I’m about to re-assemble my Altmill 4x4 after replacing the H100 VFD and that got me thinking about safety interlocks to prevent the spindle from starting unintentionally.
This particular VFD won’t run unless you tie its X1 pin to ground. Many people online suggest adding a jumper wire between X1 and ground so that the VFD is always enabled. Others suggest that you should use an opto-coupler/relay to allow the CNC’s controller to enable/disable the relay. I’m wondering what the current recommendation is for safety interlock on the Altmill.
Reading the SLB-EXT documentation, it seems like you can set up its auxiliary switches to be controlled by M commands. M3/M4 = switch closed, M5= switch open. It seems like this could be used to allow the controller to handle enabling/disabling the VFD based on whether it’s commanded the spindle to move, negating the need for an extra optocoupler/relay. Is this the case? Is anyone running this setup?
Thanks,
Kieran