Torch not raising when finished

[cbassjr]

I have developed a problem with the torch not raising when it finishes cutting but rather stays down and drags across the top of the sheet to the starting position. This started about a couple of weeks ago luckily I have the breakaway torch holder after I installed one a the laser sights I purchased and had to adjust the torch to install it. I am getting ready to take the lasers back off but I don't think that's going to solve my problem.

[acourtjester]

in "job options" there is the rapid height but if it is only doing at the end for the job that is not it. I have mine set to 1.25"

[urbnsr]

If you could post some of the code, it may indicate (or not) where the problem may be.

Paul

[beefy]

If you could post some of the code, it may indicate (or not) where the problem may be.

Paul

Exactly my thoughts.

As soon as I get a problem where the table is doing wrong things, I want to know if the table is being given the correct instructions, i.e. is it doing exactly what the gcode is telling it to do.

That quickly determines if the table has a problem or the software is not generating the correct code. Knowing where to look for the problem is half the battle.

I actually always have a quick glance through my tap file (gcode) immediately after it's been generated. I don't go through it line by line, just look at the obvious things like feedrate, touch off, raising to safe Z after cuts, etc. It's pretty simple gcode in plasma cutting, and well worth learning how to read it.

Keith

[acourtjester]

Like Beefy and Urbusr state looking at the G-code helps. You can scroll through and stop at the M3 commands and a few lines before and after tell you where the torch is (Z height) speed (F number) mach will only changes speed when told to. There is Z pierce height before and after cut height for cutting most likely 2 speed changes there. Then do the same for the M5 command this is after the cutting as to where it is going how high the Z is off the metal for moving to the next part or home. All the line between are the movement of the torch while cutting most of the problems here is metal warping and or THC problems.

[hacnwac]

A couple months ago my torch wasn't going down to pierce properly after the first one. It ended up the z slide was a little gummed up. A little cleaning worked like a charm. Might work the opposite way too.

[urbnsr]

Exactly my thoughts.

As soon as I get a problem where the table is doing wrong things, I want to know if the table is being given the correct instructions, i.e. is it doing exactly what the gcode is telling it to do.
.....

Keith

Yep - Keith said it better - If an issue is in the gcode, the table (when working correctly) is only following instructions. And I recently went through something similar and found a problem that I created in my touch-off subroutine, not realizing the subroutine gets interpreted on the fly. That caused the torch to "skate" across the material from one cut to the next.

I posted my code on a forum and while that didn't show the problem directly, a posted reply got me to think about my subroutine. And there it was.

Paul

[vmax549]

Sounds like you are loosing steps in the Z axis. As long as the THC is controlling Z then it stays at control height BUT as soon as it stops controlling the the torch stays buried in the material and drags. WHEN the troch stops STOP and look at teh values for the Z axis it shoudl be at the control height+- . IF it is WAY off then look for lost steps. Lower the Setting for Z control % by 25% and test again.

Just a thought , (;-) TP

[cbassjr]

in "job options" there is the rapid height but if it is only doing at the end for the job that is not it. I have mine set to 1.25"

Thanks this is what it was. I talked with Scott this morning as I had to cut a big gate panel for a customer and didn't want a torch drag problem. He recommended 1.5 and everything worked fine. I've attached a pic of the gate panel.

[acourtjester]

It great when you get the bugs worked
nice job on the gate

[cbassjr]

Thanks. ...