QTPlasmaC post processor - SheetCam?

Still using the fine cut consumables but much faster cut rates. The slag pops right off now. You can see where I’m getting alittle wiggle around sharp direction changes so I’m not sure going up to 250”/min will be beneficial with the standard consumables.

Copy that just was curious!

Glad to hear you’re getting better results

I just watched your YouTube video on you high speed ohmic and it’s impressive. I’m sitting at 20”/sec starting at 1”. I tryied 50”/sec and I seamed to tap the sheet hard enough to float the torch up a smidge which is unacceptable as I normally use small 11x23” sheets of thin material and that hard of a tap can shift them. Abd these sheets are quite pricy at $200-$300 each. I would like to speed it up but if I can’t then I understand. Here is a video of the test cutting. Any recommendations? 

oh and one other question. I only have one switch on each axis for the home/limit switch. In the past I just used them as limit switches but on this install I used them as combination home/limit switches. So now I can auto home the system but once it homes the first axis it stops moving because it thinks it reached the hard stop switch. Is there a way to program in a retract off axis after homing so it does not trigger this hard stop alarm?

in the ini file
HOME_OFFSET = -3
if metric
and
HOME_IGNORE_LIMITS = YES
So it does not trip limits while homing.
Left some comments on the video.

JTknives wrote:

I just watched your YouTube video on you high speed ohmic and it’s impressive. 

I assume you mean this one

I had a job which I filled a 8' x 4' sheet with some flanges and small parts. I cut it in 3 sections on a 4' x 4' table and there were heaps of probing so over time I tweaked the probing routine heights etc. I was using my hypersensing which uses a THCAD for the ohmic sensing. it does not like Hypertherm machines on a water table but it would work for you by the look.

Part of the speed comes from the way it breaks contact on up travel because as soon as it senses a fall in voltage, probing finishes (before the contact is broken).
I've been sent a ohmic circuit from Proma Elextronika in Poland. Its a very nice piece of kit and have some very good reviews on it. This will by my water table solution.

Oh ok so you’re not waiting for the voltage to go to zero to trigger the contact. Your looking at any voltage drop and once it does it’s triggering contact. That make perfect sense to use a thcad and watch the frequency output. Then you could set the trip frequency on the encoder input on your mesa board. I wonder if there is a way to double duty a single thcad-10.

You know I stumbled upon something the other day by accident that could work. I was using my fine cut consumables. And I was testing my retraction to make sure my actual retraction was what the display was stating it was. I held the ohmic button down and moved z down till it stopped from the ohmic trip. But I noticed when it touched I seen a +10v on the cut voltage. I did it agian and it was still there. So I started looking around and found a tiny slag bead stuck up in the nozzle bridging the nozzle to the shield. This was back feeding the ohmic voltage into the nozzle and it was showing up on the cut voltage.

Would there be a way to use this to sense ohmic. I don't know the ramifications to running the nozzle bridged to shield but it had been like that for awhile as I had just been cutting.