Temporarily disable limits?

[Toaster]

Hi all, I've got a couple of Centroid installs that I have done that have required me to disable limits in certain situations.

One situation is during homing. I've run into situations where a machine was moved when powered off and I can do a homing routine because there are machine limits in place. I've dealt with this in the homing routine by essentially recording the XYZ limits for the machine in temporary values, setting them to huge numbers, running the routine and then resetting them at the end of the homing routine.

This works well if the routine runs through completely. If you stop homing for any reason, the machine jog limits are gone, and the next time you run the homing routine those ridiculous numbers are recorded. The user might not realize this until they try and jog really fast home and hit an end stop.

The other trick I've done is Z limits. I am not running a job I have the Z limit set such that the but cannot be jogged into the table. Effectively the negative Z limit is the tool length.

When I start a job, in M3 I have it set to add about .06 to the Z limit, letting me cut into the table a little, but if I make a huge mistake on my G Code it won't let me bury a bit into the table. M30 sets this back when the job is over back to not letting me go into the table at all.

The same issue exists here too, if I dump out of a running job m30 never runs and my Z jog limit isn't set to what I want.

Is there a way I can automate this more? Could I have some kind of routine where when a job is not active limits get set the way I've described above? Perhaps this could be tied to the stop button in some way?

[cnckeith]

please post your home program and or any custom macros so we can see what m codes are being used what the commands they contain. and a fresh report.zip

M91/2 "seek home switch" ignores any travel limits so the machine can home out from where ever it is at to reset the machine coordinate system in the situation you describe above.

in v4.99 beta we've added "force re-home" after Estop as a user selectable feature for Acorn/AcornSix.
This combined with a custom home program and/or other custom macros (and or use work envelope feature) can do what you want.

we also recently added a way to ignore travel limits for situations like when you can't/don't want to use M91 or M92

[Toaster]

Ahh, that makes a lot of sense. I've been using the same variation of a homing routine for a few years now. For years I've been running my homing routine that way.

As you instructed I removed the limits and sure enough it works... almost.

My homing routine seeks the switches as you'd imagine. But on my machine I have it set to hit the Y switch, pull off of that switch 1.5 inches and then to an M26/Y there.

Turns out that doesn't work when your homing routine takes you into what the machine thinks is outside of the Y travel. I fixed this by seeking to the switch, doing an M26/Y and then jumping off of the switch and doing another M26/Y there. The reason I have this setup this way is that I have a fixed tool setter that sticks up. If I set my Y zero 1.5 off of the switch there's no way I can jog into it. When I do a tool change it temporarily disables the Y limit, does the tool change and hits the tool touch off, and then turns the limits back on.

I am going to check out the work envelop thing. Maybe that's something that can solve this problem in a more elegant way.