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.

Could you post your hal files (IE the one that uses caxis.comp and the one with the orient.comp)?

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

Thanks for taking a look.

Well, I had a good look and compared it to NoJo's config but I'm afraid I can't wrap my head around the problem.
If i understand spindle synchronized motion correctly then it really only depends on the encoder signals connected to the 'spindle.0.' pins.
I think the most likely way figure this out is to diagnose things with hal scope on the machine and find out what is happening to the index-enable signal and z-axis motion.
I'd love to help more but I have no hardware to test any of this.

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.

Another (somewhat random) thing that came to my mind is that we can also change the 'ferror' values from gcode.
That might come in handy.

Good luck.

I wonder if this could be related to the order of how the components are added in hal. I've just had a somewhat similar issue with my own encoder disconnect component and I moved the addf of my component up above 'motion-...' and it worked fine.

so maybe try to change this


to this order

@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.