[samco]

we have a few compact 5 cnc with dead controls. There where some surplus pittman servos we bought a few year ago - small but had some heds 500 line encoders. Thought we could use them for something..

We mocked up a setup to see if the pitman motors where big enough. They seem to be.

-5i25 with a custom bit file that has pwm/dir on one plug and encoder counters on the other.
-pwm/dir input AMC servo drives 15 amp 80v (the servos are rated at 24v)
-cheap BOB

after hacking a config



Attachment 347528

Pretty darn happy - with that simple setup - we are getting .0002 following error. They seem to have more than enough power. (the testing was done with a 1amp 25v supply.) Currently 150ipm

sam

[samco]

Linuxcnc -> mesa 5i25 pwm -> Bob -> AMC drive -> Servo -> Encoder -> mesa 5i25 encoder counter -> Linuxcnc

I have the pwm set to 20khz

I have actually tested this setup - and others have actually run it using the printer port. You loose the high frequency pwm and its higher levels plus you have to be aware at your max encoder counting speed. But it does work.

Here is the adapter we made to go between the servo shaft an the timing gear.



Comparing the servo to the stepper

[whiteriver]

Nice job. I have a pile of those motors. They work well for all sorts of motion projects. I like em.

Donny

[samco]

just testing - proof of concept....



.00008 following error....

Attachment 347838