[JDFarmBoy]

I'm looking for some advice on sizing my motors and drivers for a CNC router that I am building. My machine consists of steel and 80/20 extrusions, with a 3'x4' capacity. My gantry will weight approximately 150 lbs. and I am utilizing 20mm linear rails and 2010 ball screws on all axis'. My plan is to use a Milwaukee 5625 router to start with and I plan to primarily cut wood and some aluminum. I was originally thinking about nema 23 570oz. motors and leadshine DM556 drivers. What are your thoughts?

[awerby]

Pay attention to the inductance of the motors. If the square root of the inductance isn't 1/32nd of the voltage you're supplying to it (or at least close) then performance at high speed (which you need for cutting wood) will be compromised. Here's a chart for a motor like you're talking about: https://www.automationtechnologiesin...100-50-4BM.pdf It has 2.5mH inductance per phase, which is pretty good for a motor that size; according to the formula above it wants about 40v to run at full speed. Your Leadshine drives can handle 50v, so the combination should work pretty well. But all motors with the same holding torque don't necessarily have the same inductance, so make sure to check that before you buy.

[repauli1]

Check out Teknic Clearpath, they are servos, with built in drive, three wire to step/directly, and two to power. Powerful also!

[ger21]

A Nema 23 570oz motor only has about 80oz of torque over 600rpm.

A 465oz Nema 34 motor will have close to 200oz of torque up to 1000 rpm.
https://www.automationtechnologiesin...-single-shaft/

I'd run it at 60V with 8060 drives.
https://www.automationtechnologiesin...iver-kl-8060e/

This will give you more than double the power of the 570oz motors.

[JDFarmBoy]

Thanks for the responses. I think I will make some design changes to accommodate the nema 34 motors. I see there are different versions of the 860 drives, is there one that's better for my application?

[JDFarmBoy]

After a short hiatus from this project I am back to figuring out my electronics. I have since modified my design to accept nema 34 motors and I think I might head in the direction of the 465 oz. motors Ger recommended. As of right now I am thinking either em806 or am882 drives, please feel free to recommend a supplier if you know of a reliable one, right now I'm looking at either ebay or aliexpress. It was recommended to run these motors at 60V but the formulas I've read around hear are pointing more towards ~42V, is there something I am missing with my calculations? Any help is appreciated!!

[Jim Dawson]

Run them at the maximum that the drive is rated for. For instance, the em806 drive is rated at 80V, so I would use a 72 to 80 volt power supply. This would give you the best motor performance.