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Mister H
01-07-2007, 02:51 PM
I already started a thread but now I see that it is in the wrong section (http://www.cnczone.com/forums/showthread.php?t=30066), my appologies.

So now in the right place ;)

I have recently started designing my first CNC machine
The dimensions the cutter can reach are about 90cm x 70cm x 10cm

As for the linear bearing I use the following parts:
20mm steel rod for the x and y shafts. for the x axis I will support this rod in the middle to prevent bending.
the bearing itself consists out of 2 bended (120 degree) plates (4mm thick) welded on a plate for fixture. on these plates i connect some bearings (6 on every side)

for the Y axis i'm not sure weather I'll use a sliding bearing or the same bearing as described above.

The z-bearing is a sliding bearing on a 15mm shaft.

I already bought 3 1.7Nm steppers and for the drivercard i'm building the PICstep at the moment. I have some trouble finding a shop that sells the IC DIGIKEY LMD18245T-ND for a reasonable price over here in Holland. I can order them at digikey, but i don't know if i have to pay taxes and importing costs etc. Does anybody know where to find them in europe?

every comment on the design is welcome since i'm not sure weather the design is stiff enough.

Many thanks

Hendrik

[edit] added a picture of the linear bearing i want to make

bp092
01-07-2007, 07:24 PM
what did you model that in?

joecnc2006
01-07-2007, 07:39 PM
On you bearing slides, what are you going to use to prevent the Gantry from lifting up?

Madclicker
01-07-2007, 10:38 PM
On you bearing slides, what are you going to use to prevent the Gantry from lifting up?

120 degrees will wrap the pipe.

svenakela
01-08-2007, 03:39 AM
I already started a thread but now I see that it is in the wrong section (http://www.cnczone.com/forums/showthread.php?t=30066), my appologies.


Hendrik,
I moved your other thread from the engineering forum to one of the DIY forum. At least a little bit better place for the thread. :)

Regards,
Sven, moderator

Mister H
01-08-2007, 06:11 AM
Hendrik,
I moved your other thread from the engineering forum to one of the DIY forum. At least a little bit better place for the thread. :)

Regards,
Sven, moderator

Thanks, i couldn't figure out how to do it myself.

@bp092, I modelled it in Solidworks and rendered it to make it more realistic.

What is everybody's opinion about my Y-axis. Should I go for the home made bearings or the sliding bearing. The advantage of the home made bearing is that I can make a construction to support the rods.

Brunow
01-08-2007, 06:55 AM
Zeer mooi begin. :) Wegens dat je van nederland bent ken je toevallig http://www.mijncnc.web-log.nl/ zijn mannen die ook al een tijdje bezig zijn.

Nice start! Where did you buy those steppers?

joecnc2006
01-08-2007, 08:50 AM
120 degrees will wrap the pipe.

Oops, you are right, don't know what i was thinking, guess we all slip sometimes.. lol

Rance
01-09-2007, 01:47 PM
Hendrik, All looks well, except as has been mentioned before with stiffening the gantry sides. how do you plan on building your bearings (Post #1 last pic)? Welding?

Mister H
01-09-2007, 03:32 PM
Hendrik, All looks well, except as has been mentioned before with stiffening the gantry sides. how do you plan on building your bearings (Post #1 last pic)? Welding?

yes I''m going to weld this. maybe I have to put some reinforcement ribs in it

Mister H
01-09-2007, 05:04 PM
so what do you guys think about this set-up for tha gantry (it is just a principle sketch, it isn't completed, no place for z-axis yet!!)

And would you go for 20 or 30 mm rods?

Guldberg
01-09-2007, 05:17 PM
If they are supported like that, 20mm will do, proberly less if you like or a hollow pipe. The solsylva has proven that concept

Mister H
01-09-2007, 05:27 PM
Ok, now i'll have to make a choice... make everything from 20mm or 30mm rods. the rods on the gantry can be 20mm, as Guldberg already suggested. But what about the rods carrying the gantry. i think they have to be 30mm to be able to carry everything without bending to much. Or maybe i will have to support them like this as well.

For me the major disadvantages are the construction. How to make a round profile on the mdf where the rod can be glued / or whatever on.

Greetings Hendrik

PS: somebody has an idea where you can buy the LMD18245T for the PICstep in europe for a normal price?

dan dimock
01-10-2007, 05:11 AM
Keep up the good work, sure is looking nice - I am working on the computer end now, trying to learn it, soon I will be ready to start building my unit, if you have plans, I may copy yours, best of luck
Dan

Mister H
01-10-2007, 05:14 PM
I've got the PCB's for the stepper ready now. Got almost all the parts for the stepper drivers... so next time i've got some spare time... its soldering time :D

I still have to make the interface board. Which interface board (with break out) do you think is ok to make?

I also got the parts to make the bearings, so i can make them as well. Havn't got time to make some photo's now. but will do that next week (i'm not home until then so building is paused as wel :( )

Hendrik

vger
01-11-2007, 06:18 PM
As you mentioned early on, you intend to support the rods near the center. Take a look at the end on view of one of your bearings with the rod in place. 20 mm will do. At the bottom there is sufficient room to support the rod along it's entire length. Perhaps to a piece of flat bar on edge or angle or T extrusion. Not welded, but epoxy, or even screws all the way up from the bottom into tapped holes in the round bar. The end view would look like a lolly pop. One other thing you will have to deal with is a means of adjusting the bearings so they are in contact without too much load on them. Maybe an offset shoulder bolt going through the bearing? Took me a minute to find it again... http://www.buildyouridea.com/cnc/hblb/hblb.html might look familiar. Keep up the good work. :)

jmytyk
01-19-2007, 04:26 AM
nice renderings, what software are you using? i noticed you even changed the textures on the edges. is the 'blotchy-ness' due to trying to cut your render times? -- man do i need to brush up my cg skills.

nevermind- just saw you say it's solid works...

Mister H
01-19-2007, 06:12 AM
I rendered it in Solidworks yes. I didn't do anything with the edges, just applied material to it (I applied somehing that looked a little like MDF) and rendered it. Solidwork did the rest.

Mister H
01-29-2007, 03:14 PM
I've been busy with the electronics and I've got the PICsteps ready (except for the LMD's). I have also chosen a interface (4 axis pminmo) where I already bought the parts for.
So now i'm back to the mechanical parts again. The spindels have arrived today (tr14x4 and hexagonal nuts).

As for the linear guiding... has anyone of you tried a concept like the included drawing? And if so, does it work ok or what are the drawbacks?

thanks in advance for the info

Mister H
02-03-2007, 09:31 AM
some photo's of the parts I've bought and made.
The electronics aren't completely ready yet (still waiting for the LMD's to arrive). The spindels are tr14x4 spindels and the steppers are 1.7Nm from stappenmotor.nl

Mister H
02-14-2007, 02:09 AM
i have redesigned my design after checking all the designs on cnczone.
What are your comments and which design do you prefer?
I hope to start building this weekend :D

I used multiple designs from this zone as an example and I hope that I my use there designs.

dan dimock
02-14-2007, 04:45 AM
What size are you planing on making you machine? And why the 2 pipes on the side, It looks to me like that would just add problems.

I would add adjustments blocks on the end, if I was going to use Two.

I am building one using the new plans from Lion Claw, and I went to a one and 1/4 in solid bar for my X rails ( I had them on hand ) and added the blocks, they are out of metal, I am hoping that this will help when I get to that point.

This is just my idea, as I do not have all the wood-working equipment to build one and make sure it will fit that close.

Good luck, keep us posted on how it goes.

Dan

joecnc2006
02-14-2007, 08:47 AM
i have redesigned my design after checking all the designs on cnczone.
What are your comments and which design do you prefer?
I hope to start building this weekend :D

I used multiple designs from this zone as an example and I hope that I my use there designs.

Does look familiar, Why don't you just use my drawings and save time in reinventing it. and just mod the files you need to that way you know it is a proven machine and everything will line up perfect for you. I have them for everyone to use for personal use.

You will need adjustment bearing blocks on the X and Y axis.

Joe

Mister H
02-15-2007, 06:28 AM
You will need adjustment bearing blocks on the X and Y axis.

Joe

Joe,

do you mean adjustment to adjust te tension/alignment of the angleprofile (and the bearings) according to the steel rod, or adjustments to be able to adjust the position of the steel rod?

joecnc2006
02-15-2007, 07:41 AM
Joe,

do you mean adjustment to adjust te tension/alignment of the angleprofile (and the bearings) according to the steel rod, or adjustments to be able to adjust the position of the steel rod?

Bolts to adjust the Bearing blocks to the Pipe Rails.

Here is a link to the files you can download and also see the machine in 3D, use solid works free e-drawings viewer.

In the picture Note the 4 Bolts on the side of the Gantry.

http://www.lumenlab.com/~joe2000chevy/CNC_Model_2006_R-1/

Joe

Menno
02-18-2007, 05:46 PM
some photo's of the parts I've bought and made.
The electronics aren't completely ready yet (still waiting for the LMD's to arrive). The spindels are tr14x4 spindels and the steppers are 1.7Nm from stappenmotor.nl

Nice project! just one question,
where did you get the Tr14x4 spindles from? (I'm from the Netherlands too)

Mister H
02-19-2007, 06:28 AM
I bought the spindels at overtoom.nl. The only thing that is different is that tr14 normally has a 3mm travel/turn and this one has 4 (not a standard type)
(http://www.overtoom.nl/bedrijfsterrein-werkplaats/aandrijftechniek_c_4418.html)

I didn't had much time as I had hoped, but still the building has started now :D

plans: cutting the mdf-board to the right size according to my drawings

picture 1: the sloths in the sides

Picture 2: copying the shape to the other side

Picture 3: 1 side almost done

Picture 4 the y-axis put together without nails/glue etc. talking about a nice fit :D

Then my time was out so I couldn't cut the openings in the y-axis any more.

Mister H
03-05-2007, 06:07 AM
I'm back from a 10-day holiday and I hope to be able to continue building soon.

I've got a electronics question. If you for example have a power suply that is arrangable from 0-30V and max 10A. can you easily modify the output voltage to for example 15-45V and about 10A?

erikkate
03-05-2007, 08:20 AM
I'm back from a 10-day holiday and I hope to be able to continue building soon.

I've got a electronics question. If you for example have a power suply that is arrangable from 0-30V and max 10A. can you easily modify the output voltage to for example 15-45V and about 10A?

That's not what i would recommend, I would go for a big transformer, a rectifier and a simple capacitorbank, this would be sufficient. Big transformers are easy to find around look at 'de kringloop', or at auction sites in Holland like marktplaats.nl. Using / Misusing a arrangable power supply is not the way to me.

Looking good though! Ga zo door!

Mister H
03-23-2007, 07:24 AM
So the building continues...

Last week I continued with the Y-axis. The y-ax torsion box is almost finished (photo's will follow soon). Tomorrow I hope to be able to completely finish the Y and the the z-axis partly and to start with the x-axis.

I was thinking about the electronics since I received the LMD's last week (thanks rené :D ). How much Ampere is going trough the wire bridges of the PICstep from allan? I didn't think about it when I built it and used some thin wire (0.15mm). but if all of the max. of 3A goes trough it, I should use about 0.5mm2 I think? I want the drivers to be able to give the maximum current of 3A. Anybody who knows the answer?

Thanks in advance and I will post the photo's soon...

Mister H
10-23-2007, 04:39 PM
So.. Í'm sorry for not continuing the build report.
I have been very busy with the electronics and getting them to work.
It hasnt succeded though :( The transformator is working as is the interface card. The PICsteps are giving me a headake.

Meanwhile the buiolding of the machine has continued as well.
I finished the x and y axis. except for the spindles.

Some extra info:

The x-axis uses vertical plates on which the angle iron with the bearings are mounted. Thes vertical plates are fixed in 2 directions by the surrounding plates. I can adjust the position and angle by the bolts on the outside.
The y-axis uses the same principle.

I think that i'm gonna use sliding bearings for the z-axis.

Í also have a topic on Pminmo's site concerning my problems with the PICstep.
If somebody could help me I would really appreciate it.
John (from Pminmo) is already helping me as well, but more people know more ay;)

I can't give a direct link atm since john is changing webhosts and the board is down.

Mister H
10-23-2007, 04:47 PM
and some more pictures...

I like my Makita machines.. :D

Mister H
01-08-2008, 06:25 AM
Hello fellow engineers/machinists,

The building lies on it's back atm, since I've got some problems with the electronics.

In this thread the problems can be read:
http://www.cnczone.com/forums/showthread.php?t=45801

At the moment the motor can turn both directions, but i still have troubles getting everything to work properly. The One thing i'm not sure about is the force of the motor as well as the low-speed steps.
When i joggle the motor with high speed then i can't stop the motor by hand(it is to strong), but when it stands stil and i put my finger just against the shaft (not even holding it) and i joggle, then it can't start and keeps on the same place jumping 1 step forward and the backward again.
I think this has to do something with the software settings.

Who can give me/help me with the settings for the following situation:

-I'm planning to cut wood with it.
-the spindle is 14x4 trapezium (4mm per revolution of the spindle)
-max speed???
-max acceleration??
- motor is the following:1.7Nm, 200steps/rev
http://www.stappenmotor.nl/Datasheets/ShiMotoren/23SM%20F%20serie.pdf
-i'm planning to use 1/8th step. ( so probably 1/4x8x200=400steps per revolution?)

Mister H
01-17-2008, 06:56 AM
Hmmz, not much response yet.
I'll post it in the software section.

This is how i'm planning on connecting the stepper to the spindle.
It is this complicated since the stepper has a 10mm shaft and the core diameter of the Tr14x4 is a little smaller so I can't just connect it.

The idea is that i place a thread M8 on the end of the spindle.
On this thread I place a connectionpiece with M8 hole in it, which I lock with a M8 nut. This way I can place a big enough bearing on it. the bearing I fix with a washer and a M16 nut. The end of the connection piece is 10mm again so the flexible coupling fits on it and connects the spindle with the stepper.
I have to drill holes (not drawn) in the bearing housing in order to be able to fix the flexible coupling.

Any comments /suggestions /remarks?

joecnc2006
01-17-2008, 02:53 PM
not sure why you need it so complicated, just connect lead screw directly to motor shaft with the coupler you have shown

Mister H
01-18-2008, 03:50 AM
The reason why it is so complicated is since the core diameter of the trapezium thread is smaller than the diameter of the coupling. In order to be able to place the bearing right I have to have a straight,smooth shaft (smaller than the core diameter of the thread), but then I can't use the coupling any more since it is to big then.

Gr.

jerber
01-18-2008, 05:43 AM
Can't you use a bigger bearing, with an ID of 14mm, and "lock" it with two trapezium nuts ?

I think that if you turn the Tr14 down to 10mm there's enough "flesh" to clamp on.
There are also couplings with different ID's on either side.

Mister H
01-18-2008, 06:17 AM
I have tried to put a bearing on it with 10mm ID, but they are also small, so it didn't align well (I could feel/see it wiggle when I turned the spindle).

The other idea might work, but that way I'll lose to much length of the spindle, and I'm not sure whether it will allign properly since the nuts do have play as well.

joecnc2006
01-18-2008, 07:54 AM
normally what people have done, is have a bearing that fits the threads, and can use something similar to dumpsters threaded clamps to lock it to the bearing, then us a coupler on the motor the shaft bore size on one end, and the lead screw bore size on the other end.

Joe

bp092
01-18-2008, 06:18 PM
whats the diameter of the threaded screw? not at the base but the screw itself? that looks overly complicated as joe says and if it's only a little less than standard sizes thats what set screws are for..

on a side note with all respect is there any particular reason you are trying to re-invent the wheel here and use joe's 06 design in yours, seems a lot of the choices you went with I wouldn't have and I think it is more work than it's worth. I've always liked the simple way the nema steppers connect with love joys and a flange bearing mount to stabilize it. Anything more than that on a diy MDF router is overkill imo.