[D.D.Machine]

hears the deal I need to hook up a DIY 4th axis running off a PC to index "ONLY" and I need some way to tell the PC when to index and on my fadal VMC I have a spare 110V coolent relay that triggers off a M code .... so my idea is why not use the 110V relay to talk to a 5V switch to tell the PC to index... It looks like it well work to me

and one tryed it ?

Thanks Duffy

[Geof]

Your idea is to have the 110V AC output operate a relay with a 110volt coil and use the contacts on the relay to switch your 5 volts. The PC looks for the presence of 5 volts at some input and indexes the 4th axis. The only problem you might find is that the relay contacts might bounce as they close; this means the PC sees 5 volts then the bounce turns it off and then on again so you might get two indexes depending on how your PC reacts to two closely spaced signals.

[miljnor]

use a capacitor to keep the signal from bouncing with the contactor(on the 5volts side ). It will slow the signal down but were talking milliseconds here. So it should work