I'm not sure if this is the right place for this question, but I have a question about backlash compensation :

With the typical PC based G code to stepper pulse software, when the X axis has a backlash specified, how does it effect the motion of the other axis?

Example: cutting a circle with X and Y, X has backlash compensation of a small amount. As the X axis gets to the point where it will reverse direction, ( the top of the cut ) the motor stops, then does a fast move on the opposite direction to cover the backlash, then it proceeds with the 'normal' cut speed.
Fine.
But does the Y axis stop while the X axis does the compensation? It should, I think.
Also, does the axis lash compensation motion have predictable acceleration ramps and max velocity parameters to prevent motor stalls and dropped steps during the lash move?

Are all of the popular products about the same in these regards? ( Mach2, cncpro, etc ).

-Les

In turbocnc, yes the other axis pauses. There are no other settings (that I have found) to adjust the speed/time that it takes to do the compensation.

Mach2, it has a setting for backlash, but from what I read in the manual, and what I have seen when using it, it doesn't actually correct anything while cutting. The manual says something to the affect that it will compensate by trying to keep the motion goibg in one direction. I'm assuming this is for the wizards that it supplies. But the only thing I can think of that could be done like that, would be drilling holes. Someone correct me if I'm wrong please.

Not sure about any other software.

I don't think any backlash compensation works really well. They may work ok for some applications, but not all. Your best bet would be to try to reduce or eliminate the backlash on your machine.

On mach 2, when the direction on that axis changes, the axis will travel an additional amount specified in the backlash screen at a speed that is a % or rapid.

I am using it on my mill, as I have not yet upgraded to ball screws yet.

It works, although is not as good as removing backlash to start with.

Thanks ty1295 for that. I must have misunderstood the manual. Or maybe it was just an older version? Anyway thanks, once I get a new hard drive (mine went pffft) I'll have to check it out.

Early versions of TurboCNC would stop all moving axis, apply backlash to the onethat was reversing, then continue. This of cause cause stalling of an axis running at full speed, asked to stop sudenly and then restart at full speed after a pause.

Version 4 decelerates all moving axis to a stop, applies backlash to the one changng direction, then accelerates all axis back up to speed.

TurboCNC sounds like they implemented backlash the best way. Does anyone know if Kcam4 or cncpro do as good of a job? I think that this backlash feature is rather tricky to do just right.
-Les