Tandum Axis Shared Home/Limit Switches

I have a XYYZ gantry router setup. The X and Z axis are built and running, Homing etc. Next for me is setting up the tandem Y axis, dual motor, dual step drivers, home limit switches.

I'm using simple micro switches for the shared Home/limits.

Generally speaking what advice would you offer for mounting and setting up the switches on a tandem axis?

1 per side can do all the homing and limits if they are mounted on the gantry, otherwise one per side is usable for one side of the limit and home, not for both limits and home.
More info would help, like parallel or Mesa ?
For Mesa Pncconf will do almost all the stuff at once.

I'm running the MESA 7i96 and plan on 4 total limits for the tandem Y axis.

I guess what I'm wondering is how to physically setup the Home/Limits so when homing the gantry doesn't rack to much. Can you physically sync the two pair of home switches? Is it necessary?

Project_Hopeless wrote: I'm running the MESA 7i96 and plan on 4 total limits for the tandem Y axis.

I guess what I'm wondering is how to physically setup the Home/Limits so when homing the gantry doesn't rack to much. Can you physically sync the two pair of home switches? Is it necessary?

When homing two tandem motors they home in sync with each other at the same time, this is achieved by making sure the the sequence No. in the ini file has a -ve sign before the sequence No.

i was thinking he means the _physical_ limit switches.
I bet he is wondering how important that the two switches be aligned to each other to stop racking.

IIRC linuxcnc moves both axis until one switch is tripped then that axis stops and the other continues till that ones stops, then they move together.

I don't see any description in the docs that thoroughly describe tandem homing.
Can anyone confirm what actually happens - for instance are back off a retrip moves done together or separately?

Chris

cmorley wrote: IIRC linuxcnc moves both axis until one switch is tripped then that axis stops and the other continues till that ones stops, then they move together.

That is correct when set properly.