G33.1 synchronized tapping problem

Thanks for the troubleshooting suggestion.

Yes, same behavior, but much less Z-distance during the initial 'dive' than when using MDI.

Approximate position the Z-axis rapids to before synchronization while running a program:
G33.1 Z-0.5 K0.05 $0
(Starting at Z0.500")

• 60rpm: 0.440"
  • rapid dist: 0.060"
• 100rpm: 0.390"
  • rapid dist: 0.110"
• 200rpm: 0.370"
  • rapid dist: 0.130"
• 400rpm: 0.300"
  • rapid dist: 0.200"
• 750rpm: 0.140"
  • rapid dist: 0.360"
• 1000rpm: -0.125"
  • rapid dist: 0.625"

So perhaps 1/4 the distance vs MDI.

Still don't think this behavior is right.

Changing the Z-axis accel only slightly affected the rapid distance, if at all.

The earlier tests were done with MAX_VEL = 4, and MAX_ACCEL = 175.

Dropping down to MAX_ACCEL = 2 resulted in approximately the same pre-synch rapid distance at all speeds.

Much less violent rapids, of course.

Interesting development after more testing.

I created a new config which does not use caxis.comp to manage the spindle.  Rather, it has a (poorly tuned) orient component so the spindle can be indexed.

Running a G33.1 cycle resulted in zero pre-synch movement.  No z-axis rapid movement before the spindle 'locked' to the Z-axis.

Just smooth, synchronized movement exactly as expected at all speeds tested - including 1000rpm with a 0.050" pitch.

So now I've got a conundrum:

• Caxis.comp - allows synchronized axis movement, but tapping and (likely) threading are dodgy
  • Non-standard component, no significant troubleshooting/tuning assistance available from community
• Orient.comp - no synchronized axis movement, but tapping/threading are as desired
• Something else?
  • I'd really like a working C-axis on my lathe, but I'm rapidly losing interest experimenting with LCNC.  I want a working lathe and not a perpetual software hobby.
  • My amp can't be externally switched between position & velocity mode
  • LCNC Devs do not appear to have spindle-axis high on the list of upcoming features.

Advice welcome.

Both configs attached.  I included everything, not just HAL.

Thanks for taking a look.

Appreciate the effort.

I've had a think, and I've got one more config attempt left in me before I quit trying to have a working C-axis.

Plan is essentially what PCW suggested in my other 'freewheeling' thread.  I'm going to abandon caxis.comp, and instead use orient as a 'bridge' between velocity spindle and position-axis modes so the c-axis doesn't error out upon reconnection.

Flipping between spindle & axis will use M-codes, and I think it can be done without any halui stuff so I can do everything within the same g-code program.

I'll start a new thread when I run in to problems with this attempt.

@Aciera,

Thanks, I'll try that if it doesn't work out doing the 3-way mux2 (velocity, orient, c-axis) config.

Kinda stuck at the moment as I realized my spindle motor was a contributing problem.  Once i put a heavy chuck on the spindle it became obvious while tuning the servo that the inertia ratio was really unfavorable.

I've got a more appropriate Yaskawa motor on hand, but getting the cables, 90VDC brake converter, and shaft bushing is taking a while for everything to show up.