Hole 1? Beautiful. Hole 2? Crap. SAME HOLE!

[motoguy]

Looking for some insight on this one. I'm cutting these panels from 14ga HR. Small holes are cut first, in order marked in photo. Book specs, .2 pierce delay, .15 pierce height, .06 cut height, 270 IPM. Running hole rule that reduces feed to 55% on holes smaller than 1.5", DTHC off before hole, on after hole. .08 arc lead in, no lead out.

Both holes are on the same layer. First hole comes down, touches off, pierces, cuts great. Second hole (duplicate hole, same rules, etc) is total crap. Watching the cut, it looks like the torch is "hanging" on the hole in some way, and not having correct motion.

Photos below. The other cuts (circular hole between them, "flat" hole below, and perimeter) happen afterward, and look great.

This seems like it's a pierce height issue, with the torch being too low to the material, and getting "stuck" to it. Not sure if that's correct. I'm considering putting the 2nd hole on a different layer, to run a touch off again before cutting and see if that helps.

Any ideas on this?

ETA: cut 4 of these, and it did the same thing (some form of deformation/lack of cut) on that 2nd hole, every time.

[BTA Plasma]

Looks like you have a pierce lag like your running a 50 foot lead and need more time. Are you running a 50 foot lead?

[motoguy]

I am indeed running a 50' lead...off to the search function I go...in the meantime, anyone know what I need to do to my pierce times to compensate?

Oh, and why is the 1st hole fine, but the 2nd one horribly crappy? Seems like a pierce time issue would create two equally crappy holes. Again, DTHC is off for these small holes per my "holes" rule.

[motoguy]

I see that I have a bow in my material. Is there a way to force a touch off for each hole, or do I need to cut each hole as a separate operation (which seems to be a PITA)?

[muzza]

If your sheet is bowed it it more than likely piercing too close on subsequent pierces hence the debris left from the pierce and dragging on the sheet.

In Sheetcam you can change how often it references Z height, default is set at 250 mm on mine.

To change it go to "Options"
"Machine Options"
"Post Processor"
"Edit Post" and then you can change the distance and save.
Murray

[motoguy]

AWESOME. Thank you! I will do that. I just created ~20 different operations as a workaround, and ran it. Ran fine that way.

I like your input MUCH better!

[WyoGreen]

I have sheetcam setup to touch-off on every new pierce, and it works great. It does of course slow down the total cut time, but I'm not into production cutting anyway, so no big deal.

Good luck, Steve

[motoguy]

I have sheetcam setup to touch-off on every new pierce, and it works great. It does of course slow down the total cut time, but I'm not into production cutting anyway, so no big deal.

Good luck, Steve

I'm going to do this as well. Do you just change the Ref Distance to "0", or some small number? I changed mine to 1 "unit" (which is inches, in my case). I'd much rather touch off every time than occasionally blow a hole.

[BTA Plasma]

Yes that is actually done in Sheetcam/Options/Machine/Post processor/Set custom options. You can set ref distance to zero. It is in inches on your machine.