Can someone tell me which pin to use or how to configure Mach to use the 110 AC Solid State Relay?  It says pin one on it.  When i configure mach to use pin 1 is turns on and off the pin 1 which is located with the step / direction pins.  I will like to use an high speed Dremel tool and control it on/off with the program. 

Hi Dajavu,

The charge pump safety circuit for spindle control should be what you are looking for, here is the link:-

http://www.machsupport.com/docs/ChargePumpSafety.pdf


Tweakie.