For PhillC regarding PlasmaC and Z axis stuff

This is for discussing some issues with the way PlasmaC uses the Z axis setup.
First, thank you for some magnificent work on it, and all the others that helped. and some that pushed you in the wrong direction !
Second, i am really sorry for refraining myself from the development of it as it had nothing to do with you, well it had everything to do with you, you put every idea presented into it ! For that i do admire your will, but one such proposal is causing grief for other users now, and i am pretty sure who proposed it and i am also sure i mentioned it was wrong, but no pointing fingers, that does not fix anything.
Also sorry for not testing this earlier, but now i am going to have all new and some old machines using PlasmaC, i have to make sure everything works with the hardware in use.
The main issue with the Z axis is that it uses positive values to work, causing a lot of issues for new users who use stepconf or pncconf to set up their machine and are glad they got it working, then setting up PlasmaC and getting tripping errors and limit reached before probe.... The wizards set the z axis to -100 to 0mm or -4 inch, so to make that work they have to edit the ini file causing even more issues.
I did make it work even with negative values, but if the min_limit for Z axis is -60 then the probe height must be set at 55 and safe height to 59 for it to work, anything else and it errors. Also why is there a complete lack of movement when those errors happen? Machine stays enabled but it will not jog by keys or button presses.
Sorry for the long winded stuff, but if it is not to much trouble, that should be fixed.
If i should post this on the original PlasmaC topic, please let me know.
Regards,
Tom
And thank you very much for everything.

That is interesting Tom, I just did some tests with negative numbers for the thread by pkasy and it seemed to work for me, the results are here .

Maybe I am not getting something. Could you post an ini file that plays up and I will have a look.

I do recall ages ago something about this but I thought it was sorted.

rodw wrote:

If I wanted a 30mm probe height what is wrong with using:
bottom + 30mm which would be -86mm + 30mm = -56mm.

I could have done that but I thought 30 (above the bottom) would be easier. Or did I misinterpret?

I did make it work even with negative values, but if the min_limit for Z axis is -60 then the probe height must be set at 55 and safe height to 59 for it to work, anything else and it errors.

Probe Height and Safe Height have nothing to do with Z axis settings.
Probe Height is the relative height above Z minimum.
Safe Height is the relative height above the material.
But of course they couldn't be greater than the Z axis range.

Also why is there a complete lack of movement when those errors happen? Machine stays enabled but it will not jog by keys or button presses.

Because I wasn't aware of them, or if I was I totally forgot.

That is how it works now.

Do you see any wierd behaviour with negative Z values.

I thought we sorted this when John was doing all the initial testing.

Yeah, I can't see any thing wrong at the moment.

I think it is a good idea to set your G54 position at the Z minimum, that way your DRO always shows the relative height above the Z minimum.