[N2950H]

I recently used my CNC plasma to cut some shapes out of 0.125" aluminum and I have some pretty good warpage going on. Most of what I've done so far is steel, so cutting aluminum is new to me.

I'm following the cut chart for my Hypertherm 45 (with some interpolation). The chart calls for 220ipm on 10ga and 280 on 12ga. Since I'm in the middle, I went with 250ipm. I'm basically cutting out a square frame with lots of shapes being cut out of the middle. I've considered upping the cut speed to see if that helps, but I'm afraid of losing the finer details of the design if I do that. It also concerns me to stray too far from the recommended values as doing that is typically a band-aid for some other issue.

Another thought I've had is pausing the program after each of the ~25 internal cuts to let the aluminum cool back down between shapes. While this might work, it doesn't seem like a very good solution for someone interested in production rate.

I am using a water table but the water level is a good .5 - .75" below the work piece...something I intend to change with my next design.

Any thoughts would be greatly appreciated.

[jimcolt]

Sounds like you are simply building up too much heat with the inside cutouts. If you are cutting multiple parts......cut a few inside paths on one, sthen skip to others and allow the temperature to stabilize, then go back and do more. There are some CAM software solutions that will do cut path order based on thermal input, or you can set the cut paths manually. Faster cutting is better, or figure out a way to have the parts partially submerged in water.

Jim Colt Hypertherm