Plasma floating head...

[Davek0974]

So it will work, but not a good method.

is there a way to have g92.1 run at then of every cycle?

maybe not important as every job will use the probe/offset method surely it will get set/reset many times during a job and a retained offset would only matter if I were then to run a manual part after an auto probed run??

i gather doing a home-all would clear any offsets or not?

[JAZZCNC]

So it will work, but not a good method.

is there a way to have g92.1 run at then of every cycle?

maybe not important as every job will use the probe/offset method surely it will get set/reset many times during a job and a retained offset would only matter if I were then to run a manual part after an auto probed run??

i gather doing a home-all would clear any offsets or not?

Yes will work and yes there are better ways.

No offsets are not cancelled with Ref all home this is one of the dangers with them.
What you need to understand is there are 2 coordinate systems, WORK and MACHINE. When you Ref home you are defining the MACHINE Zero coordinate position which is fixed and never changes unless you move the Switches.
Work coordinate Zero can be anywhere on the Machine. G92 Coordinate Offsets are offsets from currant WORK coordinate point and stay in affect until cancelled. So even if you load another G-code file the previous offsets still apply if a G92.1 hisn't given before closing the file.

When you use G92 nothing moves it just defines a new Point which you then work from. Plus the other thing which can cause problems is that G92 only works with Absolute moves so any incremental moves will use the WORK coordinate offset.

A much better way is to Define a user Macro which has the G31 move to find material height which then Zero's the WORK coordinate DRO's, then move to any heights you'd like. With this setup you don't run the risk of falling foul with offsets and can have much more flexabilty and control of what happens.
You can even setup User DRO's on the screen set to enter preset and pierce height etc.
All you do then is alter the Sheet cam post so it enters the Macro name in the G-code at the appropriate point or points needed. Mach3 does the rest.