After homing X and Y, can I auto move to a non 0,0 location?

If the HOME_SEARCH_VEL and HOME_LATCH_VEL are positive, the axis will move to the switch, back off it, and re-engage it at LATCH_VEL until the signal changes state (again).

If the HOME_LATCH_VEL is negative, the axis will move off the switch and stop as soon as the signal changes state.  No 2nd move back on to the switch, so potentially done slightly faster if your LATCH velocities are really slow.

I think one of the contributing reasons LCNC's homing is so confusing is simply the terminology selected by the developers years ago.  The terms made sense to them, of course, but I think more differentiation in terms would make homing configuration more intuitive.

Such as changing HOME_OFFSET to HOME_SWITCH_LOCATION or similar.

And of course, the current terms make sense to some people so changes would make things confusing to them.  There's no perfect answer when it comes to preferences.

Thank you very much. Homing works just the way I want it now.

I agree completely about naming -- it's very important. I didn't realize HOME_OFFSET was an absolute location until I got this working -- the word "offset" implies "delta" to me, not "location".  

As for the sign of HOME_SEARCH_VEL and HOME_LATCH_VEL, I've decided to try them with different signs, to eliminate the backoff step, as you suggest.  There may be (probably is) a difference between where the switch closes and where it opens, but for my mill I'm sure it won't matter, for homing purposes.

My final X config is this.  Y is identical, except HOME is 0, not 6, to keep the bed at maximum extension toward me.

pgf wrote:

Okay, I think a picture will help.

That's because since homing (and even rapids, on my mill) are very slow, I'd really rather skip the extra bed travel, and have it home directly to 12, and stayed there.
 

Homing does not have to be slow but there is a tradeoff between overtravel and velocity. Now you have it working, try playing with the HOME_VELOCITY and LATCH_VELOCITY. ON my plasma table, I settled on 12 metres/minute

Ha!!! My motors stall if I go much over 40 inches / minute!

pgf wrote:

Ha!!! My motors stall if I go much over 40 inches / minute!
 

That seems exceptionally slow.

Is there a problem with your machine - perhaps axis binding - or do you have really undersized motors?

Heh. I would have to say probably "yes", to both. LOL.

It's a DIY mill. In 1993, II got it as a kit, which included the stepper, a driver board (which did just raw coil driving -- not even step/dir!) along with plans for a chassis made of particle board, rails from high quality drawer slides, and all-thread rod as the transport. The s/w that came with it was written for DOS, polling loops and all.

There have obviously been a lot of upgrades over the years: EMC/LinuxCNC in 2004, acme rod for X and Y (Z still uses the all-thread) a lot of chassis strengthening, a real step/dir driver board maybe 10 years ago, and a Mesa card and Raspberry Pi this year. But it still has the same steppers, and the linkages and threaded shafts aren't all that well aligned. Frankly, I'm amazed it all kind of still works. But I have fun with it... when it's not driving me nuts!

Pictures here: projects.foxharp.net/cnc/