Mach3 - weird coodinate shift with inch/mm gcode change

[Neale]

My feeling is that software (and anything else that is supposed to help us) should allow us to do the job the way we want, and not impose unnecessary restrictions on us that could be avoided. Yes, we can't beat the laws of physics and some other physical constraints. There is also the valid point, as I alluded to earlier, that the software designer may have a different "world view" from a user which implies a certain way of working. I'm happy, more or less, with that as long as the implementation is consistent - which it does not appear to be in this case.

Nevertheless, Mach3 is well beyond its "best before" date so no-one is going to fix it, and fortunately there are a couple of easy workarounds in this case which mean that I do not have to manage two machine profiles or unreasonably change my way of working. Ho hum - that's life.

Gerry - out of interest, do you know what UCCNC would do in this situation? Does it recognise G20/21 and just do what you might expect?

[Ger21]

UCCNC is unitless, so it will not do anything if it sees a G20 or G21. If you want to run both metric and imperial code, you need to setup separate profiles and use the appropriate one.

[magicniner]

+1
Machine profiles, one for each set of units is definitely the way forward if for some unfathomable reason switching between systems of measurements.