g33 problem?

hi, I am back with another lathe spindle question.
I really appreciate the help last month I got here and have come a long way since then.
I have a 1930's Atlas/Craftsman lathe that I have put linear rails, ballscrews and stepper motors on.
Basically, I can cut threads like a dream with G76 but when I tried a G33 command, it says my spindle isn't on (red error in MDI mode or program context).

Background info: spindle speed controlled by me (treadmill motor, 5k pot).
emc version 2.4.3
Have spindle Phase A wired up to optical slot interrupter (32 tooth gear breaks the LED beam).
Also have a magnetic reed switch off treadmill setup as my spindle index...1 click per revolution.

It sort of befuddles me because this thing runs so good on a g76, I can vary the spindle speed with the pot and it will amazingly pick up the lead every time.
I thought using a g33 for feed per rev programming would be much simpler but i am error-ing out on that.
the syntax I used was G33 Z-.5 K.05 or something similar, just trying to test it out.
Any thoughts or ideas would be appreciated.
thanks:)

Hi

I think this is simply that G33 checks for a spindle motion command and speed command and does not just pick it up from the encoder.

If you enter M3 Sxxx first, even though you are setting the speed manually, it should work. does in simulation.

regards

What spindle direction are you using ? I think there was a bug if you are using ccw rotation... (M4)
oops no that was fixed in 2.4.2....

thanks for the responses, I will try the S command tomorrow so it knows spindle is on. That could be it.

Well I fried my optical switch (working on something else and dropped a wire) so had to wait for the guy to send me another one.

Anyway my problem was just trying it in MDI mode, it wasn't working like that.
I finally tried writing a program with something like this: G33 Z1 K.005 (didn't need S command) and it gave me what I was after.
Constant feed per rev no matter what the spindle speed is--pretty cool!