Quote Originally Posted by JAZZCNC View Post
This one is easy enough. In homing and limits use the home Off option and it will backoff the switch what ever amount you enter. Then Zero the machine coords.
Thanks for the comments, Jazz. Unfortunately, I don't think that this is the answer. You told me about this one a few years ago when i first built the machine. I have it set to home Z, then X and Y together. I had the problem that the Z home/limit switch was a bit sensitive and once the gantry started moving after homing Z, it tripped. I fixed that as suggested. I've just been out to the machine and done a few experiments. Even with a homing offset of 10mm on all three axes, I get "limit switch triggered" if I use the MDI to move away from the home position. Same thing if I jog any two axes away from home with the MPG first. If I jog all three axes away, it works fine. Makes no sense to me!


Quote Originally Posted by JAZZCNC View Post
This one I'm not so sure about. I've had similar things happen from time to time but cannot figure out why. Usually, thou when it happens just re-homing and everything's good.
Been experimenting with this one as well. I homed the machine, did a "regen toolpath", and hit Start. Soft-limit warning. Rehome, regen toolpath, jog machine with MPG off home position in all three axes - works OK. I suspect that what might happen is I often start a job after jogging to roughly the right area with the MPG in X,Y, but leave it at Z home position. In future, I shall try to move off Z home before starting the run and see what happens.

I'm running 3.043 as the later versions don't work properly with the IP/M. Not sure if there are other places where it fails but I know that later Mach3 versions can't handle tool height setting between M6Start and M6End, which makes it a bit difficult to use if you need to change tools. Maybe the MPG plugin complicates things as well, but it's too useful to give up! My money is on an internal software problem that only shows with this combination of hardware.

If the IP/M blew up, I would swap for UC300ETH/UB-1 which looks like a fairly straightforward change (24V signalling, etc) but the IP/M is so bullet-proof that it will probably still be running when the rest has crumbled to dust...