Hi, Jim

On My Compact 5 Lathe the index disk is about 4.5" in Dia. with about a 5/8 " slot to allow Mach to have time to see the opto Puls.

You may be able to use your Index pulse output as it is and add a IC555 Timer to reset with a adjustable time delay, R1 Var. resistor.

Just A Thought Hear, Chip

Edit: the resistor value is 1K and cap is 0.1 uf. This seemed to be the best values.

pules widening