Just got my KNK Force a few days ago and so far I really like it. I tried cutting some very thin Lexan (.03″) and am seeing some strange behavior. I recorded it in this video. The weird action starts at about 1:04.
I’m using the following settings: Blue blade (brand new), BT: 3, CD: 10, CS: 10, US: 20, PS: 30, LS: 40
Here’s the strange thing. It seems like it can cut through the material just fine, even at a higher cutting depth and cutting speed, until it moves at a particular angle. If you look at the video you can see the behavior is very consistent across a half dozen attempts with various settings. It always fails at the last point of the star.
I also tried a different file (just the letter “A”) and saw the same thing. It works fine until the blade moves in that one direction.
Any advice as to what the problem could be or what I could do differently?
Cutting polycarbonate is not a recommended task to perform with a blade. The jumping and stuttering is the motor being unable to move the tool holder when the blade gets stuck the material. Be wary of that when cutting anything as it has potential to damage your machine.
Other users do this type of cutting with the rotary tool and a bit appropriate for acrylic/plastics. Generally speaking, standard acrylics cut more readily than polycarbonate/Lexan.
A good litmus test for blade cutting is “Could I do this with a steady hand and an X-Acto knife?”