Hi everyone , i have custom cnc plasma table that i build . I use mach3 and sheetcam software . I have proma thc and i need to make a new rules on sheetcam to turn off and turn on thc when cutting holes. I d'ont know if its possible to create a maccro on mach3 that i will use on sheetcam rules ?

No, i don't think you can do this, the feature you want is available on integrated THC systems but not something you can do on the proma as it controls the height on its own.

Also there is a problem in running a macro in Mach3 while the system is in motion  - it causes a stutter in motion while the macro is processed.

Now, having said that, I might try this - do all the cuts you need no THC for first, make as a separate tool path and simply turn the proma off. Then do the cuts with THC and turn it on maybe??

For integration like this I think the minimum you need is something like THC from CandCNC but you are looking at £800 or more i think, this will give full THC control from within SheetCam but it comes at a cost

Ok thanks

Maybe, its not something i have tried, speed will be the issue - it might not switch off quick enough to make a difference.

I would not use the relay to switch the proma off, use it to disconnect the down signal so the torch does not dive

Yeah good idea !   How can i know the code from g code of an output ?  For example output 1 ??

Do a google search for Mach3 macro programming, and similar, there are a few documents that will help you a lot, there is no actual g-code for an output, its all done via macro's

you will need a couple of custom macro's say M1450 and M1451 maybe - M1450 would contain ActivateSignal(Output1) and M1451 would contain DeactivateSignal(Output1)

when you want to turn your output on the code will call M1450 etc, the macros live your macros folder and do not use any numbers that exist already in there.

the trick is getting the code into your post processor.

but dont forget - there will be a glitch in your X/Y motion when the macro is called, will it matter? Thats up to you


edit
Get the list of macro commands - if i recall there is a built-in call that can turn THC on an off, maybe that will be better.

Hello,
I am having a similar problem
Mach3+sheetcam+WinXP+Proma150
Mach3 is constantly resetting the Z height from THC corrections. so the program cycle pierces lower and lower until it crashes into material. I do not use a touch off, only torch up/torch down, i need the other pins for other things. The odd thing is I have been plasma cutting with the same setup for years without this issue. Several separate setups. Just this setup its now an issue. All I want to do is disable the THC corrections from resetting the Z height, so it pierces same programmed z every time regardless of THC corrections. I cant work out if mach 3 is obeying on pierce or during cut or end of cut. The non THC post in sheetcam has always worked using Proma as I knew this post doesn't reference height during cutting.