DIY CNC Camgrinder

basically any cylindrical grinder would be a good starting point for a retrofit of this sort i would think.

I found Andy's video


Basicallly you use external offsets which plasmac uses for torch height control and the cam grinder will follow the profile based on the angular position of the chuck. Supper simple if you know the maths behind a cam!

with a cam it's basically like any other contour you do just in a different plane in the program. all your work with plasma is done in the XY plane. with a application like this the contour of the cam is going to be done in a X/variable plane based on the configuration of the machine. so if the axis of the spindle is set up as a B axis the program would be generating the code in a XB plane rather than what you use in plasma ( XY plane)

an application like this would be a servo based machine with a fully closed loop control. this would be a good application for dual loop feedback with a 1 micron encoder or better since it is a grinding application with very close tolerances. the mechanics of the machine would have to be very tight and as close to zero backlash as possible. this would be a good example of where any kind of position comp that is end point in nature will not work at all.

probably have to synchronize the 2 axis's based on speed of the rotary axis somehow like the video you posted too. i would think it might be something linked to the arcs in the cam. probably would have to figure out a feed per revolution based on the geometry taking a guess.

cam software might have this built in if it is specialized software for this application but i don't know honestly.

interesting regardless. i don't think half a million or better for a machine build for this is in reach for most of us

Sorry, no progress to report.

Here is a nice video of an OKUMA in action.
I don't know exactly what the following accuracy requirement is, but I guess that it is less than 0.0001",,,maybe a lot less.