Plasma table stopping cut midway

Metal Shop
#1

Hi,

Thanks @TBJK for replacing the relay yesterday, which allowed the machine to proceed past the initial start phase to start the machine.

Yesterday, I tried to use the machine again. The ohmic sensor error did not go off. But now, it will proceed to cut my job, but midway through the cut (between 2 and 5 seconds after starting), the machine stops moving along its axes. The torch remained on for an indefinite amount of time, and stopping the run via computer would not turn it off. This is the first time I had to effectively use the emergency stop button. Below are some notes:

  • I was using a member’s fine tip nozzle. I did not try the standard tip.
  • I tried two thicknesses of metal, 8GA and 24GA. Both mild steel.
  • On one cut, we noticed that when the machine stopped, it would run itself downward and press into the material.
  • As the torch remained on and immobile, it cut a small hole in one of the slats.

Thanks for your help @Team_Metal_Shop

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#2

It’s having issues sensing the metal. I’ve had this happen when cutting thick materials (1/4") and having 2 cuts run into each other. Where one arc went to the left “)” and a cut of another letter bent to the right “(” and the were right next to each other “)(” the torch would lose sense of where the height was and it would drop down onto the material.

Space out your cuts if you can.

#3

Interesting. I’ll try again. Maybe I need to recreate my design/tool paths.

I was only making one cut and it was not very intricate. Think of something like this

image

#4

I will be there this afternoon. When I ran it yesterday I didn’t have issues. However I only did a 1.5” circle. I did physically check all the grounds but I did not do the test on them to see it the ground resistance was getting high, that can cause height control issues.

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#5

That almost sounds like it has stopped receiving G-commands from the computer.

Tim, think maybe there’s some dust in the connectors of the fiber?

#6

I don’t think so. I feel we would have a com’s drop if that were the case. Its possible though.

@nacho How big dimensionally was it?

#7

About 7x4"

I can show you how the cuts ran if we’re at the Space this afternoon.

#8

save off a copy of the G code as well so we can take a look at it.

The more we can get to reproduce the problem the better we will be able to diagnose them.

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#9

Came in just now and a member is using it flawlessly. not sure what has changed, but I’ll try again after hes done

#10

I saw @Trent_T using it when I got here on some thin sheet metal making some signs. I watched a couple of them be made.

#11

So I found a few things. I did not accept some changes last night. Then on the fine cut we found some discrepancies in the Fine Cut Chart. They are actually are quite a bit of difference. I will be looking over the CSV file which the charts reside.

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