Also keep in mind if you get to an edge sometimes the air coming out of the tip will wiggle the material to make it look like a jagged cut. You could try dropping your amperage and cutting slower to see if there is a change. But at 75 tip volts something is wrong as you should be well over 120 tip volts. You probly have the division wrong in your plasma cutter and PWM box. Do you know how to check? The plasma cutters usually ship at 50-1 ratio and the PWM boxes can go out either 7-1 or 20-1 so that would explain the tip voltage issue. To check uscrew the 4 screws from the bottom of the black box and take the cap off and not where the jumper is sitting. There are instructions on your support disk for that as well. Make sure the CPC card in your Hypertherm and the black box are using the same division. You may just have to move the jumper. The best division is 20-1 this gives the most accurate THC next to Hypertherms Hydef. Make sure the CPC in the plasma cutter is set to 20-1 and the PWM is set to 20-1.