Y with A as slave axis won't work

[Neale]

It's easier to just drop power to the drivers so the motors can turn and just turn the screw by hand. I had a home switch on A as well as X and used that to do manual homing of the slave axis using the led on the proximity switch. It's not absolutely exact as the motor will them jump to the nearest full step when you reapply power but that's not really a big issue on the kind of machine that uses a gantry (I.e. for woodwork).

You do have driver stall detect wired back to the ip/M, I hope? This means that if one motor stalls, the machine doesn't try to wind the gantry off the rails!

Written by ex-IP/M owner...