Need some help setting up homing

[adt2]

I'm having some trouble getting homing working correctly on my new (first) machine. I've got Z working, homing to the top of the column. Also have Y working, homing to the -- end of the gantry.

X and A, however, are giving me fits. I've got the homing in the proper direction (toward the -- end of the X-axis rails), but they don't stop and reverse direction when they hit the limit switches.

My understanding is that they are supposed to independently home each side, in order to square the gantry each time the unit homes. The gantry is currently out of square about 3/8" over its 42" length, mainly due to operator error (I inadvertently switched off the "reverse direction" toggle on the A-axis before a jog and then made a really awful noise when I tried to jog).

So I tried to home the X-axis, thinking the homing routine would fix the out-of-square condition; but, as I said, that's not what happened. The A-axis side homed first, and it did reverse and stop, but the X-axis side never homed. It just made the awful racket that results when the pinion spins against the rack but doesn't move.

So, I loosened the X-axis pinion and manually squared it back up, then re-tightened everything. Before I try to home it again, just wondering if anybody has any pointers for this. I think I've done everything right, but that's usually the feeling I get just before I break something or end up in jail...

[ger21]

Can you post your .xml file here? You'll need to zip it.

I'm assuming you have two home switches, one for X and one for A, which are required.

Also, can you post the Homing script you're using?

[adt2]

I'll have to post the *.xml file another day...already shut down the workshop for the weekend and I'm too gassed to go back out there.

I can, however, tell you that I have no idea what homing script I'm using; certainly nothing I came up with on my own. I was under the impression that if an A-axis was defined as a slave to the X-axis then the homing routine built into Mach would handle homing both of them. Is that not correct? Do I need to write my own script to handle what seems to be a pretty basic function of this type of software?

[ger21]

I was under the impression that if an A-axis was defined as a slave to the X-axis then the homing routine built into Mach would handle homing both of them. Is that not correct?

It should work fine as-is. Although I have heard mention of some who needed to use a slightly different script. Very simple change if needed.

The A-axis side homed first, and it did reverse and stop, but the X-axis side never homed

Can you clarify this for me? They should be moving together, at the same time.

Sounds like you may have "Home Slave with Master" checked in General Config. Makes sure it's NOT Checked.
It also could be a setup issue in ports and pins, or possible the X switch isn't working? make sure you see the signal on the diagnostic page when you actuvate the switch by hand.

[adt2]

Sorry - they do move together, at the same time. But when the first side hits the home switch and reverses, the other side doesn't stop...

I'll check the "Home Slave with Master" option...now that you mention it, I do recall seeing that written somewhere else, but I don't think I've messed with it.