Index pulses

g33 will hang if spindle-at-speed is not true
or the spindle encoder position scaling is backwards

I was missing spindle.0.speed-in

Never got M19 to work??
I don't see the signal index-enable happen with M19? I do see it with G33.1

Seems like index-enable has to happen for M19 to work. I think the signal would originate from the motion's spindle end - but isn't happening.

LinuxCNC ver 2.8.2

Yes, m19 does not affect index enable, I think for orient you need to:
1. Use the orient component
2. Have previously homed the spindle to index at some point
(setting index enable true and spinning the spindle will do)

I have it all connected (see the png above). I've done what you are talking about - it wants to unwind all the turns from after the spindle homing..

Doing a g33.1 should home the spindle.

I would say that m19 is broken as is - it should have a requirement to home and some way to ignore the full turns (what would work would be to reset position with a homing event.).

I've done more than a few searches - never saw confirmation where someone had it working? If I'm wrong - please post here.

I don't think this has anything to do with m19
(that's just a GCODE hook to start and wait for orientation)

Looking at the orient component, it basically rounds the current encoder
position-offset to an integral number of turns and then adds the orientation offset
so should never unwind/wind more than 1 turn (or 1/2 turn in mode 0)

You probably need to take a look at the orient "command" vs the encoder position
to debug this, they should never differ by more than 1 turn.

Note that they could differ by more than a turn if you started an orient operation
when the spindle was still spinning.

PCW, you may be interested, I made a modified encoder counter (with an additional register to offset the index position) for hostmot2.
This can be used for multi-start threading without offsetting the Z axis.
Modified driver only for 2.7.15, vhdl source code taken from hostmot2.zip(dated 150220).