Centroid Community CNC Support Forum

4th axis won't home. Worked great yesterday. Shut down the machine last night, come in today and it just spins and never finds home. It spins really really slowly, too. Normally it rapids around, trips, and then touches slowly. It's just creeping around now. Made several full revolutions at this point. Report is attached. Any suggestions? I guess my home switch could be busted, but why would it just creep around and never make a rapid attempt first?

Thanks!

What type of switch are you using?
Does that input change state when looking at the inputs on the live IO screen (Alt + I) when you trigger it manually?

Include a report and a screen grab of your IO configuration Wizard page

Probably the home switch circuit (INP30) is already open (red on the Alt-i display).

In that case the control goes directly to the second step: moving slowly in the W- direction waiting for the switch to clear and close again.

If the switch is not accessible, just use the Alt-i display to see the state of INP30, and to see what it does as you jog the rotary table all the way around.

For correct operation, the home switch input should be Green through most of the travel, and Red for a few degrees where the switch is tripped.

I did alt-i and the 4th axis circuit red all the way around. I can't access the switch without taking the axis apart, prefer not to do that.

I tried just manually homing it to some random position and it worked. I re-zero it every time I set up anyway, so home for this axis is pretty pointless. So while the real problem isn't fixed, I can still run my parts. Guess next time is needs repaired, I'll have a look at the switch, until then, I think I'm good to go.

You might check wiring connections for that switch to see if you find something loose.
If you don't want the rotary axis to seek home, and are content with the control setting home right where it is on start up, you can modify the cnc10m.hom file by placing a semi colon in front of M92/W until you get the homing circuit fixed.

M92/Z
M26/Z
M91/X
M26/X
M92/Y
M26/Y
M11
;M92/W
M26/W

Machine repair guy came in the other day. The switch was out of adjustment. The 4th axis uses a mechanical switch to find home and it needed tweaked. All good now!

thanks for reporting back