forum.cncdrive.com

Hi,
I have upgraded my workbee CNC from a Mach3/BOB to Mach3 / AXXB-E. I have nearly everything working, including dual homing for my Y & A axis and the soft limits are fine.
Although the soft limits are OK, I really wanted the home switches to also become the (--) limits for all axis when in normal operation I have a few limit switch questions but think if I can crack the first question everything else may fall into place.

Question
1. How the heck do I get this controller to backoff the home switches once the axis is homed. ?
2. In Mach3, The plugin also states there is a new version available ( currently version 1) however if I press update nothing really happens.

Thank you

Rob
Australia

If you are using Mach3, the machine will back off the switches until they open, but no farther. You can create a custom homing macro to get them to back off the switch, but that's really the only way. If you switch to UCCNC, it has a backoff setting.

2) Check the plugins folder, and see if a new version was downloaded and saved there.

Thanks for the reply….I agree with you it should back off and open the home switch but using the axxb / mach3 combo mine does not do that…

I found some examples and will look at modifying the ref all macro in mach3 to move off the home switches once homed.

Then you probably have noise or switch bounce triggering the switch too early.

Not sure if people have seen a lot of switch bounce when using proximity switches. Plus when i did have the home switches as limit switches noise would cause spurious estops if the limit switches had noise. I might try and replace one npn prox (which is configured active low) with a pnp version just to see if theres something strange (bug) with the software.

I think uccnc has a demo license, I could also test out the shared home/limit configuration, but I domlike the
Mach3 dark screen set

Maybe your home switches are setup inverted (active low checkbox of the home input pin).
Verify that with moving the axes off the home switch and in Mach3 check if the Home LEDs or on or off, they should be off this way, if they are on this way then invert the active low setting for that axis.
If the home switch polarity is setup incorrectly then the controller will start with the moving off sequence because it will think that the axis is already on the switch which it is not, so then it will finish with pressing the switch and then stop on the switch.
So, maybe this is the problem.

Thank you -" Maybe your home switches are setup inverted (active low checkbox of the home input pin)."

I set the home limits active low because they were NPN proxmity switches (which was obviously incorrect) . Although everything seemed to work you are correct in that changing the setup to remove "Active low" has corrected the issue and now the controller backs off the HOME limits. These HOME limit switches are now working correctly as my "--" "++" limits in normal operations. woohoo

I really appreciate your input and the AXBB-E has allowed me to easily incorporate relays for emerg stop to cut power to the steppers and solenoids for the air supply. I have the UCCNC software still on my wish list and hope to incorporate it soon.