I have been refining my CNC machine which combines tinyG,

I have been refining my CNC machine which combines tinyG, Chilipeppr with Clearpath Servos in lieu of Steppers.

For some time Ive been trying to resolve an issue wrt to my machine loosing G54 zero. It was as if i was loosing steps, which cant happen with Servos with built in encoders.

The Clear path motor I purchased are the high resolution option of 6400 pulse per revolution.

What I concluded was that its important to do the math when configuring the tinyG and NOT exceed the maximum pulse frequency the TinyG can output. (50kHz) - long story short my Max Velocity and Max Feed rate exceeded the max pulse rate the tiny G can output. The motors werent seeing steps the tinyG couldnt output and therefore lost ground during faster moves. (This should have been more obvious to me, that I didnt have this problem when running <1x feed rate)

In order to get the clear path motors to work I had to solder in headers and pick up the Step and Direction signals prior to the stepper drivers. I had to install logic shifters to move the step/dir from 3.3vdc to 5vdc. This was a little tricky having worked this out on breadboard and now on Perfboard - Im still not entirely happy with this board and want to build a more purpose built break out board for this.

My original motivation for using the clear path servo motors was two fold.

  1. Sound level - Silent
  2. Precision

Both are amazing, however the cost and additional wiring doesnt make this a choice for everyone, but it is pretty sweet.

Im a little annoyed that one of my power supplies and my VFD have such loud fans.

I write this as a lessons learned sharing.

It would be cool to watch a video walkthrough of your setup. I’ve been fascinated by ClearPath as well, but sounds like you’ve honed using it with TinyG more than anyone.

I would also be interested in what you are doing for the logic shifting as that has been the stumbling block that i had with using TinyG and Clearpath.

Yes - I did promise you Id do that John. Ill try for this weekend.