Cutmaster 42 Fires without trigger activated

[donniem70]

Hello all.
I have pulled my CNC Plasma table out of storage and I am having some issues.
I think I have most of my controller issues and such worked out. Been working on post processors and think I have those mostly sorted.
When I hooked up air to my plasma, of course the air lines inside the machine started leaking. I replaced all those. Now thinking I has most evey thing sorted I decided to to give it a live run. As soon as my the torch tip touches the work piece it fires. I stopped everything ( Thank goodness for the newly added E-Stop button). I check all my wiring again and everything looks correct. I turned on the Plasma and lowered the z-axis, as soon as it touches the work piece it fires. Not running any g-code, just lowering the z-axis until the tip touches. I unhooked the switch trigger wiring and tried again. It still fires. I have checked the trigger wiring going into the Plasma and I am not finding any shorts anywhere.
Anyone have any ideas on what to check next?
I am running a Thermal Dynamics Cutmaster 42. I am running a Gecko G540 controller with Mach3 software.
This setup use to run well, before it was put into storage.

[acourtjester]

Are you using a floating head switch or ohmic sensor, if so I would check the connection for those. If they have switched inputs to the controller that could fire the torch.

[donniem70]

Are you using a floating head switch or ohmic sensor, if so I would check the connection for those. If they have switched inputs to the controller that could fire the torch.

Thanks, I will look into that.
It is just odd that I have the plasma machine disconnected from the CNC controller and it still fires. There is nothing connected to the Cutmaster 42 to command it to start.
Could the start cartridge cause something like that? I have all new consumables in the torch, except for the start cartridge. But it has not been used many times.

[weldguy]

That is the strangest thing since it is not even connected to the controller. Don't see how the start cartridge could cause that.

Hand held or machine torch on this setup?

[acourtjester]

You may contact Tech support, for a clear answer for that unit. If it is not connected to anything that seems to be a good candidate, Could be some plasma dust got inside and shorted something.

[donniem70]

That is the strangest thing since it is not even connected to the controller. Don't see how the start cartridge could cause that.

Hand held or machine torch on this setup?

It is the handheld torch.

[weldguy]

That is odd. Have you taken the torch off off of the machine to see if it does it in your hand? Maybe it has something to do with how the torch is mounted to the machine, hose clamp shifted, handle squeezed too tight, cracked handle flexing under downward pressure, I have no idea what the setup looks like but I would try taking it out and see if it behaves the same.

[donniem70]

That is odd. Have you taken the torch off off of the machine to see if it does it in your hand? Maybe it has something to do with how the torch is mounted to the machine, hose clamp shifted, handle squeezed too tight, cracked handle flexing under downward pressure, I have no idea what the setup looks like but I would try taking it out and see if it behaves the same.

I took it out and it still does the same thing. When you start the machine, the air comes on for a few seconds and stops, as it always has. When it touches off to the work piece, it acts like something activates the trigger. The air starts and the torch ignites. As soon as I bring it off the work piece, the arch stops, the air runs though its post and stops. It is very strange.
I have modified the hand held torch, so it goes straight up, like a machine torch. But that was done years ago and I have run the machine many hours like that. I believe it is something inside the machine. I have found a shop manual for it with diag information. Going to check it out as soon as I get a chance.