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phillby
07-13-2005, 08:24 PM
Hello everyone,
I have nearly finished building The Jgro Router Mechanicals, a big thanks to Jgro many are indebted to you for the excellent plans. I have not been posting anything on the mechanicals as many have been there before me. However I would like to share my experiences on the Electronics. I and many others will be very greatful to Pminmo a member of CNC Zone.

http://pminmo.com/

First a few notes and maybe a question on the Mechanicals.

In Oz we have the pleasure ( or something ) of working in both Metric and Imperial. So when I choose the lead screws I used 8mm 1.25 mm pitch. The angle is similar to UNC at 60 degrees.

However all the 1/4" bolts and setscrews are BSW which has an angle of 57 degrees. Some of the tapped threads in the MDF stripped, I eventually prevented this using sanding sealer ( a very thin varnish type substance) which I used in every hole after it was threaded. I could have used CA Glue (superglue) but it is less forgiving to fingers and the like. All the # setscrews were replaced with 5mm ones. These changes were made because the original specified ones are hard to obtain. ( read expensive).

I do not have any machine shop capabilities so evey thing was cut on a tablesaw and the Dados (or rebates) were cut on a router table. Holes were drilled on a drillpress and most threads were taped using a cordless drill.

I drilled as accurately as i could mark using one piece as a template for it's twin and using each piece to position the drill for its mating surface. All this fitting was done using a pilot drill of 1/16 of an inch. I used another 1/16 drill or two to hold the piece in position while second and subsequent holes were drilled.

I did not use clearance holes on any pieces if a hole had a 1/4 bolt I drilled a 1/4" Hole.

Now my question I drilled 1/16 pilot holes for the dowell pins but have not used any as yet. My question is " what are the advantages of the dowell pins?", as I did not use accurate maching (i.e. CNC) and did not drill clearance holes. I could drill them now while assembled and this could provide more strength or not use them at all if. If some parts need more strength would it not be better to use another bolt?

Just a note the Z-Axis MDF liner bearing carrier is a different width dimension in the materials list to that shown on the detail drawing. I used the dimension in the Materials list. It works by using 3/4" long setscrews in the adjustment blocks instead of 1".

I think I have waffeled on long enough I will discuss electronics in another Post.

Brian the sawdust maker.

phillby
07-13-2005, 09:06 PM
Hi Again,

While deciding to build the CNC Router I decided to build my own electronics. I should be capable and this should save money the oniy way I can afford this project is to keep the cost to an absolute minium.

Early research suggested Unipolar was simpler as it was mostly discrete components. Seems easier than those multi-legged things especially the tiny ones with my eyes.

After a false start through insufficient research and purchasing too small stepper motors I was offered some 116 oz/in (may be from a HP Printer) Steppers. On decyphering the specs I find that the torque is

116 in Parallel Bi-polar
116 in Series Bi-polar
82 in Unipolar

There goes the Unipolar. Ok but 2.5 A is on the high side for many designs
so lets go series only half the current. But you don't get any thing for nuthing.
higher speed torque drops of quicker with a series connection. Jee I've disseminated a lot of information in six weeks since I started building this THING ( I doo luve it really ).

Ok, we have decided Parallel Bi-polar and Phil (pmino), see the first post, has many great designs. So here we go with the Allegro A3977SED single sided board. I was going to use the Opto Isolated Breakout Board but cannot find a supplier for the Opto-couplers in Oz (too hard to get them from overseas) Phil, Mouser only lists an equivalent.(Thanks). I will use the standard 4 axis BOB and use only three.

Next post I will describe again my method of toner transfer as I would like it to appear in this Build-Log.

Brian,
The Sawdust Creator.

phillby
07-13-2005, 09:14 PM
Hello again.
It took great courage to start the Laser Transfer process, of course it is difficult to source Staples paper in OZ so tried what I had. After a couple of false starts with other paper, I used Artwrite / Pelican High Gloss Everyday Photo Paper. The interesting thing is it seems to be plastic and has a transfer layer which goes sticky when water drops go on it, even when used for photos. It seems to do an excellent job better than the Blue paper produced for the original Toner Transfer which was hellishly expensive and needs a very dark thick toner layer.

There was a really good glossy toner layer left with very few places to patch up.

More on the paper the Packet has a diagram which shows 5 layers
1. The transfer layer
2. The Absorption Layer
3. The Primer
4. The Substrate
5. The Antistatic Layer.
My daughter purchased the paper 100 sheets of A4 (10"x8") for I think about $AUS 18.00 at the supermarket for her photos, I supplied the money.

The images were printed using a HP Laserjet 4050N. To iron on the image I used plain copier paper between the photo paper and the iron to prevent the plastic finish from sticking to the hot Iron. The plain paper stuck to the back of the photo paper. Beware SWMBO will not be amused if you ruin her iron.

After ironing with a lot of pressure using all sorts of technicques the flat, the tip and the edge of the iron for 3 - 5 mins., the plain paper even discoloured from scorching a little, it was of to the tap and a bowl of water. My iron was way too hot on max heat. The scorching happened even at a lower setting, maybe I could even lower the heat level some more.

After about five mins I started to peel the paper very carefully of the copper say a few millimeters (1/8 inch) at a time before soaking again for a few mins then doing a bit more until finished. Leaving the board and paper in water overnight did not make it any easier to peel of the paper (plastic). Never the less the results were still good.

A grey image was left like a very faint shadow on the paper just like the toner discoloured the sticky top layer of the paper, if there are any black specks then that part needs a toner repair (sharpie permanent marker).

I have completed two boards using this paper and technique and am very happy.

I relate all this hoping others may find similar paper and have the same success I seem to be having.

Brian
The Sawdust Creator

phillby
07-24-2005, 06:36 PM
Hi everyone,

Well I have completed the 4 axis BOB Board and tested it. Pics have been taken. I have nearly completed one of the Single Sided 3977 Boards & have been inspecting the soldering with a magnifing glass and multimeter very reguarly (my eyes are no longer as they used to be.

Question: I have read the warnings about not disconnecting the stepper motor while the Power is on, But can you test the board without the motor connected?

As I have only the final stage of testing to go before soldering in the 3977 (I am dreading the even thought of that) I really need an answer to this one. I only have 3 chips and don't know if I can obtain any more, so am being very careful.

Thanks in advance.

Brian

The Sawdust Creator.

randyf1965
07-25-2005, 06:37 PM
Yes, I used 2 led's connect anode to cathode with a 1k current limiting resistor per winding . so I had 1 set across a1-a2 and 1 set on b1-b2 when the stepper turns the light flash on and off according to the voltage being applied.... pretty cool the first time you step using a new board.

phillby
07-25-2005, 08:27 PM
Randy,

Thanks. Why 2 leds in series is that to get 1.4 Volts drop?

Let me draw in text what I think you are suggesting

Output -led+ -led+ 1KR Output

This then is connected to each pair of outputs. Which is the more positive Output 1A or 1B I assume 2A & 2B re in the same order. Sorry I am really careful. I have enough accidents which I dont think enough about so the ones I do I try to check first.

Did you limit the current on the board as well as the 1K resistor. I will be eventually setting the current limit to 2.5A as that is the rating of my Steppers. Initally when finished with testing I will set lower than this ( just to be cautious), say 1.5 A using the trimpot.

What software did you use I haven't really decided. I have the demo versions of Kellycam, Mach 2, and TurboCNC.

Unfortunately (maybe) the PC I have aquired for CNC has XP already installed not easy to remove. I have no running verions of any thing else to make a boot disk. Has anyone used Freedos to run TurboCNC?

Thanks Again

Brian

randyf1965
07-25-2005, 11:07 PM
Here is the link for the light circuit:
http://www.cnczone.com/forums/showthread.php?t=7286&page=41&pp=10

and 10bulls image from post #405 in that thread

I have used turboCNC (too old looking :tired: ) and Mach2

phillby
07-25-2005, 11:11 PM
Hi Guys,

I have been in direct contact with Phil and will sumarise so that all can have the answers. Here is his reply.

Yes it can be powered up with no motor connected. I in fact would recommend that. Do some ititial testing to make sure you have power where you should, set the current... I assume your building the single sided 3977, which version? Keep me posted on your progress, I'm always interested in each users comments. Some it goes smoothly, others not so smooth. So far I've been able to work through them all. I've been contemplating getting a batch of a smaller version of the 4 axis board and either the single sided or double sided 3977 boards made for people to buy if they want. I've not personally made the single sided board, but I may be able to get them cheap enough to sell for $6 or $7 drilled, solder mask, silk screened as well as the 4 axis board. What are your thoughts?

I then replied.

I am making the single sided board version A but removed the drill target around each hole. This to me just makes less copper. I think there is a mistake on the SS board and circuit diagram, there is no pull-up on pin 1 of the 74HC14. I noticed this when the instructions asked for checking 5V at pin 1 with it powered up and the chip in. there is 0V at this point so pins 2 & 3 are High 4.98V. I compared the circuit of the double sided board to come to this conclusion.

Which he answered

As far as the single sided not having the pullup on pin 1. It's not really a design or usage issue, although in downsizing the single sided to see about a commercial board I added it back in. It will work just fine with or without, just that I need to change the single sided document.

Yea the .2 ohms are pricey in a precision resistor, I've moved to a surface mount part that is a third the cost, and in the 2 watt package it's large enough it's not bad to solder. Second picture down, the two blue surface mounted parts with R200 on them
http://pminmo.com/gallery/2.jpg

Once again I thank Phil for his patience and help to all who ask.

I will get those Pics on tonight.

Brian.

The Sawdust Creator.

phillby
07-26-2005, 06:35 PM
Ok here are some pictures. I am elated at my achievements but not with the pictures.

1. The peeled off (plasticy) paper from the toner transfer of the Bob Board
2. The Bob Board.
3. The Driver Board.
4. Jgro's Router
5. The Router Bridge

As I said not great pictures.

Brian

The Sawdust Creator.

pminmo
07-26-2005, 07:11 PM
Looks great, keep us posted.

Phil

phillby
07-28-2005, 06:08 PM
Ok Guys,

I am about to put power on the 3977. I hope the smoke dosn't escape. I have done all checks I believe possible.

Just so I get this right for testing.
1. I have put two Jumpers on the step mode to give full step.
2. I have put a jumper on the enable Input.
3. I have put a Jumper on the direction select. ie hardware reversal points.
4. I have connected up the diodes as shown above. Post 7, Thanks Randy.

I think all that is now needed is power and step signal.

Questions:
1: Will a nine volt battery provide sufficient current for the circuit and leds?
2: will I see a single step on the leds (i.e. manual ground on the step pin)?

Thanks in advance

pminmo
07-28-2005, 07:22 PM
9V battery will be close, but should work. More the voltage than current requirements.

Phil

randyf1965
07-29-2005, 01:49 AM
I used TurboCNC when I was first testing my PicStep boards and I could pulse them with a single step and see it with the led's, the step will move from led to led with each step pulse.

You can also spin the motor with them connected and see them light up also, with NO power connected to them.

CNCRob
07-31-2005, 06:28 PM
Your router is looking great

phillby
07-31-2005, 06:38 PM
Thanks Randy & Phil,
Well its Monday morning and I'm happy but sad.

The tests were fine only one set of leds would light. The other output was a dry joint, or should I say Open circuit at the 3977 pin( not quite enough solder I was sure I checked every pins continuity to the board, guess I did all but that one).

Ok so the motor moves when I short the step to ground for each pulse and the other way when I change the hardware reversing link. Great! By the way I have a 24V squillion Amp Power Supply connected now. The motor is locked when the power is on, as it should be I hope. Holding torque and all that.

Now its time to connect up the computer and BOB Board (hurriedly make and check some ribbon Cables. Connect a short jumper from ground to the aux enable pin on the BOB. Load up Mach2 and read and read and read somemore. Check through the settup and decide limit switches are not needed at this stage as the motor is sitting on my desk. Check that the emergency stop works to the program when a permanet jumper is connected from L to pin Ten on the Parallel Port. Short out Emg Stop, Yes OK.

I used Mach2 because the only PC I have is an XP machine. Verrrrrrrrrrry Detailed Instruction Manual.

Ok so we will jog the motor.
BA BOW. It don't work.

I can still pulse the motor from grounding pin 2 of the Parallel Port while it is connected. The computer has 3.46V on this pin when power is off to the BOB and Driver. When Power is onto these it goes up to 4.96V.

I think all this points to Mach2 but don't know where to go from here. I think I have set it up correctly but who knows? I tried using the y-axis same result. I have only built one driver board at this stage.

Help

pminmo
07-31-2005, 08:38 PM
Couple of things. Did you setup pin 1 (enable) on the interface board? Leaving it open the drivers are disabled. Did you setup Mach2 outputs to correspond to the interface card? i.e. correct LPT port, Pin 2 = X step, pin 3 =x dir....

Phil

p.s. Now that I think about it is Mach2 usable with Windows XP without a special PPort driver?

phillby
07-31-2005, 09:45 PM
Hi Phil,

Yes I grounded the pin just behind the connector on BOB. The motor will step if I ground pin 2 on the P/Port with all power on and IDC cables in place.

Mach 2 supposedly takes over the Computer similar to a virus (sort of ) and can redirect the program away from the XP services. I think this is what happens. Yes the Step and Direction pins are 2,3,4,5,6 & 7 for X,Y & Z this was the default Config i found but I did check it.

Thanks,
Any other Ideas. :drowning:

Anyone

pminmo
07-31-2005, 10:15 PM
Setup the logic probe on the 4 axis interface. If you have the driver board hooked up as the x axis, with the interface connected to the pc, jog the x axis and monitor (on the 4 axis board) pin 2 of the db25, then pin 3 of the db25 to see that you are getting signals from the pc. pin 3 should reverse state when you tell mach 2 to jog one way then the other. If you are getting step pulses the brightness of the probe LED will vary in intensity. By probing a ground line it will be off, by probing a 5vdc power line it will be full on. While jogging, it will be somewhere in between in brightness.

phillby
08-01-2005, 07:26 PM
Hi All,

Well I thought I knew what I was doing.

Let's just work on the BOB Board so a disaster does not smoke the 3977. Yes the direction pin for each axis did change eventually when I plugged the BOB Board in instead of the printer( it was not that way the night before but I needed to print and the USB configuration wasn't the default, (it is now). But I could see no action on the step pins. I read and re-read the setting up of Mach2. The logic probe was off on each axis before a step command then it stayed on until the computer was powered down.

At this point it all seemed too hard.

Many people seem to use and love TurboCNC I had downloaded an exe file that created a DOS Bootdisk on a floppy along with TurboCNC. Maybe it was time to try to do it this way. XP you know.

TurboCNC is running lets see if we can workout how to configure it. It's default used active hi Steps so I changed this on the X-axis( I still only have one Driver Board made-up. Same results. Lets try the Y-axis when it is jogged the led doesn't come on. Oh yes it does, if you turn off the fluro Magy-lamp.

What's different between the X & Y-axis. Oh the step pin is set wrongly to Active high on the y-axis. I wonder if I change the X-axis if it behaves the same. Yes!!!! Ok so we will connect the driver board, it works too.

:idea: I wonder if Mach2 is the same. It is, It is.

Question If I short the pin to ground and the motor steps why do the programs need Active hi to control the motor?

Well now I am happy :p to build the other 2 driver boards. I think I will tin them with tinning solution first. The soldering on the other board was woefull as I left the toner on and melted it of while soldering, not pretty.

CNCrob Thanks for the compliment

Cheers

pminmo
08-01-2005, 08:08 PM
Hi All,


Question If I short the pin to ground and the motor steps why do the programs need Active hi to control the motor?

Cheers

When you are shorting a pin to ground you are creating a hi to lo, lo to high transition. One step , its that transition that it works on, not a steady hi or low level. Enable and direction on the other hand are steady states.

Glad to here things are progressing. Tinning is a nasty step, but provides really nice results. Keep us posted.

Phil

phillby
08-03-2005, 07:53 AM
Well I said I was going to tin the other two driver boards which I have now done, but I took some photos after doing the first. A bandsaw and disk sander on a lathe do a great job of cutting a PC board to size.

The pictures once again do not really show the stark difference between copper and tin, but tinned boards give a much nicer soldered finish when the components are added.

I am concerned about the 3977 and the heat it generates. I can only hold my finger on it for a few seconds. Approx 35 years ago the Plant Chief Electrical Engineer when inspecting a very high powered motor said if you can only hold your hand on a machine for about 10 sec then it was about 110 degrees. Of course as an apprentice I was suitably impressed.

Anyway what to do about the 3977, as it is mouted under the board it may be porely ventilated. I believe I can attach a heatsink with a special heatsink glue but I may also have to mount the board vertically and install a fan.

What's everyone think? (group)

pminmo
08-03-2005, 05:11 PM
Brian,
The best way to heat sink a 3977SED is via the ground pins. There are two holes labeled GND15 and GND16 just off to the side of the SED. What I have done is to take a piece of brass flat and drill two holes in the brass flat to correspond to those two grounds. With some heat sink compound I lay the brass flat over the SED so that the holes line up with those on the ground (i.e. sandwich the SED between the pcb and brass flat). I solder two wires in the brass flat then pull those through GND16 and GND15. In that arrangement, you pull heat from the copper pins as well as the plastic package. The 3977 does have an internal thermal shutdown if that makes you more comfortable. Keep me posted.

spalm
08-04-2005, 12:39 AM
The government FDA suggests that you should keep your water heater below 120 degrees so it will not harm small children. I have always used this as a spec when monitoring controller boards or power supplies at work.

Buy a cheap digital “indoor - outdoor“ thermometer that has a probe and tape this probe to your hot spots. Now you have something you can measure and quantify your changes. Most of them will even record the max temperature obtained. Stay below 120.

Fans work wonders if things are not too stressed. You can use one from an old PC or Radio Shack with a little wall mount transformer. Heat sinks with compound are universally used. Don’t get too hung up on shape or gel or glue, just do it.

Steve

phillby
08-04-2005, 06:35 PM
Thanks Phil & Steve,

I have mounted a heatsink on the 3977 as described by Phil and while it has improved things I think I will enlarge it and maybe use old PC Heatsinks. I will measure the temp and be advised by what I find. My garage can reach 40 C (104 F)or more in the Aussie Summer. It was -2 C (28 F)this morning.

I will continue with the other two drivers now. I can't wait to get this puppy working. I think of something new to make with it all the time.

Well as Phil says "Too many interests, too many projects, not enough time".

Cheers

phillby
08-14-2005, 07:00 PM
Well I finally completed the other two boards.

Tradgedy of errors. I have found that the tip in my Weller Soldering Station despite discolouring all the time was not really hot enough, a No 6 Tip. I put on an old and pitted No 7 and the solder melts instantly. I filed it to a finer point and even found it was copper. I had thought the newer one was something else because apart from the instant when it was tinned and wiped it never looked tinned.

I built both other boards and checked them all out before installing the 3977s, now the moment of truth. The second board checked out and ran fine, "Beaudy". The third board was less co-operative. I thought it all checked out but there was 20V on all output legs. I checked and checked some more I couldn't see what was wrong.

I came to to the conclusion that some A B checking between a good board and the faulty one may be the way to go. To help I phoned a mate who agreed to come round. We started from scratch, the pulses were getting through the 74HC14 as I had earlier tested. Mate said is there something wrong with enable, "No". Is there something wrong with Reset? "Bugger it's shorted to ground." We scratched around the tracks lifted the capacitor, it's still shorted. It must be under the 3977, It was we couldn't see it but by removing some solder with a bit of solder wick it came good.

Ok, one of the led's from the earlier test jig is now on but the computer won't control it. Oh my, it helps if it the parallel port is plugged in.

Thanks Ricci. I now have three working Driver boards.

pminmo
08-14-2005, 08:54 PM
Brian,
Great news. Must say I love your writing style. I'm smiling ear to ear.... Been there doen that!

FYI, I just ordered a number of a variant (took advantage of commerical pcb capabilities) of the single sided boards to sell to those who don't relish the thrill of toner transfer. Also a 4 axis interface variant. Probably the biggest downside of doing the toner transfer is the lack of solder mask on the 3977SED socket. These boards are FR4, solder mask silk screened boards from an ISO 9001 production house.

Phil

phillby
08-30-2005, 08:41 AM
I have been very busy.

I am going on holidays from "the land down under" to where we stole the America's Cup from. While I am there I will present a good friend with the goodies shown below. The darker wood is Blue Gum and the lighter one is Silky Oak. A kit was bought consisting of the board and the bases and heads of the pieces. All I had to do was turn the bodies on my wood lathe " Oh so easy? Not !!!" My turning skills and speed leave a lot to be desired. Even sanding and polishing each piece took about 20 mins each.

Oh well it's done now and I am very proud of them. I leave for the States on Thursday and will be away for 18 days. "What no Zone for 18 days. How will I catch up on everyone's Build Logs and the Open Source Design."

:) All is not lost I have arranged to have 9' of 1/2 10 Acme Thread delivered to a friend together with some couplers and a 1/4" to 1/8" Collet for my router.
I also intend visiting Woodcraft and Roclear in Phoenix. I hope to get a tennoning Jig for my table saw.

Keep postig and I will try to catch up a d get back to my router Build when I get back.

damae
08-30-2005, 01:27 PM
Good work with the exotic woods!
Enjoy your visit to the states; we look forward to a big update from you when you return! =)

phillby
10-10-2005, 09:05 PM
The Holiday is over the States and the people were great and the big Finn loved his Chess Set.

I visited Woodcraft in San Francisco and Phoenix Spending $150.00 on wood working bits and pieces the main Items were a Tennoning jig for my tablesaw and and some diamond tiped bits to try in the CNC router when it is up and running. I also collected from Phoemix a 1/4 to 1/8 router collet, 9ft of Acme Rod & 8 Nuts from a friend who had pre-ordered them for me. I visited Home Depot in Honalulu spending more money the major item was a Freud Dado set again for the table saw. Swmbo was not very impressed with the extra luggage but accepted I had saved heaps ( I didn't point out I had spent heaps.

Now back to the real world CNC Building. Is it real?

I have been working on mounting the lead screws and Stepper Motors since I got back. I was not impresssed with the leadscrew longitudinal axis movement that was present with a single bearing in my brilliant design (silly me). I didn't realise there is sideways movement and this is why everyone talks about preloading bearings.

Since then I have taken what I have read on the Forums especially Spalm's Build Log and come up with the drawn system for supporting 8mm threaded rod in skate bearings. I will later post a picture of the motor mounting that was incorpotated in the hold down bolts for the delrin.

Two bearings were used so that preload could take the leadscrew longitudinal axis movement out.

Sorry about the Metric measurements but 5/8 is approximately 16mm and 7/8 is approximatly 22mm. I used forsner type bits and they were Imperial measurements. I cheated with the drawing.

I am still in the process of installing this. I belive on the other end I will use one bearing and clamp it to the MDF with the recessed Delrin and maybe let the rod float in the bearing. 8mm rod 8mm bearing. Or if it helps with whip control use lock nuts to place the rod in tension.

WEEEEEE!!!!!!! we are again achieving something.

djastram
10-13-2005, 08:23 AM
Looks like a project I just finished up last spring. Looks good.

triticale
10-13-2005, 11:48 AM
Commenting on the first post in this thread, I have a tip regarding CA adhesive. Acetone is an effective solvent for freeing stuck fingers; for commercial Superglue nail polish remover works but after working with Easman 910 I now keep the straight solvent handy.

phillby
10-30-2005, 04:18 PM
I have engraved two things the girl sitting on her haunches and a name plate 400 X 70 mm quite happy with the results but have struck a problem.

I am trying to put a border around the engraved sign. very simple rectangle with filleted corners.

I drew it in Autocad and imported the DXF into Mach 2 which made the G-code however it won't run the code. When it is run it progresses along a straight side and when it gets to the radius it gives the message

"Mon - 07:56:35 ---Radius to end of arc differs from radius to start on Line number #10"

I have looked in the G-code section of the Mach 2 Manual and as far as little o'le me can see the code seems OK. Can any one help Please.

The DXF and the G-Code is attached

damae
10-30-2005, 04:55 PM
Perhaps the lines aren't trimmed exactly to each other. Or you could have a case of duplicate lines on top of each other?

phillby
10-30-2005, 05:10 PM
Thanks for the comment but I created this dxf on a different computer and generated and tested the Gcode just so I could post it. I get the same results as I got at home.
As I say the Gcode generates fine. It just won't display and run properly in MACH 2 which generated it.

phillby
10-30-2005, 09:11 PM
I found the Answer.

In the configuration Menu

Initial State Settings

There is a check-box for IJ Mode Absolute or INC Absolute fixed it.


Thanks

phillby
10-31-2005, 05:11 PM
Here are the pictures to complement the earlier post.
It is so hard to get away from the CNC to organize the uploading of the pictures as I need to do it from home.

Rodm1954
11-04-2005, 10:37 AM
Hi Brian,

A practical solution to mounting the motor and axis. It might be a bit of trouble posting pictures but they do make it easier to understand how things go together.

One suggestion might be to move one of the clamps through 180 degrees to balance the weight on the shaft.

My first post on the CNC forum. :)

cheers,
Rod

phillby
11-07-2005, 06:54 AM
I have not mounted the electronics in an enclosure yet. So they are in what used to be called breadboard style, (sitting on chipboard), They do work though. Thanks Phil.

I made HDPE Adjuster blocks for the long Axis. Black looks dont it.

I also had the leadscrew (alright, Allthread, Binding because the hole didnt line-up. A skateboard bearing held captive with locknuts and one of the old adjusting blocks fixed that.

phillby
11-07-2005, 07:11 AM
The first pic is of my dust collection system, Electrical conduit shaped to get near the router bit not berry efficient but better than none.

The bandsawn pine mounting clamp can be seen. It works well. The original MDF ones were never completed as the split whils't drilling.

I read on another forum that an oilstone box was more or less a rite of passage for apprentices.

I have had an oilstone for thirty- five years without a box it now hase one.

phillby
11-07-2005, 07:31 AM
Here are the pretty pictures.

pminmo
11-07-2005, 04:44 PM
Brian,
AWSOME!!!!!! I know you were a little concerned about your soldering skills and the 3977, was it easier than you thought?

joecnc2006
11-07-2005, 04:52 PM
What power supply are you using?

Joe

phillby
11-07-2005, 04:58 PM
It wasn't my skills 40 years as a hobbiest and engineer it's my eyes and the small distance between the tracks. As I posted earlier the No 6 weller soldering tip that although new was C R A P when replaced with a No 7 that I had to file to get rid of pits that held half a reel of solder worked much better.

The solder wick that cleared out the short which was under the chip was a godsend (that is also what I was scared of).

Maybe my biggest problem was I new what could go wrong.

All's good now.

phillby
11-07-2005, 05:59 PM
Joe

It is a 24v Switchmode given to me by a friend it was used in display lighting in cigarette counters.

It has an adjustable voltage up to about 31 volts when it automatically shuts down I am running it at about 30V

Sorry I can't help you build one or tell you how to get one

Cheers

Brian

tauscnc
11-07-2005, 07:18 PM
Hey Brian,

Great job on the machine. I remember my first cut was in balsa and I have it today. Looks great! Good work.

taus
www.cuttingedgecnc.com

phillby
02-08-2006, 05:43 PM
Long time no write.
Appart from the distractions of the season and a SWMBO who allthough she doesn't stop me keeps finding things I must do first, I have been doing things on the machine but it dont show.

It was woefully out of alignment, as it had all been just put together to make it work. The main problem apart from slightly out of square was the seeming binding of the y-axis slightly and x-axis more so to the point of stalling. I thought that the line-up would cure all this. You know the leadscrew (allthread) not sitting parallel with the liner rails(OK, OK, Pipe!!) linear rails not parallel and co-planer, all that. How should I stop the sag in the Y-axis rails.

phillby
02-08-2006, 06:08 PM
The method I came up with was replace the top of the bottom torsion box using 3/4 MDF and take it out under the rails to level with some 3/4 Sides with a dado in them to support the extension. this makes a pretty solid platform. Watch the spacing to the bottom of the gantry. I then put a spacer and shims to take the sag out of the rails. To stop spread I used a bolt head adjusted in from the t-nut locked in the new sides. This all made for a better aligned machine along with more HDPE adjusters on the X-axis as the more you play with the MDF the more trouble that is encountered.

Well, yes it was necessary to fix all this but NO It Didn't Fix the stalling stepper Problems.

Bugger what next?

phillby
02-08-2006, 06:33 PM
I know I'll replace the stepper motors with larger ones. I am using 115 Oz inch ones What about say 270 or 280. $US39.00 sounds good in theory but with postage for 3 $AUS 236.00 is less attractive I can get them locally for $262.00 also unattractive, but I may have to bite the bullet.

There has always been slight crunching sounds when runing the machine, is it from rough rails and the bearings being amplified by the torsion boxes or something. Can't see anything obvious.

Well last night I took the x-axis motor off and held it in my hand and it still has slight crunching sounds guess it's not the linear rails and skate bearings at all. Funny that. It also will stall in one direction under no load reguarly but intermittently. Methinks it's not the linear bearings but the motor bearings.

I read somewhere on a manufactures or dealers web site yesterday not to disassemble a stepper mottor, but I don't know why and I don't have any choice. I can toss it in the bin before I try to replace the bearings or after if it doesn't work. Can any one comment on this.

All the motors may be a bit dodgey as thay each make similar sounds but not as bad. O'well they were free. However it may be much cheaper to use what I have and replace the bearings rather than buy the above motors.

posix
02-08-2006, 06:49 PM
open the motors, there are two little springy washers that push against the lid and the bearing. take them out, clean them thoroughly, take the bearing out, spray some wd40 on it you'll be amazed how free(er) it will run. if you've got some lube apply to the bearing if not it doesn't matter. while you're "in there" check the condition of wires, see if any need soldering. put everything back together and voila - you got yourself a free-er and smoother running stepper!

pminmo
02-08-2006, 06:50 PM
resonance?

spalm
02-08-2006, 11:55 PM
Just re-read this thread and realized that there are no pics of the entire machine. Could you post some and maybe we will spot something?

Steve

phillby
02-09-2006, 05:01 PM
The Rotor is out very carefully, not very easy even though after removing the circlips it just pushes out. The stator is totally enclosed and the screws are too hard to shift so I will not be getting at any solder joints. I had let a mixture of turps and oil (so it was very thin) soak into the bearing while I was running it in my hand, when I was testing it for the last postings.

BTW sealed bearings do let oil in if anyone needs to lubricate some bearings the light oil was in the w-cli[ps at the other end when I pulled it appart. The Shaft end bearing was cactus and I have a request in to a Bearing supplier for 3 new bearings. The opposite end bearings are perfect.

The bearing supply man is a friend who I hope will deliver the bearings to me at the Golf Club tonight. I then only have to get the bearing off. I do not relish the job as there is less than 1mm gap, so no room for the jaws of a bearing puller.

These things are sent to try us. (now I'm showing my age)

phillby
02-14-2006, 05:34 AM
Steve
I took a few pictures of the Router over the weekend.

The one of the cutting bed also shows the Plywood sides that I put on for strength

The Corner shot shows the base extension meeting the sides of course the Dado os not obvious,

The out of focus shot of pipe shows the adjustment bolt and teenut and the shimmed spacer block underneath. Imagination and good eyes maybe necessary.

The other shows the variable speed 1/4" Trimming Router $49.99 Aus = $US35.

phillby
02-14-2006, 05:50 AM
I have replaced the bearings on the X-axis and although it certainly needed it the stalling although better continued.

I swapped the Z and X axis motors and was able to run at 425mm / min without missing steps the stalling was only evident at much higher rates.

I think I will get the larger motors. Just shy of spendihg that much.

I wanted to produce a sign for SWMBO to get some brownie points. Started a couple of weeks ago with Sheetcam not realising the limit on number of lines of code for trial version. Ended up using 10Bulls CAMBAM.

Steep learning curve but I made it Thanks 10Bulls.

Ok Don't go all mushy it's Valentines Day. I only finished it an hour ago.

Some steps were lost when the cutout was done as the rest of the sign had shifted within the cut outline mostly along the Y-axis about 2 MM. I fixed it by sanding it. It's about a foot square.

I know I change between units reguarly but I was here (actually I was born here) when Aust converted to Metric so am nearly more comfortable in estimating and visualising in Imperial even though I run in Metric. Measuring and division by 10's is much easier. I use the Imperial on the zone because I think the majority of zone members are based in the US, although the majority may only be small.

Well The Machine is getting there slowly, I'm still having fun so bring on the challenges only don't make em to hard or expensive. A simple sign won't pacify SwMBO for too long if I spend too much.

pminmo
02-14-2006, 04:56 PM
Brian,
What machine control software are you running?

phillby
02-14-2006, 05:52 PM
Phil
Mach 2

I think you might be right about the resonance, The bit I read said it happens but didn't offer any solutions.

Brian

posix
02-14-2006, 07:22 PM
I think there is only one solution and it is called "gecko" :)

esmiller
02-15-2006, 12:22 AM
What size is that sign?

Any chance of you posting the G-Code for it?

TIA .. Eddie

(p.s.. personally, i was trying to do an engraving of my wife & her sister for a Valentines Day present.. guess I was too ambitious for a beginning project.. especially for a first try with the re-built machine.. Well, that plus misjudging the speeds for the bits.. brok ALL of my .010,.020, AND .040 size bits.. going to a store in nashville Thurs that sells the 50pack of bits that is offered through Harbor Freight.. Nice thing about the store is you get to SEE & CHOOSE the pack of bits you want.. YEA !! Now I just have to hope they have them in stock !!

BTw.. if anybody is interested, here is the link to these bits on the website..

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=34640


I have replaced the bearings on the X-axis and although it certainly needed it the stalling although better continued.

I swapped the Z and X axis motors and was able to run at 425mm / min without missing steps the stalling was only evident at much higher rates.

I think I will get the larger motors. Just shy of spendihg that much.

I wanted to produce a sign for SWMBO to get some brownie points. Started a couple of weeks ago with Sheetcam not realising the limit on number of lines of code for trial version. Ended up using 10Bulls CAMBAM.

Steep learning curve but I made it Thanks 10Bulls.

Ok Don't go all mushy it's Valentines Day. I only finished it an hour ago.

Some steps were lost when the cutout was done as the rest of the sign had shifted within the cut outline mostly along the Y-axis about 2 MM. I fixed it by sanding it. It's about a foot square.

I know I change between units reguarly but I was here (actually I was born here) when Aust converted to Metric so am nearly more comfortable in estimating and visualising in Imperial even though I run in Metric. Measuring and division by 10's is much easier. I use the Imperial on the zone because I think the majority of zone members are based in the US, although the majority may only be small.

Well The Machine is getting there slowly, I'm still having fun so bring on the challenges only don't make em to hard or expensive. A simple sign won't pacify SwMBO for too long if I spend too much.

pminmo
02-15-2006, 06:37 PM
Goto 1/4 or 1/8 step sizes and see if it has an effect.

HayTay
02-15-2006, 07:39 PM
Have you tried using Mach3, instead of Mach2? Mach3 seemed to work much better with my setup (Xylotex 3 axis unipolar driver board & HP LaserJet II/III unipolar stepper motors).

The downside with switching to Mach3 is you have to go through the configuration all over again. The interface, while similar, also takes a little time to get used to.

Give it a try if you have the time and as long as you don't have some other reason (hardware wise) not to.

HayTay

phillby
02-15-2006, 10:16 PM
Eddie,
I can an will post the Gcode. I have already posted the DXF and the Cambam File in 10Bulls thread on Cambam which is here
http://www.cnczone.com/forums/showthread.php?p=136808#post136808
I do not have access to the code at present and I used a 4mm straight bit.
BTW I have asked Harbour Freight the cost of shipping to Australia.

Phil,
I will try 1/4. I am using 1/8 step at the moment.

Hay Tay,
Laziness is why I havn't tried Mach 3 as I knew the setup is different.

Thanks

HayTay
02-15-2006, 11:03 PM
In Oz we have the pleasure ( or something ) of working in both Metric and Imperial. So when I choose the lead screws I used 8mm 1.25 mm pitch. The angle is similar to UNC at 60 degrees.

Phillby,

I looked at your first post in this thread (shown above) for your leadscrew specs. I'm not as good with the metric to imperial conversion. I got the 8mm is approx. 11/32" but what does the 1.25mm pitch convert to in threads per ????.

After playing around with my JGRO build using the stock 1/4"-20 leadscrews specified in the drawings I finally settled on configuring my driver board for 1/2 step mode. It seemed to be the best balance between torque, speed, accuracy, and consistency. The smaller the step size, the more steps, and the greater the chance of lost steps. As the number of steps increases the time between the steps decreases possibly resulting in less distinct steps (two or more steps may be interpreted as one).

I'm currently working on changing my leadscrews over to 1/2"-10 ACME threaded rod using a bearing setup like yours and switching from cable made from hookup wire and duct tape purchased from the local auto parts store to manufactured shielded cable. Don't laugh, no project is complete without duct tape! (check out Duct Tape Guys.com (http://www.ducttapeguys.com/) if you need a laugh!)

Just my observations,

HayTay

phillby
02-16-2006, 04:31 PM
Hay Tay,
There are 25.4 mm/inch so a pitch of 1.25 is 20.32 threads per inch. Very close to the 20 of 1/4 but the diameter is very close to 5/16. The Jgro plans call for 5/16 bolts to go into the 8mm bearings which are a pretty reasonable fit. I just used 8mm.

Eddie,
Here is the Gcode file.

phillby
02-20-2006, 07:26 AM
Hay Tay,

I tried 1/4 and 1/2 Step mpde tonight and was able to crank up the speed to 350mm / min without loosing steps using 1/2 step mode I don't think 1/4 was any better than 1/8.
I will test some more tomorrow night and see what speed I can achieve without loss of steps.

Eddie,

The shipping cost of the $6.99 bits to Australia was $53.00 US. I guess Harbour Freight are destined to keep their bits as far as I'm concerned. They wont ship by first class mail as it cannot be insured. I am working on getting motors and maybe these bits via a friend in the States. We'll see.

Gotta go, It's late over here.

Rodm1954
02-20-2006, 08:42 AM
Brian

I went down the same path you are going. Reducing the step mode from 1/8 to 1/2 or 1/4 also improved my speed but it made the router real clunky particularly on small radius circles and arcs. I changed it back to 1/8 step in the end because I didn't like the noises it was making, however, it wasn't loosing steps and you didn't see any loss in resolution either.

On the weekend I swapped out my 10 TPI acme with delrin nut for a rolled ballscrew from HomeshopCNC. My speed increased from 750mm/minute to 1800mm/min. I kicked this back to 1200mm/minute for a safety margin and I can put my full weight on the axis while it is moving and it just keeps on chugging along. For our Imperial friends this is ~47 inches/minute cutting speed. I have a heavy aluminum gantry so I am very happy with this figure.

My limited experience tells me that these motors die at higher revs and the only way to crank up the cutting speed is to increase (or is that decrease?) the pitch of the leadscrew to take advantage of their low down torque.

pminmo
02-20-2006, 05:12 PM
All the curves I have seen start seriously dropping off at 800 to 1200 hz step rate. Seems like most of the hobbiest machines are based on threaded rod that typically is 10TPI or higher. Thus they want more RPM's. Been there done that...........

phillby
02-20-2006, 05:22 PM
Thanks for the comments Rod. I may have to use that 10 TPI Acme thread I have been putting of using as it will be hard for a doit youselfer to turn the end down for the bearings.

Rodm1954
02-21-2006, 10:32 AM
Brian
I am happy to turn the ends for you if you want to pay postage or have another way of getting it to Perth and back.

phillby
02-21-2006, 04:30 PM
Thanks,
For the offer Rod I could possibly get them to Perth, but will try a former work collegue who runs a machine shop I now authorise payment for many of the jobs he does for the company I work for, so he Knows I help him get prompt payment.

The pitty is I have a wood lathe and was able to centre another project up in a four jaw chuck last night but then couldn't see how I could accurately hold a cutting tool to do the job.

Maybe I should have invested in metalworking machinery instead of woodworking. Maybe both. ssssshhhhh SWMBO might hear and kill me. Agahhhhhhhhhhh.

Rodm1954
02-21-2006, 07:23 PM
Brian
Always good to have a mate in the business.

phillby
06-14-2006, 07:04 PM
I bought 3 x 425 oz inch motors from this site.

http://www.kelinginc.net/SMotorstock.html

I'm as happy as a pig in S*1t.

I had them shipped to Australia ( a bit dear $US 68.00 but that's the freight cost not what he's adding) all up it cost $Aus 303.00 for the three, quite reasonable when it was going to cost $260.00 for 279 oz inch motors from Advanced Automation In Australia.

The motors arrived within a week (not bad service from the other side of the world). I have been busy so only connected them up last night. They seem to have a fan running in them I guess to cool them. It sounded a little like a frying sound but I can feel air comming out the connections slot.

I am still testing but have doubled the speed so far to 500 mm per min. The 1/2 inch 10 acme should double that again which will be 1m per min or say 40" per min. for a slightly modified Jgro. We'll see.

Greolt
06-16-2006, 09:37 PM
The shipping cost of the $6.99 bits to Australia was $53.00 US. I guess Harbour Freight are destined to keep their bits as far as I'm concerned.
Brian
Look at this ebay store http://stores.ebay.com.au/ONE-PASSircuit-Store
50 drills for $17.95USD and only $13USD shipping. They come in specific sizes too not just pot luck as from HF

A few ebay sellers offering similar but these seem to be the cheapest.

By the way did you get a 1/4" to 1/8" sleeve to put them in your router? If so where did you get it?

Greolt

crocky
01-02-2007, 05:07 AM
Hi phillby,

I am about to make a start on a CNC Router and was wondering where you got the pipe from?

Which part of the country do you live in?

Questions.....
Bob
Hoppers Crossing


Ok here are some pictures. I am elated at my achievements but not with the pictures.

4. Jgro's Router
5. The Router Bridge

As I said not great pictures.

Brian

phillby
01-02-2007, 04:08 PM
Hi Bob,

I live in Sydney at Quaker's Hill, (near Blacktown). I purchased the Black Pipe from Easy Metal in Blacktown. I believe from other research that the following may be sources to try,

ALL grades of steel at The Steel Store, Marayong,

Emco, Rawson street Auburn for all sorts of stuff.

Aus Scrap 2B Gladstone St Newtown for scrap Metals

Where do you live. If in Sydney you may like to visit. I have had too much on my plate to do much with the (read anything) CNC. It is however a going concern and it only needs me to be inspired to create something or need something that needs to be made on A CNC.

Cheers

Brian

crocky
01-03-2007, 02:37 AM
Hi Brian,

I'm at Hoppers Crossing, West Melbourne so I would have to drive for a while before I could visit you :) thanks for the offer though.

Thanks for the info on the pipes. You had better be careful saying that you need something to do, I could think of heaps to do :)

flyboy1015
01-03-2007, 04:32 PM
Hi Brian,

Just thinking about building my own hobby CNC. I like the drive you built. I have been looking at building this one: http://www.dakeng.com/hardware.html because I have most of the parts for it. I have some surplus steppers that I thought I'd try with it before building the entire machine. Don't want to get to the end and not have it work!!! Anyway, I was wondering what driver design you're using. I like the LED idea. Any advice?

Chad

flyboy1015
01-04-2007, 12:30 PM
Hi Brian,

I'm getting pretty close to building my own CNC. I've been thinking about building my own drive like the one here: http://www.dakeng.com/u2.html What are your thoughts, experience, recommendations? I want to first gain confidence with a drive and motors before beginning the rest of the CNC. What drive are you using for yours? I really like the LED idea for verifying the signal. Very cool.

Chad

flyboy1015
01-05-2007, 04:05 PM
Sorry for the multiple posts. Didn't realize that it may take a day or two to show up.