aluminum plate warping

[gamble]

There are a few things I cut that I can't seem to keep them from warping.
The plate is 5052 .100 aluminum. Powermac 45 at 28amps and 150IPM (used to cut at 120IPM but tried 150 and still warps)
I have this on a water table also
So this is the piece I'm cutting


So I let it cut all the letters first then stopped it and let the post flow run and let the plate sit there and cool for a few minutes. Did some more cutting and let it cool for a few minutes. The one line under the boxes, that cut alone will make the plate warp. I have no idea on how to make the plasma just cut the one direction without coming back to the starting point. I have to chase the plasma arc with a bottle of water on the piece to keep the warping from happening and even then it still has some warpage.
I think I cut 4 of these today trying different methods and can't find the right solution.

I also do not have height control, but I can't see that helping me here.

[Shane Warnick]

According to your cut charts you should be at 45 amps and 280-360 IPM. I would give that a swizzle unless your machine isn't stable at those higher speeds.

Shane

[jimcolt]

You are cutting way too slow....follow the recommendations in your cut charts and the warpage will be minimized.

Jim Colt Hypertherm

[gamble]

You are cutting way too slow....follow the recommendations in your cut charts and the warpage will be minimized.

Jim Colt Hypertherm

I wish I could. But the torchmate is limited to only 150ipm. Even the new setup with acccumove2 is limited to 200ipm.
Any other recommendations?

[cpreston]

Take a garden hose and run cold water across the top of it. Also I think I am at 24 amps

[Shane Warnick]

If you can't go faster, you are going to have to change the drawing to minimize warping. Break those long slots into 2 or 3 shorter ones, and cool the plate between cuts. More than just what will be accomplished with post flow air. Water, etc. If you can't go faster, it's going to warp. That's just one of the drawbacks of that material. Only other option would be try thicker material. Maybe some 3/16" diamond plate or smooth aluminum.

Shane

[vmax549]

Here I cut aluminum about 70% of the time. YES aluminum has a HIGH expansion rate. Under heat it can warp out of shape. It can also set temper very Quick(Squirting water on it). Doing so it makes matters worse. You set teh temp and the aluminum cannot contract back to where it started from and it will warp even further.

The best advice is to cut it with a GOOD thc control that can follow the warpage and still cut well. THEN let it cool back down on its own BEFORE you touch it. 90% of the time when it cools it all pulls BACK into place and the warpage is gone.

It is worse on LARGE straight cuts that are thin in cross section.( nothing to help restrain the expansion) BUT if you do not distort the temper it will contract right back from where it started from.

(;-) TP

[gamble]

I don't have a thc So i just set it to a height that will work across the board and let it cut. The middle of the table is taller for some reason and I'm not sure why.

So i do pour water on the steel that has a lot of detail and let it wait a few minutes inbetween cuts if I don't have water. That seems to work but it's not a great solution.
For the aluminum I did what you said and just let it sit. So that piece above or similar I'll cut the inside out and stop the machine and let it sit for a few minutes then I'll cut the outside.
For some reason lately pieces that normally never would warp are warping pretty bad. But I did what you said about letting it cool on it's own. I will stop the machine at the end so the torch doesn't go over it again and the air doesn't disturb the piece and just let it sit for a few minutes. When I come back it's pretty damn flat.
Now I haven't done those pieces that tend to warp a lot, but I will and see what happens.
Thanks for the help