Hi guys, me again,
I wonder if anyone has experienced this. On one machine we have added an external MPG wheel to the front console, it works very well using Chaoticone’s script for his CNC4PC Pendant. Slightly modified, but all good. A five position rotary selector switch for OFF, and the four axes X, Y, Z, and A.
When running G Code, the MPG and Jogging are not available of course, but when Feed Hold is pressed, if the MPG is not in the OFF position, which can happen, and it is accidentally bumped, then it mimics the Cycle Start command and the G Code starts running again. I must say, that makes you sit up and take notice!
Well, just make sure the switch for the MPG is in the OFF position…. Yes of course, but if things can go wrong, then they might. It gets better. When Feed Hold is press again or Cycle Stop is pressed in an attempt to halt the unwanted action, the screen freezes and the machine just keeps on running. I assume Mach or the PC is still running the G Code in the background. It then requires E-Stop to halt the action. Not very convenient.
That part may just be on our set up for whatever reason, but I assume the MPG acting as a proxy Cycle Start is normal. My thought is to set things up like on my current mill and I have seen elsewhere, where the selector switch unless in the OFF position actually prevents the Cycle Start from acting. Not sure if that is what is happening internally, but that is the effect.
Is this a good solution?
Have a normally closed contact from the OFF position in the selector switch activate an input, say input 63, then modify the Cycle Start function to include that input in the things it looks for before it can be actioned?
I have the input happening and have attempted to add that input to the “if/then” statement in the Cycle Start script, but I really have no idea what I am doing. I don’t want to just keep trying stuff as this is more than just a desire, it’s now quite a potential safety issue if I don’t get it right, or get it half right.
Any suggestions welcome and anyone with an external MPG wired in, be aware. If using a pendant with a Dead Man switch, then that takes care of it, but we don’t want a Dead Man switch, as I believe one of your hands is rendered unusable while holding in the switch.
Craig.