Homing cloned axis#6 at PMDX-126

[Uncle_Euge]

Hi everyone. What a pleasure to join the cnc comunity at this forum. I just have built my first cnc router around pmdx-126 logic board. Everithing runs well, appart one cornerstone (literally) issue. I am having quite a pain trying to square off the gantry.

I have wired the Y slave(axis#6) to J5 pins D and C, which are cloned/inverted and cloned from J4 pins 2 and 3 respectively. As I understrand the matter, the Y slave always going to repeat steps and directions of Y motor. That makes Y slave irresponsive to any limit switches assigned to it in the Input Signal menu of Mach3. The only way out as I see is to rewire the Y slave to any other left spare Axis port. That, however, robs me one axis, leaving with 5 active inputs, rather than 6.

Please correct me if I am wrong in my assumptions. Any advise will be much appreciated.
 

[12strings]

The PMDX-126 "Jumbo Mode" is not capable of squaring the two motors on the cloned axis.  That is a trade off of the hardware cloned step and direction signals.  And since Mach sees the motor and its cloned signals as a single motor, it can only have 1 home, 1 positive limit and 1 negative limit switch input for that pair of motors.

You have at least two options: (1) Don't use the PMDX-126's axis #6 (the one cloned from axis #1), which does indeed leave you with 5 motors, or (2) design your machine so that you can square the gantry by running it against the stops until both motors start cogging, then back off the stops and home using the single home switch to establish the home position.

[Uncle_Euge]

Hey 12strings
thank you for reply. That exactly what I thought, and at the moment I had to leave axis#6 behind, using other inputs instead. Shall look for second option of your when the need arises in future. Thanks again, mate.