I recently purchased the LMS SX2 (aka HiTorque 3900), and a cnc fusion kit. The conversion is nearly complete, with only a small amount of wiring remaining to be done.

I've got 4 relays available, and plenty of IO to do just about anything (My controller is a Mesa 7i43 with 7i47S and 7i42 daughterboards, great stuff). I'm using steppers instead of servos,

I've already added the ability to control forward/reverse, but how did everyone approach controlling the spindle?

The 7i47S has a VFD/Analog controller that can replace a potentiometer - which is simple enough. Is there a preferred way to maintain manual control as well?

Controlling the spindle on/off is something I'd prefer to do by keeping the built-in switch in the E-Stop loop. Does everyone simply turn it "on" manually and then use the relay to control the mains power? Looking at the built-in switch I was hoping I could wire a relay in series with the power switch, or maybe replace the built-in power switch with an e-stop. Ideas?