[Dave1024]

Hello all,
I built a DIY 3-axis mill from eBay parts years ago and it has always performed well. The other day I went to use it and all of a sudden M0 no longer shuts off the spindle. I'm stumped! I have searched high and low but I cannot find anything that allows me to set this. I have done nothing out of the ordinary; I have not screwed around with any settings before this happened. It simply stopped working.

I am running Mach3 with a Gecko drive, nothing special. My spindle turns on or off with Output #4, and I set the speed manually. Everything else works so I am sure the hardware is OK. I can turn the spindle on or off using the Spindle button on Mach. M3 turns the spindle on, and M30 turns it off just like they should. M0 has always turned off the spindle too, and it has been doing that countless times for many years until now. Does anyone know where this functionality is set in Mach3?

[HuFlungDung]

I don't know about Mach3, but some controller software only permits one M code per line.

Actually, M5 is your spindle stop command, but M0 and M 30 might be set up to do this in the PLC (or equivalent), depending on the desire of the builder. If running lathes, you probably don't want the spindle to stop all the time on an M0. Strictly speaking, M0 is a program stop, and what it does to the machine is up to the builder.

[Dave1024]

Thank you for your reply, I appreciate that. The M5 code works just fine and I have modified all of my post-processors to include it. It should have been that way all the time for completeness in hind sight.

It is still a mystery why M0 stopped shutting off the spindle all of a sudden.