Trouble cutting 1/4" with plasma / plasmacam

[sflraver]

I am having a bit of trouble cutting 1/4" mild steel plate on a plasmacam table . This is what I have:
Miller ICE-40
Power: 40 amps
Speed: 40ipm
Cut height: .08"
Pierce height: .11"
Pierce time: 1.2 (sec)
DHC - ON

What is happening is that it will cut perfectly part of the way then it will start not pushing through the plate. It is piercing just fine and I have the time turned down to what I feel is the minimum pierce time.
I have tried speeding up and slowing down the cut speed but it is no help.
I have a water collector at the air compressor and one at the plasma cutter.
What seems to be happening is when it starts not pushing through the plate is that the DHC starts lifting the torch. Any idea what to look at next to get the problem corrected?

[Jcar]

I'd double check my electrode and nozzle, and make sure I'm getting good contact with my ground clamp.

[sflraver]

Thats the thing.. switched out tip and electrode. Still getting the same result. Ground strap was checked as well.

For instance what will happening is that I am cutting a 2" circle. The first 90 is not going throught the sheet.. the second 90 is percect, the third is not going through again and the last 90 is perfect.

[sflraver]

Ok, got the problem figured out for the torch not cutting through all the way. The settings on the THC were all messed up. That solved, now I am cutting through all the way but I am back to the problem of the huge bevel on the cut.
(this seems to be caused by) I can put a new tip in and it seems to immediately elongate the hole in the tip, thus it starts cutting a huge bevel on some angels of the cut.
Does anyone have good settings for pierce , pierce time, pierce height, cut height and cut ipm for cutting 1/4" mild steel at 40 amps with a Miller ICE-40? My current settings are a few posts up. Any ideas what to change next?

[Jcar]

I usually pierce a little higher at around .160 and cut at about .080 (thc dependent). I think my pierce time is around .7 seconds. This is with a Hypertherm Powermax 1000 running at 40 amps.

[jpmassey]

I had an ICE-50 Torch. I found that it cut fine, but the tips wore way too fast, resulting in a beveled cut. As a hand torch its fine, but doesn't produce an accurate cut for longer than a few minutes for a cnc machine.
I sold it and bought a hypertherm. As long as I don't touch the tip to the metal on the hypertherm torch, they last alot longer. I cut at 80 amps, and the quality is still not always perfect. There will always be a bevel, which will change depending on the direction the torch is moving.