Auto-squaring possible with separate home switches on each axis?

[clough42]

Is it possible to use auto-homing and auto-squaring on a gantry machine with dual drive Y axes and separate home switch inputs for each axis?

I'm running with software pairing, with separate home switches on each of the X, Y, Z, and A (slave) axes, with the inputs defined as FirstAxisHomeOK, SecondAxisHomeOK, ThirdAxisHomeOK, and SlavedHomeInput. But it looks like the auto-homing and auto-squaring script is expecting me to have HomeAll defined, and starts backing off "to clear the switch" when it gets to the Y axis. I expected it to use SecondAxisHomeOK and SlavedHomeInput for the homing/squaring, but it looks like maybe this isn't supported?

Is there a way to make this work, or do I need to just give up, wire my home switches together, and use HomeAll and SlavedHomeInput?

[ShawnM]

I retrofit a 6x12 router with auto squaring and paring wired per the manual that states that one of the requirements is to wire the first 3 N/C proximity switches in series to the HomeAll input. I have not tried any other way as I was instructed to follow the manual word by word. It may be possible to write your own custom homing macro but why? Also, since the wizard is set up to also display which input you set for HomeAll on the axis paring page it’s doubtful you can do it another way.

[Gary Campbell]

Is it possible to use auto-homing and auto-squaring on a gantry machine with dual drive Y axes and separate home switch inputs for each axis?

I'm running with software pairing, with separate home switches on each of the X, Y, Z, and A (slave) axes, with the inputs defined as FirstAxisHomeOK, SecondAxisHomeOK, ThirdAxisHomeOK, and SlavedHomeInput. But it looks like the auto-homing and auto-squaring script is expecting me to have HomeAll defined, and starts backing off "to clear the switch" when it gets to the Y axis. I expected it to use SecondAxisHomeOK and SlavedHomeInput for the homing/squaring, but it looks like maybe this isn't supported?

Is there a way to make this work, or do I need to just give up, wire my home switches together, and use HomeAll and SlavedHomeInput?

Yes it is, with the following caveat:
You will have to write your own macro for the autosquaring. Eric S. and a number of others have done this, some have shared their versions here on the forum. So if you are comfortable reading over the OEM supported autosquare macro and making a few input reassignments or don't mind spending the time to learn a bit of macro coding you should be able to pull it off. If not, go with the supported version until you have the required skills to make your own.

[clough42]

Thanks for the responses. This is what I suspected, but thought I'd ask.

I write software for a living, so I can certainly code a macro, but I also see the value in walking the well-worn path when there's no benefit to doing otherwise. When I was planning the build, I had enough inputs, so I went ahead and used them, but having a little more experience with Acorn and CNC12, it's clear I'm only making things harder.

[Gary Campbell]

As Shawn states, in order to use the Centroid provided macros, and receive support, HomeAll must be used, and you will also be required to "hit" the slave sensor first.

Personally I am not a fan of either, so if I had a machine that requires gantry squaring I would take an hour and mod the OEM macro.

Good luck with your build

[ShawnM]

Thanks for the responses. This is what I suspected, but thought I'd ask.

I write software for a living, so I can certainly code a macro, but I also see the value in walking the well-worn path when there's no benefit to doing otherwise. When I was planning the build, I had enough inputs, so I went ahead and used them, but having a little more experience with Acorn and CNC12, it's clear I'm only making things harder.

Yes, clearly making things a little harder when there is no need to. The OEM setup works and works great, just the way Centroid programmed it. Saving inputs is a good thing as you will no doubt want to add more features down the road and may need an input or two.

[tblough]

One thing to be forewarned about. The Centroid autosquaring routine clears the soft limits at the start of the routine and then restores them at the end.

If something happens that prevents the autosquare routine from finishing, your soft limits will remain cleared and you will need to manually re-set them.

[ShawnM]

Yup, there are two pitfalls to the auto squaring routine, see page 20 of the manual for all the details.

[clough42]

One thing to be forewarned about. The Centroid autosquaring routine clears the soft limits at the start of the routine and then restores them at the end.

If something happens that prevents the autosquare routine from finishing, your soft limits will remain cleared and you will need to manually re-set them.

I actually saw this. Something weird happened once, and after unpairing, it slowly backed the master axis away from the stop instead of towards it. I hit ESTOP after about an inch, and noticed later that the limits were gone.

I've run it many times since, and haven't seen that behavior again. No idea what that was about.

[suntravel]

You could connect both ballscrews with a timing belt to prevent the machine get twisted if one servo fails:

http://www.m-hoch-5.de/uploads/images/PFM2_04.JPG

Uwe