I use AMT102 encoders instead of US Digital.
https://www.digikey.com/product-deta...1307-ND/827015
The PPR can be set on the chip. They have been trouble free since installing them over 10 years ago.
Wayne Hill
I've heard that there is a little bit of delay in those AMT102 encoders... supposedly it works OK for spindle because that just results in a little bit of rotational skew of where the thread ends up; but supposedly it can cause some issues when you try to use it as the shaft encoder on a servo motor???
The AMT102 are used on the shaft of a DC motor. I do not see any delays. It runs five start acme threads reduced down 1:2 at the motor. Anti-backlash nuts. It's fast.
Wayne Hill
Hmm... well, I've actually got one here - I picked it up for testing - I guess I could rig up a stepper to it as well as a conventional optical encoder that I have here also; and see what it's actual delay is between firing the step pulse and the encoder registering it & outputting it... hmmm...
Sounds like an interesting project. Be sure to secure the cogs on the AMT102. There is a hint of backlash between the plastic cogs that could give false readings.
Wayne Hill