted on the design.

Regards Terry.....

santiniuk
01-24-2005, 04:51 PM
A slight change in plan :)

I never really decided on a movable gantry or movable table but finally decided to go for the gantry method.

The concept is based on using the existing base frame with a centre shelf assembly. This shelf will be the work support shelf.

The moving plate on the ball screw assembly will have a larger - sturdy plate attached that will extend the width of the base profile.

At the ends of this plate two vertical plates will rise to support the X and Z axis.

I have some linear slides that will attach to the sides of the top shelf profile that will provide support for the vertical plates.

Essentially thats about it. Need a break from the CAD so here's a few pic's to show concept of the shelf.

I realise that I'm losing some usable movement at the moment so may put the shelf end legs on the outside or ontop of the base plate.

I have not decided on how to fully fix the frames yet so will leave this until I'm happy with concept.

Afraid no swag this week Terry..... Still looking !

Cheers

mvaughn
01-24-2005, 05:37 PM
The drawings look very nice.

It seems to me that you will lose quite a bit of rigidity by only having a single track of bearings down the middle of the machine.

It would be much stiffer if you have two sets of bearings mounted with as much distance aparts as is possible.

MrBean
01-25-2005, 03:39 PM
Hi. Just a quick question on heatsinking the LMD's.

If I use one heatsink for both the LMD's on a board. Do they need insulating from each other? Or can I just bolt 'em both right on there?

Regards Terry.....

santiniuk
01-25-2005, 04:31 PM
The drawings look very nice.

It seems to me that you will lose quite a bit of rigidity by only having a single track of bearings down the middle of the machine.

It would be much stiffer if you have two sets of bearings mounted with as much distance aparts as is possible.


Totally agree, although I don't think I explained my real intention very clearly :)

Originally I thought my linear rails would mount on the side of the top shelf to run inline with the vertical gantry supports.

Another change of plan as the rails were not long enough and today I was donated a couple of slide bearing's with holders.

Shame there is only two but I'll drop them in cad and see what develops...

Garfield2
01-25-2005, 04:34 PM
Hi. Just a quick question on heatsinking the LMD's.

If I use one heatsink for both the LMD's on a board. Do they need insulating from each other? Or can I just bolt 'em both right on there?

Regards Terry.....

Hey Terry,

They're all PGND so you can tie all boards together if they share the same motor power. I've got a solid aluminium bar going across all three of my drivers, works quite well.

Alan.

MrBean
01-25-2005, 05:03 PM
Cool. Thanks. That will make life easier.

Regards Terry.....

santiniuk
01-25-2005, 05:11 PM
I'll keep rambling on... It's relaxing :)

In summary the attached pictures show the developments to date.

An extension plate 100mm wide and 13mm deep added to the existing ballscrew plate holds the two slide bearings underneath.

The bearing bore is 20mm. 20mm rod extends the length and is fixed to the inside of the frame. (Fixing detail not shown).

I'm hoping the combination of the v-roller assembly down the centre and this single bearing support on the outside is sufficient.

The gantry uprights 20mm are fixed to the extension plate and supported by a 6mm plate section on the outside.

The overall profile section does not show the full support or fixing methods as the design is still 'fluid'. This is my first project so all the guru's on here if you think I'm way off please shout up. I would rather re-cad it than rebuild !

Time for a break.

Cheers.

MrBean
01-25-2005, 05:36 PM
Looking very nice. I'd be inclined to have the uprights laid back, so when you get you Z axis and router attached, the router will still be in the centre.

Regards Terry.....

MrBean
01-25-2005, 05:47 PM
Kind of along these lines. It's even got your banana on it.

Regards Terry.....

mvaughn
01-25-2005, 06:16 PM
Another suggestion that you might consider is swapping the v-roller bearings with the 20mm rod bearings.

Put the 20mm rod bearings down the center for extra support and the v-roller bearings on the outside... that way you will have a wider footprint for the legs of your gantry and rely less on the torsion resistance of your bottom crossbrace on the gantry.

I'm assuming that none of this is already built.

santiniuk
01-26-2005, 01:52 PM
Thanks lads. Will certainly use the tip on the uprights. Seems quite a common method when I look around the gallery.

Swapping the v-roller with the bearings may be a bit too much work for me :)

It's been made by someone with far more talent than me and is quite a sturdy assembly. Maybe a last resort....

Will work on the gantry for the moment and see what turns out.

Cheers.

MrBean
01-26-2005, 06:27 PM
I really wanted to know if only one LMD on my board that shorted, had blown, or both of them. So I got out the meter and started checking outputs against one of the working boards. No difference. "That's wierd I thought". I connected the motor to the blown board. Hey presto, it fired up just fine. No problems at all. Oh well. Now I have two spare LMD's. (chair)
Looks like milling a version 3.0 board will wait a while.

Anyone know if the LMD's have internal shutdown protection? Maybe what caused it not to work after the short.

Regards Terry.....

Garfield2
01-26-2005, 06:33 PM
Anyone know if the LMD's have internal shutdown protection? Maybe what caused it not to work after the short.


Ahh yes they have quite effective internal protection. One of the datasheets show the thermal shutdown test where they short the h-bridges to ground and let it run while monitoring the output on a CRO. it looks like a sawtooth waveform as the thermal protection kicks in and slowly releases (over a few milliseconds that is), then kick in again. Pretty impressive.

I wouldn't have thought they'd survive not just a short but an overloading voltage jammed into the wrong pins. Amazing little devices it seems. Only Bob was unlucky enough to kill his, and his wasn't from abuse but taking them past red-line.

Glad to hear they're working again. :)

MORE PICS PEOPLE! :) I want to see your machines moving too!

Alan.

BobLWeiss
01-26-2005, 06:57 PM
Well I am working on a new driver setup since I will be building a new machine (bigger and different design) soon I decided to build the version 3 boards of PicStep. I just finished doing the toner transfer for all 3 boards (X, Y & Z). I will let you know how it works out when I get them etched.

Bob

santiniuk
01-29-2005, 06:12 PM
Not a lot of progress last few days but made a little update.

Basically I'm keen to spend as little as I can on this so using what bit's I have scraped together. The Origa sealed ballscrew assembly was a bit on the large side for the Z drive and a touch on the short side for the X drive. (Picture of ballscrew posted previously)

I put a quick model of it together to see where it would fit best and in the end decided to use it on the Gantry as the X-drive.

The gantry uprights have been offset based on the feedback. (At an approximate angle until everything is modelled. I will aim for a centre spidle ref to Y-Axis ballscrew plate).

So the stepper motor mounts on the inside of an upright and will be bolted in postion. A coupling from this connects to the Origa ballscrew drive shaft.

The Origa needs a standoff plate on the rear so a plate will be required for this.
(it's a shame it's not longer but will do for this model)

Still not showing all of the fixing plates and screws until things become more 'fixed'....

A few pics to go with my rambling.......

BobLWeiss
01-29-2005, 06:34 PM
That looks good! When do you think you will be ready to start putting it together? Take pictures when you do. I am getting ready to build a "bigger, better" machine next. I will start a new thread for that one. Its going to be modeled after the MDF ones that are on here now. About 30" x 20" x 6" size.

Just finished one of the new PicStep 3 boards. I have to wait for the 18 pin sockets though before I can test it out. It should be quite a light show with all the LEDs!! :)

Bob

santiniuk
01-30-2005, 10:29 AM
Thanks Bob,

Not sure when the actual building will start. I'm in a bit of a trap at the moment. The kids have taken over my garage/workshop and it's just a nightmare working in there. It doesn't help that they have a huge double seater motorised jeep in there too :)

I have just had plans approved for an external garage 27' * 13' so hopefully start that in March. I will probably leave the wife and kids and move in it ;)
A bit cold over here at the moment to make a start.

If all goes to plan the MK profile should go together easy.

I'm missing a ballscrew for the Z-axis drive but have two linear rails for it.

So... Will finish the CAD stuff soon and hope that drives me on.....

I'm also helping a friend out with the picstep drivers... Just never enough time.

Looking forward to following your thread on the new machine. Have you created anything with the old one ?

Cheers

BobLWeiss
01-30-2005, 12:15 PM
I cut out a few signs...nothing big. The machine works great and I'm going to use it for pc board work. The bigger machine I will use a router on it so I can use 1/4" bits with it. I will post some pictures of the work when I get my camera set back up..

Bob

santiniuk
01-31-2005, 05:48 PM
Well the reality that I know very little about CNC machines has kicked in :)

I'm putting together the z-Axis model using the bit's scavenged previously. The two linear rails 350mm long will attach to a backplate. A frontplate with the 43mm clamp will mount on the carriages of these rails.

This is where I need some advice. My original gantry sides have been reduced in height as they seemed huge when the z-axis bits were added.

What distance would you recommend the Z-axis backplate stands off from the cutting table ?

The image attached shows a quick mockup but the backplate is only 60mm clear of the table. Is this ok or should I raise it ?

Thanks.


(Get those pic's posted Bob !)

BobLWeiss
01-31-2005, 06:45 PM
The only problem you might encounter (like I did) with having the backplate too close to the top of the X axis table is that when you go use hold downs to keep the work from moving and they might intefere. Depends on how your holding down the work. I use T-Slots and the screws stand up about 2 1/2 inches from the table and I had to raise my backplate another inch to accomodate. Just a thought..

Bob

MrBean
01-31-2005, 07:54 PM
I would raise it as much as you can. Once you get a sacrificial cutting board on the machine, your 60mm clearance could be reduced to 40mm. My backplate clears the table by 130mm, without the sacrificial top. The main problems here are leverage forces. You may need to have the Z fully extended to reach the table, but if you have a shorter gap, you're limited to what you can cut.

When I milled my Picstep boards, I placed layers of MDF on the table top, raising it up around 3". This way I could cut the boards without the Z fully extended.

It's a bit of a trade off as to how you mount the Z. I remember trying to figure mine out. Not much fun.

Good luck.....

Regards Terry.....

santiniuk
02-04-2005, 04:59 PM
I'm still plodding away and appreciate the recommendation on raising the Backpanel.

I managed to source some Aluminium profile offcuts today at work. I previously thought it was 40mm square but this stuff is 45mm square so all the Cad work needs to be changed....

I have seen some test fixtures built with it and they seem really solid. (The central hole can be tapped)

I suspect the frame building will start next week.... :) If all goes to plan...

The cutting list for the profile is :-

Base
Ends 610mm * 2
Sides 484mm * 2
Stands 170mm * 4

Table
Ends 430mm * 2
Sides 394mm * 2

Z-Axis is almost completed..In a fashion....

santiniuk
02-07-2005, 04:35 PM
Ramble Time......

A bit of a dilema with the Z-Axis setup. I have two 350mm long linear rails and carriages that I am reluctant to cut in size. (Long term I may want to build a larger beast and these are probably one of the best components I have).

So I have made the Z-Axis with these rails and mounted the backplate 130mm from the table top. In the extreme upright position for cutting there is not a lot of distance from the stepper support and the frontplate.

I will be adding some support rails to the backplate assembly soon.

The Cutting tool is now scaled to a typical size.

I have moved the X-Axis stepper mount to the outside of the gantry uprights and made a longer coupling. (I have done this as I may have a longer ballscrew assembly available).

The one Item I am missing is a ballscrew for the Z drive. I'm really tempted to try threaded rod on this worst case. Gravity is on my side on this axis so I may get away with it....

Hopefully this should be nearing the end of CAD images as today I had the aluminium profiling cut. Sometime this week I hope to assemble it.

Ramble over.....

nuplowboy
02-07-2005, 05:01 PM
Looking Good. I'm interrested in seeing the photos of the parts going together. My second machine, already in planning phase despite the first MDF machine being about 50% done, will be mostly or all aluminum as well...

Keep it up! :banana:

ViperTX
02-07-2005, 05:20 PM
If you can an ACME screw for the Z-axis would be an excellent choice. A ballscrew would most like need a brake of some type. You could use a threaded rod...not as accurate and requires more torque to move.

santiniuk
02-08-2005, 03:52 PM
nuplowboy,

Thanks. I will post pic's as each stage progresses. I'm beginning to wish I went the MDF route now. It's a lot easier :)

ViperTX, I'll be totally honest I know nothing about what an ACME screw is but I'll search around on here for details. If they are available in the UK I may try this.

Cheers

ViperTX
02-08-2005, 05:09 PM
Next to ballscrews ACME's are the next best choice....in most instances ACME's are generally more accurate then Rolled ballscrews by a factor of 10.

kong
02-08-2005, 05:12 PM
Santini, you can get them from here - www.ondrives.com
I think they only sell to the trade, so you can just make up a business name if you don't have one. Postage is steep though, someting daft like £10. I have used the standard trapezoidal leadscrews a few times, accurate but slightly soft. This does make them easy to turn-down though!

santiniuk
02-09-2005, 05:33 PM
Thanks lads.

After a bit reading it looks like the ACME's are an attractive option.
I have a bit to get through before the Z-Axis construction starts so will hang on until the last minute before purchasing.

Cheers

santiniuk
02-09-2005, 05:43 PM
Hopefully the CAD images have not bored you all silly. I really do intend to turn this into reality and as a 'non-mechanical' type of person this allows me to makes virtual mistakes instead of costly ones !

So tonight I managed to squeeze past the kids toys in the garage and make a start.

I hit lucky with the aluminium extrusion. I scraped together enough bits that were absolutely minging. <Miinging = UK slang for filthy!>
Surprisingly a bit of degreaser and a scouring pad and it came up good as new. Perfect start.

Also a friend milled the ends for me so it's a lot better than the original hacksaw cut.

santiniuk
02-09-2005, 05:48 PM
The extrusion needs to be drilled at 20 locations. This is a 10mm drill bit and allows the extrusion to be secured together with bolts.
To save a bit of time trying to align the profile to the drill bit and to improve accuracy I made a small template out of MDF to hold the profile while it was being drilled. This proved to be a real time saver. Using a Pillar drill it was a matter of dropping onto mdf and away. No alignment each time

santiniuk
02-09-2005, 05:52 PM
The centre of the profile then needed to be tapped with a 12mm tap. This was done with a cordless drill and with the aid of a G-clamp holding the profile to the bench was quite easy.

The attached images show how the profile is assembled

santiniuk
02-09-2005, 05:54 PM
Never did find any orange capping to match the CAD stuff so ended up using good old boring black to cover the exposed joints. :)

santiniuk
02-09-2005, 06:00 PM
Finally at the end of the night the Base profile and the centre table section was assembled.

It really was quite a surprise that the centre section simply dropped into place and amazingly fitted like a glove. It feels quite solid at the moment without being fully clamped into position.

The angle brackets holding the uprights to the base are probably not needed but I will add these anyway.

The Y-Axis is now ready for bolting to the base frame but will leave this for today.

End of ramble....

BobLWeiss
02-09-2005, 06:19 PM
Looking good!!! Glad to see your in the building stage...

keep the pictures comming!! :D

santiniuk
02-10-2005, 04:04 PM
Looking good!!! Glad to see your in the building stage...

keep the pictures comming!! :D

You asked for it Bob !

I think I'm boring the pants off people now so will take a break from posting....

But a little update.

I fitted a couple of angle bracket supports to the uprights. These have made the frame rock solid. I only had two to try but now I see that they do make a difference I will fit them to the remaining 3 uprights.

They use a T fitting inside the extrusion and only take a few minutes to fit.

santiniuk
02-10-2005, 04:07 PM
The Y-Axis ballscrew assembly I have needed to be drilled in a couple of locations to allow it to fit to the base frame.

Again using T type fittings.

santiniuk
02-10-2005, 04:11 PM
And finally.

I had to loosen the table sections to fit the Ballscrew assembly.

This has clamped really well to the frame using the T fittings. Everything is just in place at the moment. I'm not fixing everything until It's progressed a bit.

With this Ballscrew fitted I can now get the extension plate made and the shafts and bearings fitted.

I need to come up with a cunning plan for alignment....

Time for a break. May be a while....

10bulls
02-11-2005, 07:28 PM
Decided I've lurked long enough, so just a quick post to say hello and thanks for keeping me inspired and informed. Nice to see some fellow UK bodgers.

I've been faffing around with CNC designs for many months, in between work and babies (sound familiar?) and have got to the stage where I'm starting to build.

Please excuse rough technicolour render (another learning curve I'm on...)

Main chassis is mostly asorted aluminium extrusions I blagged from a local company. Silver steel rails are from old dot matrix printers. Going to use threaded rods and will probably try PICStep (thank you Alan! :cheers: )

My linear bearing design is a bit dodgy. It consists of 2 pairs of skate bearings bolted to a block of steel. The bearings are spaced so they contact the rail on the small chamfer part of the bearings and prevent lateral motion. Rotating the block then bolting down should adjust out any play. These are very easy to make. I have made one test bearing block which seems like it's going to work. Biggest problem is the small contact area is going to cut a groove into my soft silver steel rods. After much deliberation I decided 'b*ger it! Like Deep thought, this machine's soul aim is to educate me and to help me make it's successor ("whose merest operational parameters
I am not worthy to calculate..")

Here is a closer view of the linear bearing blocks...oh...the skate bearings are bolted to the blue block with a spacer between each pair. Has anyone seen / tried this sort of bearing setup...I've not come across it. Could it *reallly* be that bad?!

Anyway, nuff fluff for now. I'll post some more details as they happen.
(once the laughter dies down)

Regards

Andy

Splint
02-11-2005, 08:53 PM
Hi 10Bulls,
your bearing design would probably work but I tend to think it would create excessive thrust load on the bearings. I personally would prefer to have three bearings evenly spaced around the shaft (two load bearers on top and a reaction bearing (on a concentric for adjustment) on the bottom, all with the flat area perpendicular to the surface of the rail. Your design may reduce the lifespan of the bearing and the rail.
Cheers
Splint

santiniuk
02-12-2005, 05:53 AM
Hey Andy,

Pleased you decided to join in. I was getting kind of lonely on here ;)

Anyway great to hear you have kicked the ball off, I think you have picked a good controller to build. Alan's Picstep design is how I kicked the thread off and that was enough to keep me going.

(Hey Alan are you lost in PicServo World ???)

Anyway have you built the Picstep design or just in the planning stages ?

The Images posted look good to me. You mentioned your on a learning curve on this too. What package are you using ?

One thing I have noticed is that everything commercially CNC related is so much £££ that it's enough to put you off before you start !

My skill's as a skip-rat have proved to be an asset ! I can see the light for most of the bits I need so hang on in. You will be surprised where you can scrounge stuff from. Printers seem to have a wealth of stuff to use.

I don't know enough to comment on the linear bearing design so why not try it and learn from it. Who know's it may be ok and save us a fortune.....

I need some motivation so keep going and let's see what your upto.

Cheers :cheers:

Mr.Chips
02-12-2005, 07:57 AM
10 Bulls, Nice design.
How about starting a new thread so we can watch your progress and not confuse it with Santiniuk?

Thanks

santiniuk
02-12-2005, 08:08 AM
Good Idea Mr Chips.

You may get some more feedback on your design 10bulls.

Cheers

BobLWeiss
02-12-2005, 08:35 AM
Well I got the new PicStep v3 boards completed and built. I am working on a powersupply for them now and should have test results this weekend. Its going to be a Christmas light show when they are in action. 12 different LED's blinking at once :cool:

Garfield2
02-12-2005, 08:48 AM
(Hey Alan are you lost in PicServo World ???)


Indeed I am. Still plugging away at it... :)

It's got a 32bit position register and 16bit error, P, I, D registers and can handle motor RPM above 10K easily @ 40MHz... It's gonna be a beast!

With the 32bit position register it takes my servo about 15 minutes of continuous running at it's maximum voltage (34V) at probably 6-8 thousand RPM to make the register overflow! I think that's enough resolution for anything not the size of the Queen Mary.

I'm working on the PID routines and the ramping profiles at the moment. Then I have to finish the RS-232 control port and polish up the LCD DRO display (it even has RPM!).. It's all fun!

Still hear, just busy. :)

Alan.

Garfield2
02-12-2005, 08:50 AM
Well I got the new PicStep v3 boards completed and built. I am working on a powersupply for them now and should have test results this weekend. Its going to be a Christmas light show when they are in action. 12 different LED's blinking at once :cool:

Oooo the first boards to be built and tested! :)

The design hasn't changed, I just added the LED's so it "should just work" :D

Got photo?

-A

10bulls
02-12-2005, 08:34 PM
Thanks for the encouraging words guys...I'll start a new thread with progress to date, photos, dxf etc. Sorry to hijack your thread santiniuk ;)

I'm currently 'spinning' my motors with a general purpose PIC16F84 based board I designed a few years back (pre kids), which 'plugs' into an L298N daughter board I made for robot experiments. It works OK, but the electronics aren't optimised for driving steppers. I'd much rather contribute to the 'buy Alan a lathe fund' and spend what little free time I have now chopping up metal in the garage.

I'm actually more interested in his PICServo project. I've scrounged 3 nice servos but only 2 decent steppers at the moment. I had thought to get my mill working using steppers then attempt designing a PIC based servo driver :tired:... If you need a Beta tester Alan just say the word! My Z-axis needs YOU!

santiniuk
02-12-2005, 08:45 PM
Not a problem at all Andy, It's not a hijack in the least. :)

I suspect you may get more answers to your questions on linear designs etc if you start a thread as a lot of people will think this is just the santiniuk ramble and probably have me on the block list......

It sounds like you have all the skills to jump on in. I joined Alan's Lathe fund. He must have enough to buy one now !

The Picservo Project is sounding excellent, Looking forward to seeing the details on this. Nice one Alan.

Was hoping to see Bob's lightshow posted. Any pics out there Bob ?

BobLWeiss
02-12-2005, 09:54 PM
Yeah I will be posting pictures maybe tomorrow...I need to run out and get batteries for my camera...never have enough around the house when I need them...KIDS!!!

BobLWeiss
02-13-2005, 01:53 PM
Well here are some pictures of the controller, power supply and a piece of work that I have done. Its a picture of my youngest son, came out really well..better than I would have thought.

I will take more pictures of the controller working when I hook it all up.

As you can see in the pictures, the controller I am using DIN plugs for motor connection and a LED at the top of each one for step signals. The power supply is a toridial (sp?) transformer that puts out 31vdc/18 amps.

I am also using 3 small 5vdc fans above each set of controller chips to keep them cool instead of heat sinks. These fans are 40mm size and are perfect for job.


Bob

santiniuk
02-14-2005, 03:12 PM
Well Look who's been very busy !

The new controller box looks the business. I intend to copy your idea on the DIN plugs for motor connections and will probably add a fan our two.

Do you intend not to use a heatsink at all ?

I have only operated my motors for short periods of time but certainly the heatsinks soon warmed up.

I imagine it's quite a show when all the motor's are running and the LED's are in sequence. (You beat me to the Picstep 3 construction by miles!)

That one piece of work you have created of your son is excellent. That alone is a real kick to keep this going for me. I would *love* to create something like that with my girls.

Can you give a brief summary how you created it Bob. Are you using TurboCNC still or have you moved on ?

Does it take long to cut ?

I'm hoping to see some more bit's this week...... and the next ramble.....

Thanks !

BobLWeiss
02-14-2005, 03:17 PM
Thanks for the complements..

The first picstep boards I built which I am using on my machine now have heatsinks and never get that hot, even when the machine has been running 6 hours straight! The fans should keep it under control.

I used a program called IMGTOGCODE and converted a picture to G-code and cut it out using TurboCNC. After playing around with the settings for awhile I got it down to taking about 4 hours to cut out a picture 9" x 9" in size. Once I hook up the new picsteps and power supply I should get some more IPM out of my steppers. I have them set for 20 now.

I am still trying to learn the ins and outs of CAD programs so I can design some parts for models etc...I never seem to get enough time to just play anymore...something always comes up...

How's your machine comming along? Last I saw you had the frame built correct?

Garfield2
02-17-2005, 05:01 AM
Hi guys, got some new toys!

Looks like my mill is back on the front burner again!

http://www.fromorbit.com/images/mill/Bearing_Set_tmb.jpg (http://www.fromorbit.com/images/mill/Bearing_Set.jpg)
http://www.fromorbit.com/images/mill/SK20_1_tmb.jpg (http://www.fromorbit.com/images/mill/SK20_1.jpg)
http://www.fromorbit.com/images/mill/SK20_2_tmb.jpg (http://www.fromorbit.com/images/mill/SK20_2.jpg)
http://www.fromorbit.com/images/mill/SC20UU_1_tmb.jpg (http://www.fromorbit.com/images/mill/SC20UU_1.jpg)

Click to enlarge....

Yay fun!

Alan.

santiniuk
02-18-2005, 12:46 PM
Ha !

Good to see your roughing it Alan :)

Here's me skip-ratting trying to find the holy grail for my Z-Axis and then along come your works of art ! I reckon your making too much from all these paypal donations.......

I'm looking forward to seeing your construction log. Do you intend to do one ?
What are your plans to date ? I guess you have been busy with picstep / picservo so we never really found out if this is your 1st project or not.

I see you have posted an update on your website for picservo. Looking good !

Bob /

Been a slow week, but a little productive ....

Status so far was basically frame and Y-axis fitted but should see progress again now.
I now have gantry parts so may post an update later tonight. I think I got carried away with the CAD stuff. Some of the plates were modelled from 20mm material. The bit's I have made are from 13mm and this weighs heavy..... I'm a little concerened about the weight so may do some material removal...

Cheers

BobLWeiss
02-18-2005, 12:51 PM
I just scored some 26" lead screws with nuts off Ebay so I will be getting ready to build the "new and improved" machine..I must say, the first one is working far better than I expected...I wasn't sure how well the drawer slides would hold up and they are working great. The new machine I will be making is going to be like the ones a couple people are building now on here..The MDF machines..with drill rods and bearings and a moving gantry style. I will start a new thread once I get all parts in order.

santiniuk
02-18-2005, 04:44 PM
Looking forward to following the thread Bob. You guys in the USA are so lucky. I see all sorts for sale on the USA ebay that goes quite cheap. In the UK ebay cnc stuff seems quite 'rare' and also seems to demand a good price...

Oh well. Hope your ready for the next riveting ramble.....

Here we go.....

I'm really too far into this to drop out now, even the wife is taking interest. (Actually she ask's "When is that metal thing going to move so I can get to the tumble drier ?") I just cannot wait to build my garage now. I can hardly move in there and it's getting hard cropping the pictures without showing what a mess it is :)

Back on track...

Referring to the CAD images the 4 parts making the gantry were made from some old aluminium offcuts. As mentioned this plate is all 13mm. 6mm Cap head screws are used as the fixing components.

The assembly was proved to check I was on the right track. I have not fixed solid yet.

So I present my filthy aluminium bits before and after a light scrub.

(Any tips on how to clean this stuff. Do I need to apply anything to improve the long term look ?)

santiniuk
02-18-2005, 04:47 PM
The base plate was then located onto the Y-Axis assembly plate and located with just two fixtures for testing. I will fix this with 4 more screws soon.

santiniuk
02-18-2005, 04:54 PM
So far so good.

Next step was to add the Gantry verticals. I'm quite pleased with these.

I dont have the corner angled supports yet so basically these are held in place with 3 screws per side at the moment.

santiniuk
02-18-2005, 04:56 PM
Lastly the gantry top backplate fits to the gantry arms. Again 3 caphead screws per side.

*Amazingly* the holes line up and the fixture is secured quite solid.

santiniuk
02-18-2005, 05:00 PM
In true Rolph Harris style.... 'Can you tell what it is yet ?'

I can see the light at the end of the tunnel !

Next steps are to add the two support rods and bearings that support the gantry base plate and to make the 4 angled supports that fix to the gantry base and vertical arms.

End of this weeks ramble.....

Cheers

Garfield2
02-18-2005, 05:08 PM
Ha !

Good to see your roughing it Alan :)



Indeed! When have you known me to do things by halves! :D



Here's me skip-ratting trying to find the holy grail for my Z-Axis and then along come your works of art ! I reckon your making too much from all these paypal donations.......


No, not really, I have almost enough to buy a nice big stepper motor. Or some 1/16th of a OneCNC license. I've just been cutting back on expensive lunches and working overtime. :)



I'm looking forward to seeing your construction log. Do you intend to do one ?
What are your plans to date ? I guess you have been busy with picstep / picservo so we never really found out if this is your 1st project or not.


First machine. I got all roped into the design of the motor controllers I never got around to building my machine. A tube of 25 LMD18245 imported from the USA set me back a few months of purchasing power!



I see you have posted an update on your website for picservo. Looking good !


Getting there, I'm trying to scale back a 32bit PID result integer to a 10bit PWM integer without making the whole thing to slow. Multiply is easy with the hardware multiplier, but division is hard because its just shifting and subtraction in a loop. 4 instructions to multiply, hundreds/thousands to divide! ARGH!

Oh well getting there.

Alan.

Garfield2
02-18-2005, 05:14 PM
I'm actually more interested in his PICServo project. I've scrounged 3 nice servos but only 2 decent steppers at the moment. I had thought to get my mill working using steppers then attempt designing a PIC based servo driver :tired:... If you need a Beta tester Alan just say the word! My Z-axis needs YOU!

Sure, once I complete the firmware, I'll send you a HEX file you can burn. (I'm gonna hold onto the sources for this one a little while)

Hopefully the component count should be relatively low and should use only off the shelf parts.

Alan.

Garfield2
02-18-2005, 05:17 PM
In true Rolph Harris style.... 'Can you tell what it is yet ?'


Oh dear, don't judge all Australians by Rolf f&$#ing Harris! :)



I can see the light at the end of the tunnel !


Looking awesome mate! Very well done! I cannot wait to see pictures of it cutting stuff. I'd be really interested to see PICStep running at full speed on a machine.

Cheers,
Alan.

MrBean
02-18-2005, 06:19 PM
Good skills, that man. Your machine's looking the biz now.

Nice update. Keep 'em coming.


Oh yeah. Nearly forgot. I need that ballscrew assy back now :stickpoke

Just kidding.

Regards Terry.....

santiniuk
02-21-2005, 05:49 PM
A small update.

Thanks for the word's of encouragement guys. It is appreciated.

Sorry Alan, Rolph Harris is a legend over here ;)

Terry, You have more chance winning the lottery than getting the Ballscrew assembly back !

For those of us in the UK, hope your enjoying the recent snow fall. Been ages since I remember as much as this. I managed to squeeze in building a snowman with the kids and have not warmed up since. Even with a heater running in the garage its enough to freeze the nuts of a brass monkey !
(Must google that term and find out where it came from.....)

Tonight I added the rod supports underneath the Gantry base plate. It's out of sequence to my previous posts but didn't get them cut to size and tapped until today.

The rails are 394mm * 20mm and are tapped M12 either ends.

santiniuk
02-21-2005, 05:53 PM
The gantry arms had to be removed but no problem as they were not fixed solid. The baseplate was then drilled to allow the rod bearings to bolt underneath the plate.

The bearing housings are tapped so this allowed them to be attached easily to the plate.

santiniuk
02-21-2005, 05:56 PM
Removing the top side profile allowed the rod's to slide down into position. This alignment is going to require some tuning but first impressions are quite good.

The M12 bolts will tighten into the vertical profile.

santiniuk
02-21-2005, 05:59 PM
With the large plate now back onto the smaller plate the rods are ready to be aligned and fixed.

I cannot resist turning the ballscrew coupling to move the table and its moves freely on the rods. This was the bit I was not looking forward to :)

Garfield2
02-21-2005, 05:59 PM
Sorry Alan, Rolph Harris is a legend over here ;)

Indeed, I still remember "The Goodies" episode where they're farming little Rolf Harris'es (Harrii?). Over here in Australia we barely hear of him, last time I remember it would have been 1986.

In Australia we don't drink "Fosters" and we don't listen to "Rolf Harris" and we don't all talk like "Steve Irwin".. :) The best quote I remember I heard about "Fosters" beer is, the reason we export it is because none of us will drink it!

Nice work on the mill BTW, but I just realised. It's not really a "wood router" anymore! :)

Alan.

santiniuk
02-21-2005, 06:03 PM
At the end of the night the result was better than I expected. I need to tune the rod alignment (I think) but they are really supporting the gantry base well and 1st impressions are they are running free.

I will add some form of locking method to the rails to prevent any movement.

The aluminium profile has really been a benefit.

Lastly apologies for the MDF dust on the photo's I did a job at the weekend and It's everywhere. Must have another cleanout in there.

End of Mondays ramble....

Edit /

Damn just noticed I have not fitted all corner supports yet for the uprights!
:)

MrBean
02-21-2005, 06:12 PM
Nice progress. You'll be CNC'ing stuff in no time at this rate.

Done a Google..........


The origin and true meaning of this phrase is actually totally unrelated to any form of animal or its testicles. Back in time to the period of the Napoleonic War, the great gunships of this time carried many cannons on various gun decks. As an efficient method of storage and delivery of cannon balls to the cannon for firing, a "Monkey" (this term is used to define a table and/ or a rail) made of brass was used to hold the balls. In very cold temperatures the brass would contract or even break thus allowing the cannon balls to roll off the Monkey onto the gun deck. Hence the sailors would say "it is cold enough to freeze the balls off a Brass Monkey".

MrBean
02-21-2005, 06:14 PM
(this term is used to define a table and/ or a rail)


How appropriate is that...?

lerman
02-21-2005, 08:47 PM
Nice progress. You'll be CNC'ing stuff in no time at this rate.

Done a Google..........


The origin and true meaning of this phrase is actually totally unrelated to any form of animal or its testicles. Back in time to the period of the Napoleonic War, the great gunships of this time carried many cannons on various gun decks. As an efficient method of storage and delivery of cannon balls to the cannon for firing, a "Monkey" (this term is used to define a table and/ or a rail) made of brass was used to hold the balls. In very cold temperatures the brass would contract or even break thus allowing the cannon balls to roll off the Monkey onto the gun deck. Hence the sailors would say "it is cold enough to freeze the balls off a Brass Monkey".

You don't believe everything you read on the internet do you?

My brother was the aide to the former president of Nigeria. He needs to transfer 20 million dollars out of the country. If you will send me $10,000 in cash as a show of good faith, I will split the 20 million with you... :)

Why would they use brass, when iron was so much cheaper (they didn't make cannon balls out of brass, did they)? Why not just use wood?

But it makes for a fun story.

Ken

santiniuk
02-22-2005, 08:16 AM
In Australia we don't drink "Fosters" and we don't listen to "Rolf Harris" and we don't all talk like "Steve Irwin".. :) The best quote I remember I heard about "Fosters" beer is, the reason we export it is because none of us will drink it!

Nice work on the mill BTW, but I just realised. It's not really a "wood router" anymore! :)

Alan.


Your having a laugh !!!

Your spoiling the image I have of Australian's. Surely you all drink Foster's or XXXX. You will be telling me you don't throw shrimps on the BBQ next ;)

Hmmm About the "wood router". Not sure where this thread exists. It's covered a bunch of topics now. Maybe it's a Picstep promotion thread.....

To make matters worse Ken goes and spoils a good old story.... (chair)
(It sounded good to me !)

Cheers

MrBean
02-22-2005, 11:44 AM
You don't believe everything you read on the internet do you?

My brother was the aide to the former president of Nigeria. He needs to transfer 20 million dollars out of the country. If you will send me $10,000 in cash as a show of good faith, I will split the 20 million with you... :)

Why would they use brass, when iron was so much cheaper (they didn't make cannon balls out of brass, did they)? Why not just use wood?

But it makes for a fun story.

Ken

I don't believe a lot of things........Do YOU?

It's all light hearted fun. I'm not giving a lecture on the origins of "brass monkey." It was the first page that Google turned up and I thought it was amusing.
Also, my brother's bigger than your brother and he has stolen your brothers money. So, no need to split it. Thanks anyway.
Don't come looking for us, 'cause my dad could beat your dad up.........

Back to the thread..........Sorry for my rant. Felt I was being attacked. :boxing:

All good fun this end. Just having a laugh :D

Regards

BobLWeiss
02-22-2005, 11:50 AM
I thought I was on to a good thing and was the only one who got that email message about Nigeria...damn!! Thought I could get rich quick..oh well back to work.. :rolleyes:

lerman
02-22-2005, 11:56 AM
Sorry about that Mr.Bean. I didn't mean to sound like I was attacking you. (But I can understand how you might have read it that way.)

KL

JavaDog
02-22-2005, 12:20 PM
This thread is great Santiniuk, feel free to post as many pictures as you want - you've already helped my solidify my design ideas.

I've wondered though, how do you think the 80/20 is going to be when it comes time to dial-in your machine? Has it been pretty square so far? How many feet/inches of 8020 have you used thus far?

Thanks again, and keep the great pictures flowing!

BobLWeiss
02-22-2005, 12:29 PM
Sean,

How did you get the rods to stay in place on the t-slots? It looks like you threaded the rod ends and used a bolt to go into the t-slot but how can you tighten it once in place? Shouldn't it just fall to the bottom?

Bob

JavaDog
02-22-2005, 12:36 PM
Sean,

How did you get the rods to stay in place on the t-slots? It looks like you threaded the rod ends and used a bolt to go into the t-slot but how can you tighten it once in place? Shouldn't it just fall to the bottom?

Bob

Looks to me like he drilled a hole through the 80/20 to access the screw on the rod...

MrBean
02-22-2005, 01:43 PM
Sorry about that Mr.Bean. I didn't mean to sound like I was attacking you. (But I can understand how you might have read it that way.)

KL


Thats cool. I'm here to have some fun, pick up some ideas, and help out where I can.....Made a few stuff-ups too. :wave:

Regards Terry.....

sp00k1e
02-22-2005, 04:02 PM
Why would they use brass, when iron was so much cheaper (they didn't make cannon balls out of brass, did they)? Why not just use wood?

But it makes for a fun story.

Ken

Quoting from 'Red herring and white elephants - the origins of the phrases we use every day' by Albert Jack
' The guns on 18th-century men-of-war ships needed gun powder to fire them, and this was stored in another part of the ship for safety reasons. Young boys, usually orphans, who were small enough to slip through tight spaces, carried this powder along tiny passages and galleys. Because of their agility the lads becamer known as 'powder monkeys' and by association the brass trays used to hold the cannonballs became known as the brass monkeys. These trays had 16 cannonball sized indentations that would form the base of a cannonball pyramid. Brass was used because the balls would not stick to or rust on brass as they did with iron, but the drawback was that brass contracts much faster in cold weather than iron. This meant that on severely cold days the indentations holding the lower level of cannonballs would contract, spilling the pyramid over the deck, hence 'cold enough to freeze the balls of a brass monkey'.
Anyway nice machine santiniuk
Right back out to the garage where its <STRIKE>cold enoug </STRIKE> very very cold

lerman
02-22-2005, 04:10 PM
So, I googled "coefficient of expansion of brass"... And what did I find at http://www.phrases.org.uk/meanings/96500.html


Some references say that the brass triangles that supported stacks of iron cannonballs on sailing ships were called monkeys and that in cold weather, as brass contracts more than iron, the triangles contracted sufficiently for the balls to fall off.

No one has been able to provide evidence that such devices were called monkeys, or even that they existed.

The Royal Navy records that, on their ships at least, planks with circular holes were used to store cannonballs. Also, a little geometry shows that a pyramid of balls will topple over if the base is tilted by more than 30 degrees. This movement is commonplace on sailing ships and it just isn't plausible that cannonballs were stacked this way.

If we discount all of the above and for the sake of argument assume that the contraction of a brass triangle would cause a stack of balls to fall over, science comes to the rescue again. The coefficient of expansion of brass is 0.000019; that of iron is 0.000012. If the base of the stack were one metre long the drop in temperature needed to make the 'monkey' shrink relative to the balls by a millimetre, would be around 100 degrees Celcius. It is hardly credible that amount of change would have the slightest effect. In any case in weather like that the sailors would probably have better things to think about.

I don't know what a nautical version of an urban myth is called, but whatever it is this story warrants its use.

Ken

Garfield2
02-22-2005, 05:18 PM
Your having a laugh !!!

Your spoiling the image I have of Australian's. Surely you all drink Foster's or XXXX. You will be telling me you don't throw shrimps on the BBQ next ;)


Indeed, we don't drink XXXX in NSW (horrid stuff!), but we do throw shrimps on the BBQ for xmas quite regularly. :)

And no I don't have a pet kangaroo! :rolleyes: hehe


Hmmm About the "wood router". Not sure where this thread exists. It's covered a bunch of topics now. Maybe it's a Picstep promotion thread.....

Indeed, it's really peaked the interest in PICStep I must say! But now it's gone all Navy like with cannon balls and temperature co-efficents of iron versus brass!! Where will this thread lead next!

Oh I know!

I got the first version of PICServo working last night, I've got the sore fingers to prove it! (if you don't get it, pushing around the spindle of a 31V servo motor while testing a PID loop with your thumb and forefinger is PAINFUL! :)). It all works suprisingly well, I've just gotta touch up the interface for the LCD and panel buttons and I can finally start designing the PCB! Yay!

Alan.