Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Marshall on March 22, 2017, 01:06:09 AM

Title: Oval holes
Post by: Marshall on March 22, 2017, 01:06:09 AM
Hi, my plasma is cutting oval holes, why? the x and y axis speeds are the same, I also calibrated my machine twice and still have the same problem. I also changed the speed in motor tuning with no change, accept that my cut sizes where either to big or to small. please can someone tell me what to do. 
Title: Re: Oval holes
Post by: joeaverage on March 22, 2017, 02:39:30 AM
what units do you use?

Mark the current location of the torch. Zero X, move X some reasonable distance, say 200mm or 8in in the X axis only
G0 X8.

Now move it back
G0 X0.

If it does not return to the same position the fix that, no useful work can be done otherwise. Once you are happy that X is moving
the nominated distance do the same thing with the Y axis.
If you wish to cut an 8 inch circle then the X axis must be able to travel 8 inch, not 7.5 or 8.5 but 8. Likewise Y must be able to move
8 inch on command otherwise the circle will not be round.
Fix each axis independently to be accurate first then cutting circles is a doddle.