I am doing a lathe conversion that uses a sensor-less vector drive to control the speed of the spindle. I have a index pulse as well as a multi-slotted disk (60 slots per revolution). I know that index is needed for the start on threading however I want higher resolution on the rpm sense. I there any way to use both the index and the 60 slotted disk for higher resolution rpm at very low spindle speeds? Also is constant surface speed working in mach turn? Haven't tried it yet but figured I would ask if there are issues.

Use of a multi slotted disc is no longer functional and was called Timing and should not be enabled. The single index provides rpm in real time
and is quite accurate. How slow are you talking about as the dro only reads to an even integer, but i have commanded my indexer to turn at things like 1/2 or 1 rpm and when timed is was extremely close. 

Use of an encoder  or multislotted disc will probably not come about until after the new version of MACH is released.

I am sure someone else will chime in about CSS. I don't use it.

RICH

Down to 1 rpm is fine. I figured with a single pulse that wouldn't be very accurate at 1 rpm.