View Full Version : CNC Router Drive system Recomendations?


cdsgraphic
01-10-2007, 11:38 AM
I'm building the Solsylva router and would appreciate any reccomendations for the drive system (controller and steppers). This is a budget machine so I'm not going to be getting anything expensive like a gecko controller.

I was looking at the xylotex kit with the 269 oz/in motors, but now I'm not sure if this is the best way to go. I see a lot of talk about the PS and board not supplying enough power to the motors.

Now I'm thinking about a HobbyCNC board and my own home-brew PS, but what steppers would be a good match with the rest of the machine?

The plans do have reccomendations but I am upgrading the design from 5/16 x 18tpi threaded rod to 1/2 x 10tpi acme threads hoping this will give a little more speed. The materials that I will be cutting would include wood, mdf, plywood, HDU Foam Board and maybe the occasional plastic.

It was pointed out to me that from the HCNC board a 280 oz/in stepper would actually result in about 200 oz/in but a 425 oz/in would be about 300 oz/in. But as I understand it, the bigger motor loses torque as it runs faster. Would this be an issue for me or should I stay with the smaller stepper?

Sorry for the long winded post, just a newb looking for the all the info I can get.

Thanks,
Trevor

ger21
01-10-2007, 07:51 PM
It was pointed out to me that from the HCNC board a 280 oz/in stepper would actually result in about 200 oz/in but a 425 oz/in would be about 300 oz/in.

Not necessarily. Only if your using 8 wire motors. A 300 oz-in 6 wire motor is still a 300 oz-in motor when using a HobbyCNC. But 8 wire bipolar rated motors will lose about 30% of their toruqe when driven with a unipolar drive.


But as I understand it, the bigger motor loses torque as it runs faster. Would this be an issue for me or should I stay with the smaller stepper?


While that's true when you go from Nema 23 motors to Nema 34 and 42 motors, just because a motor has more torque than another doesn't necessarily mean the torque will drp off faster. Current and voltage ratings (and inductance) are more important factors. Ideally, you should look at a torque chart for the motors to compare them.

GaryCorlew
01-10-2007, 08:51 PM
I have a xylotex and I like it very much, I have never had any problems with it and it was very easy to hook up. I looked at hobby cnc, but I did not go with that because I had no experience with soldering electronics which concerned me very much.

CnoEvil
01-10-2007, 09:21 PM
Hey Gary, what are the specifics of the machine that you built? Got any pics or a build log?

Thanks,
Mark

GaryCorlew
01-11-2007, 06:03 PM
It will cut a 24" x 48" sheet The frame is made from 80/20 aluminum extrusions .631 ball screws linear rails and bearings, Xylotex board and a
cnc4pc multifunction board. I did not do a build log, I work two jobs six days a week I barely had time to even build it. There is one picture in my gallery of it just before I completed it. I have attached pics of my current project. It is an ATC for my lathe.

cdsgraphic
01-12-2007, 10:00 AM
Thank for the info guys! That is very helpful. :D

Trevor