Acorn Lathe C-Axis+Spindle, possible?

[Measurement10]

Currently building a custom hotwire foam turning machine using centroid acorn as the controller. Does anyone have experience wiring up a spindle and C-Axis with acorn?

What hardware would be required beside the motor? Thinking of using a servo or better yet stepper since there is no reaction force from the hot-wire and the rpm is 10 or less.

Would like to have something which can switch from step/dir to 0-10v spindle control but everything i've read shows one or the other. Ideally would like to switch from Lathe mode (spindle) to C-Axis mode (mill/turn) in one program.

Open to suggestions.

[suntravel]

Look at M51 in the lathe manual.

Should work with a servo as spindle if you can switch the driver from speed to position mode. I will try this out on my current lathe build.

Uwe

[Gary Campbell]

Currently building a custom hotwire foam turning machine using centroid acorn as the controller. Does anyone have experience wiring up a spindle and C-Axis with acorn?

What hardware would be required beside the motor? Thinking of using a servo or better yet stepper since there is no reaction force from the hot-wire and the rpm is 10 or less.

Would like to have something which can switch from step/dir to 0-10v spindle control but everything i've read shows one or the other. Ideally would like to switch from Lathe mode (spindle) to C-Axis mode (mill/turn) in one program.

Open to suggestions.

What size motor are you looking for? I have a 1kw LeadShine servo, ELP drive and cables that I have successfully setup using the CNC4PC board that converts Acorn's 0-10v FWD/REV to -10v -- +10v to work as I believe you are looking for. If you are interested email: gcnc411@gmail.com
If you need, I can have it completely setup and wired with a new Acorn and Pro license

[Measurement10]

Suntravel, do you think its possible with a stepper? Cutting foam with a hot-wire so no reaction forces, with my setup i can get by with a simple 3A Nema23. I've been searching for a way to switch between Step/Dir and 0-10v but no success yet. Another option is to use the lathe in Mill Mode, disable the Y axis and use the thing as a rotary. I imagine i would need to alter the post processor.

Gary, i think that servo is a bit large for my needs but have you had luck with this setup? I might check out the lower power servos from leadshine. I do have a nema23 DMM servo here but i've heard DMM will not work well as a spindle/C-Axis because there is no way to have it lock/zero rotation- some soft of bug with DMM.

If anyone else has any guidance with using a stepper as a spindle/c-axis i would be greatful.

[Gary Campbell]

Gary, i think that servo is a bit large for my needs but have you had luck with this setup?

Yes, I have done a few of them now. A couple using relays to reverse the 0-10v polarity and better than that was using the CNC4PC adapter board

I might check out the lower power servos from leadshine.

As a LeadShine reseller, I can get you any size that you need

I do have a nema23 DMM servo here but i've heard DMM will not work well as a spindle/C-Axis because there is no way to have it lock/zero rotation- some soft of bug with DMM.

I tried using DMM a few years back, but like most here the results were not good and I got tired of sending them in for firmware upgrades. Kudos to the guys that get them to work, but I will stick with my Leadshines.

If anyone else has any guidance with using a stepper as a spindle/c-axis i would be greatful.

You are not going to find it. Stepper motors will require steps to rotate, and even if you used a pulse generator to do that, the torque at any usable speed would be too low to complete the job at hand. Use a AC motor & VFD if want the best torque solution, servo motor as second best (due mostly to rated HP) OR a servo motor with a high end drive that will do both.

[Measurement10]

Thanks Gary. Torque is a non-issue for me, hot-wire cutting foam has near zero reaction forces due to the foam vaporizing before it hits the tool. Id prefer to use a cheap stepper and perhaps switch between 0-10v and step/dir. Having said that if i don't have luck i have your email. Its good to know there are options.