[big iron]

I have two Hypertherm 1000 G-3 Plasma generators with M-60 machine torches operating on Dyna Torch CNC cutting tables.
On the one particular machine I am having problems with we have installed Dyna Torches DASH no touch system. I am using Hypertherm Fine cut consumables and always have.
These two machines cut 14 and 12 Ga Laser quality carbon steel only, zero rust near mirror finish.
Problem I am having with the one machine is that it experances a no fire situation about one in every 4 to 20 pierces. The CNC will issue a G-23 code to fire the plasma the torch will travel down and the plasma generator will vent it's system pressure like always just before firing, however the plasma will not fire and then after 5 seconds the CNC controler will issue a falure to fire after 5 seconds code and ask if you would like to retry? The plasma will always re-fire after pressing retry. I have tried increasing the falure set time out to 10 seconds with no change in operation.
We have noticed that when the no fire occurs the Plasma generator will display a power on green lamp and the red fault lamp (not flashing) for a few seconds and then the fault lamp will go off. In the service manual this indicates stuck or jamed consumables. We have replaced all the consumables as well as the swirl ring and sheld cap many times, we only install the sheld cap finger tight as per instructions, and have tried different tightness.
Problem still there. we pulled the main torch body out and checked it for jamming and plunger movement as well as internal power cable jaming all seemed just fine. Put unit back into service problem still occurs, order new main torch body from Hypertherm P.N 3099839 and install nothing has changed still has miss fireing. It's not a over heating consumable problem
as this will occur sometimes in the first 2 minutes of operation in the morning after being off all night. The other 1000 G-3 is preforming the same cuts on the same material all day with no problems as well as a older Hypertherm 900 with a machine torch. The only differance is that the DASH system takes a little longer to locate it's pierce point. all three are on the same compressed air system with a state of the art air drying system set at 80 p.s.i.g. The only differance between the two 1000s are the one with the starting problem has the Dyna Torch DASH system installed on it, we where trying it out before purchasing for the other two machines.
These machines operate at 40 amps, 80 volts ,135 IPM with the cycle times and amperage we cannot be getting near exceeding there duty cycles.The little 900 been preforming this job for over 6 years.

Any help in what direction we should be checking would be greatly appreciated.

[jimcolt]

Very good detailed report......from what you have written, I would swap the plasma systems from one machine to the other. You could actually first swap just power supplies......if that made no difference then swap the torches and leads. There are a few things I can think of that may give these symptoms:

1. If the problem stays with the machine (does not follow the plasma)....then there may be some type of plasma start signal "bounce" that could be caused by electrical noise from the plasma power supply initial inrush current. You could trouble shoot this by jumpering the input start to the plasma instead of letting the Dynatorch output for the plasma.

2. If the problem goes with the torch (but not the power supply).....there could be either a restriction or a leak between the power supply and the torch that is causing an abnormally slow air pressure increase to the torch.....this air pressure is used to pull the electrode away from the nozzle....which creates the spark for ionization of the plasma gas.

3. If the problem seems to go with the power supply.....there could be a bad (sluggish) air flow solenoid.....or a leak (or restriction) in the internal air plumbing.

4. Missing or leaky torch body o-ring.


Usually a misfiring Hypertherm Powermax torch is caused by a. overtightening of retaining cap. b. defective or worn retainaing cap. c. aftermarket consumables (tolerance issues, usually from American Torch Tip parts) d. defective or worn swirl ring e. high moisture or oil content in air.

Let me know if I can help in any way....also, have you worked with Hypertherm's tech service? They are usually very helpful....and free!

Best regards, Jim Colt Hypertherm

[big iron]

Hi Jim, will try swaping out machines / torches and see what happens. One odd point is the problem seemed to increase after the addition of the Dyna Torch DASH system? Although I dont know why it should. The machine takes a few seconds longer now with the DASH system to fire then before as it seeks torch height and then firing location. We where going to turn the DASH system off today and see if that made any difference as well. Thanks for your help , Mike.

[jimcolt]

As I said.....it is possible that line voltage hash/electrical noise from the plasma may be bouncing the start signal.....which the Dash system likely has control of. Once the problem is isolated we'll have a better handle......could well be a software controlled setting (some have "debounce" settings to deal with electrical noise)...from the Dynatorch end.....either way, it will be nice to know what is causing the issue.

Jim

[big iron]

Well here's what we have came up with so far; after changing the entire M-60 machine torch we still had a high rate of falure to fire in 5 seconds stops.
Next step was to swap out the plasma generator, same machine Hypertherm 1000G-3, original machine torch reinstalled ,problem still there. As stated in previous link we are using a Dyna Torch DASH system on this cutting table.
The DASH system is new and after we shut down the DASH system the falure to fire problem went away. We ran over 250 pierces with no problems then we turned the DASH back on.
The interesting thing is when we turned the DASH back on it crashed the torch about 1 in 10 pierces, distroying 3 sets of consumables in less then 1 hour, it never did this before, just the falure to fire problem. We recalibrated the DASH two times but both problems are there now.
We are currently running the machine without the DASH system. As before we are only cutting 14 and 12 ga laser quality carbon steel, near mirror finish. Nothing else has changed however the DASH appears to be degrading in it's operation, it's eye is clean and it's eye protection door works correctly.
The setup is correct to Dyna Torch specs.
I have contacted Dyna Torch tech and they said that the DASH unit could not be affecting the starting arc as it issues a start arc G23 code only after it finds it pierce height.The falure to fire in 5 seconds does not occur when the torch crashes, seems to be two different problems with the DASH.
I am wondering about the DASH controller.