Digging into the probotix.ini file I noticed the MAX_VELOCITY value for X(0) and Y(1) axes was 3.34, while that same value for the Z(2) axis was .4. Knowing my X and Y axes are limited to 200ipm on my Meteor, a little math (200/3.34=60ish) reveals these small numbers must be inches per second. I changed the MAX_VELOCITY for my Z axis to 1.0, saved the file, then ran LinuxCNC again. My Z axis now jogs and can feed up to 60ipm.

By extension, this MAX_VELOCITY value can also be changed to alter the max jog/feed speed your Probotix CNC can move in X and Y directions. Knowing the 200ipm value was chosen by Probotix to minimize thrashing of the feed rod while traveling in the Y direction, I'd keep the Y value at 3.34 (200ipm). The X feed rod is half the Y length, so I suspect faster velocities should be fine for that axis.

I've changed my Z max velocity, but haven't yet tried changing it for X. I know Probotix sets X and Y at 300ipm(5.0) for their small V90 MK2 CNC. It has 20 inches of X travel. For a Meteor or Comet with 25" of X travel 286ipm (4.77) should be just as safe. For the Nebula and Asteroid with a 37" X axis the math says 250ipm (4.17) should be fine in that direction. The Y value for the Asteroid should be safe at 286ipm.

We do a lot of fluting cuts to make tapered tenons for furniture projects. The constant up and down Z motion is where a great deal of cut time can be saved by speeding up Z velocity. I'll be changing the X velocity of the college Meteor and Nebula to these new values to potentially speed up all cuts from now on while keeping the Y value at a safe 200ipm.

4D