Center Spot Sheetcam Post

As another data point, I have a one month old Hypertherm Powermax 45xp that shows the same behavior with spotting. When the torch moves to the first position, it moves to pierce height and fires the torch (110ms creates a nice dimple for me in 18g material). When the machine moves to the next location, it goes to pierce height but does not fire. The air is flowing from the first pierce. but when it tries to fire the second time, it turns off the air. Moving to the third pierce, everything works again.

Putting a G4 P20 between the first and second location does make it all work correctly. I tried a G4 P10 but it did not work. It seemed I had to wait long enough for the air to turn off (20 seconds). I suspect this is some "feature" of the machine itself but have not had a chance to call and ask Hypertherm.

I had considered just setting up my post processor to make a second tiny move and attempt to fire the torch a second time before moving to the actual second location. I think that would work but certainly is not very elegant.

Of note, the GUI showed 70V when the torch fired. For 18g material, the cut chart recommends 78V.

I use my own design board with a TLP222AF (solid state relay chip) to turn on/off the torch. The data sheet indicates a max turn on time of 2mS and max turn off time of 0.5mS.

Please let me know when you get the new version ready - I would be happy to test.

Steven

Phill, did you allow for machines that have an ArcOK signal?
It seems to me that is the problem Stefan and the Doctor had because we were trying to turn the arc off before the ArcOK was issued.

Well from what I saw in its present format as coded, this feature is not usable if you have an arcOK signal as you can't go shorter than this time frame and on my machine thats a pretty big divot.

I'm sorry my cool idea wasted Phill's time.

I Agree there is a lot of unknown latency in the system once the spindle on signal is enabled. I think some halscope plots are in order.

I started to write a separate component today that commenced the timer when the arc was sensed by my hypersensing component. My torch on relay turns off in 2 usec so any latency will be in the machine.

I do know somebody who had great success using current to set an ArcOK signal and also for spotting. But he hacked his machine, added a current sensor and built and programmed his own external THC using a microprocessor.