Unit Value for PRS Standard Indexer

[jdervin]

I have a PRS Standard and am attempting to get an indexer up and running on it. The manual says that the Unit Value (VU) should be set to 16 but that is for the PRT Standard and is significantly not rotating to the proper degree. (E.g. MB,180 makes only about 1/5th of a rotation.) I found a formula in the manual, but I don't have enough information to use it. The only number I know is that the motor turns at 0.25° per step. I can't find anything telling me the gearbox ratio.

Does anyone know the proper Unit Value setting for the B-axis (indexer) of a PRS Standard?

[Brady Watson]

It sounds to me like you have a 7.2:1 motor on your indexer. If you are running a PRS - with Gecko microstepping drivers in the control box(not PRT), then your unit values will be exactly 2.5X those of a PRT. So instead of 16, your UV should be 40. Put a mark or tape on the headstock or chuck and check it to see if that is correct. I don't know off the top of my head if you have to change the multiplier value for the B axis at the bottom of the VU screen or not.

-B

[jdervin]

Yes, 40 is indeed the magic number and the multiplier value remains at 1. I used your tape suggestion and tested it at both a 360° rotation and a 3600° rotation -- in both directions. Everything was perfect. Thanks for the help.

[c_kling]

is there anyone in new england that can help with
indexer files