Posted this on another website-lotta views, no replies-cant believe I'm the only one that's had this problem.


Star SRIII Swiss Machine HEAD2
This weekend I ran a program like this:
1.Bore
2.Internal thread
3.Retrace with boring bar to remove burrs(copy and pasted previous bore)

Boring and threading run fine.
When I go to retrace the boring bar path, the z-axis is about .012 off from the first path!

I went through the program with a fine-toothed comb, looking for G10's or G50's, etc.-found nothing.
I was using G92 threading cycle, switched to G76-same results.
I gave the retrace path a different offset-same results.
I ran the program and jumped the threading cycle and found that the 2 boring paths lined-up perfectly this time.
Problem must be with threading cycle.

Threading cycle was programmed fine.
The problem turns out to be the rapid moves within the threading cycle are causing the next tool(or the ZB pos. of subspindle) to momentarily lose position.
We turned the rapid over ride knob down to 25% and have not had a bad part since.Turn it up to 100% and the next part is bad.


Just thought I'd share this and see if anyone else has had a similar problem