I needed some foam cut to cradle a part we make, essentially a custom fit foam box liner. I tried cutting 1" thick EPS, the white stuff I buy in sheets and use my hotwire cutter on. I also had some "cushy" grey foam that is not rigid like the EPS. I have a few questions.... first, everything was a guess on power and speed, so I ended up at 100% power (50 watt machine), speed was about 10% and 250PPI. Does pretty well on the grey foam, but on the EPS it cuts pretty close to on the line at the top surface, but tends to get a lot of melted kerf and sideways blow out by the time it gets through the 1" EPS.
I played with focusing a little higher, or lower, didn't seem to have any better results. Would I have better luck at less power and dramatically slower speeds, say maybe I drop to 50%-60% but speeds down closer to 1% or less?
Also, I had issues with consistent depth cutting. At a power level and speed that would get all the way through in the curves, the straight bottom cut and slightly tapered top cut, where the carriage moves much faster, were not cutting all the way through, like maybe 75%. I assumed when you set a speed the controller would make it move that speed along the full path, not dramatically faster on straight lines and a lot slower on any curves. I suppose I can change colors on the two straight lines and hit them with less speed/more power, but it just seemed odd that it would be that different.
IMG_1247.jpg