Additional Pseudo Axis

On a CNC lathe with servo spindle control, has anyone experimented with machining stock into non-cylindrical shapes by running the spindle at slow rpm's and moving the x-axis in/out as a function of spindle angular position. Are there any CAM programs that support such a feature?

I agree that it would require a spindle with high torque and fast and accurate x-axis movement.

Of course one can do a little with offsetting a part in a 4-jaw independant chuck, but the above concept has a lot more flexibility.

At work the Mazak I feed and push the button on stops rotating and moves in/out on the Z axis to broach a keyway inside of a bore. I don't see any reason why you couldn't do the same with the X axis, but I'm not a programmer...

EMC2 has spindle synced motion that theoretically could do that. I don't think anyone has tried it yet. It would be a neat experiment.

http://www.linuxcnc.org/docs/2.2/htm...e-Synchronized

you would be breaking the motion into short x moves per partial revs.

a relatively high count spindle encoder imho.

This is a pretty complicated spindle synced motion gcode program.
http://jmkasunich.com/cgi-bin/blosxo...k/fusee-1.html
[ame="http://www.youtube.com/watch?v=ACvRilmIKDQ"]YouTube - Variable Diameter/Variable Pitch ThreadCutting with EMC2[/ame]

sam