RUN REVERSE, Serious problem

[mrpeja]

Last days I experienced serious problem. I have build plasma table one year ago and works well. But I want to convert it to oxy fuel cutter. Very often I need to activate Run reverse. And there is big problem.
First I press Hold and then Run reverse. Program starts reverse, but sometimes instantly and sometimes after couple of lines, Z axis goes UP to Rapid clearance and stays here and I don't have control anymore. I have test everything I can remember, but problem persists.
So I need help.
I'm not sure where is the problem: in Mach3 or in SheetCam or I missed something to do in my config or in sequence of pressing buttons or in place where to press Hold, or...
I use Sheetcam post processor THC300 G31 and floating head switch.
Mrpeja, licensed user

[manmeran]

this is exactly my problem

[ger21]

Do you have SafeZ turned on?

[BR549]

I think the problem IS that mach does not know how to deal with the TOM routine(top of material) and the constant resetting of the Z with G92.

In order for the TOM with a G31 OR G28.1 to work it HAS to cycle the code first to find the surface then Reset the Z with the G92. SO when the planner runs the code backwards it does not know to CYCLE the TOM routine first as it processes the code in reverse.

Here it also does not cycle the Torch start/stop properly it just leaves the torch on til the EOF.

We have learned to just repeat the section of code rather than ReverseRun.


Hope that helps

[zealous]

From my understanding "Reverse Run" will also NOT read MCodes and such.
If you press the stop button rather then resuming from a FeedHold do you get the same results?

[manmeran]

i do , Z goto up and Z-safe is off.
Very strange.

amir

[mrpeja]

To zealous: when I press Stop instead of Hold, than all is lost, much worse than Hold.
To BR549: Do you have idea how to solve problem with G31 and G28.1 for oxy fuel and plasma use?
To Ger21: I have SafeZ turned OFF.

[BR549]

Sorry but to my knowledge there is NO solution for Jet cutting using rev run. The only solution is to feedhold, stop then reset the last section to recut  and restart the cut.

The fix would have to be done at the CORE LEVEL in mach.

(;-) TP

[mrpeja]

Hi BR549,
Thx for the reply. Maybe someone in charge could do things  at the CORE LEVEL in Mach.
Community will appreciate this.
Before this happens, please explain this: fedhold, stop, reset last section and restart the cut with more details.
For now, I do something like this in SheetCam, extracting parts being cut and start new job.
Maybe you know simple way to do?

[manmeran]

I have THC, and  have "FAULT pin" .
 if torch was turn off then fault is ON. we connect fault pin to buttom "feedhold" and if in While cut torch was off, then Automatically machine pause and we repair our problem
I think the pause is more safe than the reverse run
 It is practical ?