natefoerg,
my index pulse generator is cooked
Buy a new index pusle generator, CNC4PC has one which is not very expensive or make one up from parts. I use a Halls effect sensor to get the index pulse.
Save yourself a lot of a trouble.
thread without an index pulse just "relying" on the spindle to keep in correct position
anything is possible, but, the answer on my end is NO / won't work since there is a lot more going on than you think
stepper motor on the spindle for indexing
no problem
stepper motor on the spindle for threading
servo ok, but stepper is not good ...... even bad
How can I get mach to believe that the rpm is 30 without an index pulse?
You need an index pulse in order for the threading cycle ( G32 or G76 ) to work and without it you will get an error and the program will stop .
How can Mach ever know what true rpm your running at if you never telll Mach via an input? Hope the question makes sense.
use A as the spindle and as an indexer (rotation in degrees)
Use two different configurations for the lathe one as linear ( step per unit ) and one for indexing ( angular / degrees ).
Suggest reading section 2 in Threading on The Lathe which can be found in Members Docs.
A stepper is bad for driving the spindle because as it's rpm goes up it will loose torque, the speed will not be linear as you increase it.
The speed is limited thus you wont get the spindle rpm's your after for turning work.
RICH