[mekanofreak]

Hi, I'm new to this forum, so if its the wrong section, excuse me.

I'm building a small cnc machine (20" by 25") using stepper motor and a psu salvageg from an old printer, the motor are unipolar motor (5 wire) and the psu has two output, one 12 volt and one 40 volt. The transformer on the psu is rated 15 amp. I build a small cuircuit using a couple of uln2003 I had lying around from old scanner and tested the motor using turbocnc using the 12 volt output of the psu. The motor where able to move the machine rater easily but the uln2003 would just die and literally go up in flame (and I mean literally, like in "poof" gone) after about 1 or 2 minute of operation, sometime less. I know thats because the amperage is too high on the psu but that was just for a test to see if the motor worked on the machine.

I did some research to find a suitable driver for my machine and found 2 that look like they would work. Money is an issue and I dont want to spend too mutch on driver since its only for a small project ( if it work great, maybe I will eventually invest more and build a bigger one, but not for now ). So, here are the two driver I found, one from hobbyCNC :
http://www.hobbycnc.com/products/hob...er-board-kits/
And those one from probotix :
http://www.probotix.com/stepper_moto...ers/ProboStep/
That need to be conected with that:
http://www.probotix.com/breakout_boards/pbx-2/

So, for a small project like that, should I go with the cheaper one form hobyCNC, or the one from probotix ? And would they work alright with the psu I salvaged from the printer ? If not, I also have a 24v 12amp psu I made from 2 computer power suply a while ago that work great. So, what do you think

[mekanofreak]

no one ?

[CNC Bill]

Hi, I bought the 3 axis Hobby Pro kit.
It wasn't too bad to put together after I looked up a good soldering guide. I used a 36V 9.7A power supply. It worked on the bench for several test runs using Mach 3, then it just quit after 15 to 20 min into a test run.
Here is what I learned:
1. Don't go over 24V
2. It's very easy to break, lol.
3. You get what you pay for
4. You can't push this board without problems.
Maybe I will fix it ($45 plus sh)for 3 driver chips, but it is sitting in a drawer now.

I got a great deal on ebay for 4 Parker E-AC drives and motors. Brand new drives and 550oz motors for under $400, or 15% of retail!
I just got my homemade mill up and running last week, it's so sweet seeing it work!
Good Luck

[mekanofreak]

Guess I'm gona go with the hobbyCNC kit ( soldering not really a problem for me ), yes its cheaper ( I dont intent to buy 400 $ worth of parts since this is just an experiment and I got all other parts for free ) but from what I gathered in other post it should do the job since my motor dont draw that mutch amp. Will a 24v 12amp psu work with a hobbycnc or is it too mutch ? I also learned on this forum that not putting heatsink on the driver ship on hobbycnc kit is a bad idea since they overheat, is that true in all case or just for the big stepper motor ?

sorry for all the question, kinda new to this.