If any of you have read my Air Boat
thread you saw that I have a nitro powered speed boat. Great fun until the engine dies way out in the water. I plan to remedy that by building a twin electric motored rescue boat. It will have two pontoons on it made from sytrofoam that will be covered with a layer of fiberglass. But in order to shape the styrofoam so that you get nice edges one needs a hotwire styrofoam cutter and that's what I built.
The whole write up is on my web site at http://www.kingstonemodeleng.com/MachineShop/foamcutter/foamcutter.htm
. I'll touch on the high lights here. If your interested in building one the details are on web site.
The table is made from a piece of tread mill. The wood is MDF and coated with some kind of plastic. Nice for the foam to slide on.
I built up an overhead arm out of wood and attached 1" aluminum angle plates.
The wire is .015" thick nichrome wire about 20 to 24 inches long. It is attached with home made fastners.
The power supply is out of a computer. I'm using the 12 volt supply. Here's it what it looks like cutting the foam.
And the cut pieces. Nice and smooth.
Later I found a 15 volt DC power supply and tried that. Works even better. Here's the temporary set up.
I use the aligator clip on the wire to adjust how hot the wire gets by moving the clip up and down on the wire. This set up will work for the rescue boat project. Later I plan to make this a bit more permanent.