Orac Mach3 Z stuttering when attempting to thread cut

[johnechall]

Hi all,

My Orac on Mach3 has developed a problem when attempting to thread cut.
It has done plenty before, but now the Z axis stutters along, then comes out in X, but doesn't
return to the Z start posn, it tries to take the next pass from the end of the last one.
I've cleaned the optical readers and both LED's work ok, with one going out on the gap in the slotted disc.
Index debounce 0
Use Spindle feedback in sync mode ticked
Spindle speed averaging ticked
Here's the G code:
M00 (Put T0303 in s/cut m27 x 1.5 x 22lg)
M00
T0303
G00 X27.5
G00 Z3
G00 X27
M03 S700
M00
G76 X25.16 Z-21.9 Q2 P1.5 J0.1 L45 H0.1 I29 C0.5 B0.05 T0
G0 Z50
G0 X50
M5
M30
General turning working ok.
I'm using a PC that I have for the Triac as the Orac one has the blue screen of death,
but sure I copied everything over ok.

Any thoughts welcome.

Thanks

[angel-tech]

try putting a pause in the code after the spindle start and before the first move, something around 5 seconds. This allows the spindle to get up to speed before the code moves the axis.

[johnechall]

Thread cutting operates fine if I turn off "Use Spindle Feedback In Sync Mode",
but obviously the pitch will be ropey.
Just waiting to try another desktop to see if that solves the problem.

[johnechall]

Problem solved, G97!
Thanks for your help angel tech, greatly appreciated.