Another gantry mode limit switch question

[rforney]

Hi,

I have slaved the D axis to the X axis, in order to drive a gantry. I have a limit switch hooked up for testing, through the X axis wiring on the galil. Whenever I activate the X axis limit switch, the D-Axis limit switches light up with the X axis limit switch (on the Mach diagnostic screen). The D axis limit switch is not hooked up at all. Why is this?

My second question is regarding the home sequence for a slaved gantry. If the gantry is bolted together "square", and I press home, will it be able to find both gantry home switches (X and D), without racking my gantry?  Ideally, I would like to home to an index on both axis, so that once I do square the gantry (initial machine setup), it would stay that way.

I wish there was a little more documentation on this. Galil documentation for the homing routines are okay, but I am not sure what applies to the Mach Galil plugin. Thank you for your help!

Rob

[smurph]

I would suspect that Mach treats the gantry axes as one axis.  Thus when the limit is tripped, Mach does the same for the slaved axis.

Homing...  It's supposed to home both gantry axes at the same time because they are geared together with GR (operating on the master axis switches).  Then, if axis squaring is checked in the config, it will decouple the axes and home the slaved axis to it's switches and then recouple the axes.  This second op should not move the axis very much.  Just enough to square the gantry.  In theory, that's how it should work.  But I have no way of testing it because I don't have a gantry machine.

Steve

[ger21]

I would suspect that Mach treats the gantry axes as one axis.  Thus when the limit is tripped, Mach does the same for the slaved axis.

Steve

There are two different ways to configure the slaved axis homing. The normal way is both sides of a gantry move toward the switches together, but each side uses it's own switch, to "auto square" the gantry.

The second option, in General Config,  "Home Slave with master" uses a single switch, and syncs the motors throughout the homing process.

[rforney]

Thanks, fella's.  The limit switch problem went away once I correctly mapped the drives. I had two X axis in mach!

As for the homing routine, I can see that there are a few options. I wish there were a way to square the gantry, uncouple the servos from the gearboxes, turn the servo to the index mark, and then recouple the servos to the gearboxes.  Perhaps then I could use one limit switch, homing the first servo and moving to the index, then moving the other servo to the index.  That way, I could be certain not to rack the gantry a whole lot.

I may just place them in gantry mode, and home one side.  As always, open to any and all suggestions.

Rob