Hi TrevorH,
I still have the same problem, but like you no missed steps and no errors coming up anywhere in Mach3. But, when the spindle slows more than about 5%, the "X" axis is then messed up in the next cut. Z axis is fine for me. Its 100% repeatable which makes me think it is in the coding somewhere. The solution for me is lighter cuts, with which I can then make perfect threads, even with "normal" spindle speed change.
So, I believe there are now four people posting with a similar issue with this Mach3Turn version. I still have more experiments to do when I get time and I will post them back here.
Looking through the G76 macro, I can't see how that is a problem, all it does is repeatedly call G32 and work out the correct parameters for each call. It can't make any direct X axis movement requests. So, I think there is a problem with the G32 macro with some setups.
However, others do not see this problem, esp with smoothstepper. So it could be a combination of settings or setup which then allow this error to occur.
Hmmm... Any ideas out there? No matter what the setup, the X axis should not move with a non tapering thread!
Cheers,
Woody.