Any way to limit warping on thin material ???

[flyinwilly]

Getting ready to head back north and take the wraps off the plasma table. Been thinking about ways to limit warping on 16-18 ga sheets with a lot of cuts. The THC does a great job of maintaining the distance during the cut but the warping is still a pain in the butt.

I've been thinking about using a small pump to flood the top of the plate with quench from the water table which should cool the plate down quite a bit and hopefully prevent a lot of the warping. I could hook the hose up to the floating head so it would follow the torch.

The question I have is the electrical part. With the water flow basically aimed towards the torch discharge, is there a danger of an electrical charge going back to the pump and its power supply or is the workpiece ground always the path of least resistance ??

As usual, any help appreciated.

Willy

[jimcolt]

You don't mention what plasma system you have.

If you have a system with a choice of different consumables...such as a Hypertherm Powermax....use the smallest nozzle size (FineCut) at near its maximum rated amperage, at the fastest possible cut speeds (your machine acceleration should be at its maximum capability as well). This will minimize warpage.

Your method with water will minimize warpage, but on most materials will cause a rougher cut edge and more dross formation.

Jim Colt Hypertherm

[flyinwilly]

I currently use a Cut40 (chinese) but am getting ready to order a PMAX 65 because I have to start cutting parts from 1/2" mild steel and the cut40 is underpowered and the cut is not that good on thicker material.

I understand about running at the maximum speed you can with the fine cut consumables but the things I currently do have a lot of turns and the machine is constantly accelerating and decelerating so it really never gets to the max feed rate. This is why I was looking at the water to help minimize warping.

The question remains on the electrical safety of this idea. Is the pump (and me) going to be safe with the water squirting over the workpiece ??

Thanks,

Willy

[jcc3inc]

Sir,

We had one customer on the west coast who was cutting thin SS. He had a water table where the water depth just covered the top of the sheet when it was in position to cut. When the cycle started and the gas flowed out of the tip, the gas moved the water away from the area immediately under the tip and then the cutting progressed. It appeared to me that there was no warpage as water cooled the area immediately after the cut.

Regards,
Jack C.