A hot wire cutter for expanded Polystyrene and Styrofoam is very easy to make it only requires very simple tooling.
Requirements
Wooden strips to form a frame good size being 8mm x 40mm approx total length 1.5M
2 x M4 or M6 nuts and bolts x 20mm long.
2 x M3 Wing Nuts.
4 x M3 Washers.
2 x M3 Bolts x15mm long.
0.5M strong elastic.
Resistance / Nichrome wire available from Maplin, Farnell, RS and alike.
2 core electrical wire
Method is as follows, Cut the wooden strips into 3 lengths.
Drill 4 or 6mm holes 2/3 of the way along 2 pieces.(hole to match M4 or M6 bolts)
Drill 4 or 6mm holes at the ends of the other piece
Drill 3mm holes at the end closer to the 4 / 6mm holes in the first two pieces of wood.
Bolt the 3 pieces together to form a letter H using M4 / 6 bolts and nuts.
Put 2 M3 washers onto the M3 bolts pass through end holes.
Apply the 2 core electrical wire to the M3 bolts best to twist ends into loops and hold in place with wing nuts.
Apply elastic to opposite ends of uprights of the H to the M3 bolts.
Fix a length of Nichrome wire between 2 M3 washers on one end of the H.
Squeeze H to stretch elastic and fix other end of Nichrome wire between other 2 M3 washers, this will keep the wire taught as it gets hot (as it gets hot it expands(lenghtwise) quite a bit, it will shrink when cool)
Apply a 12 Volt source either a Car Battery or car battery charger are good at this and hey presto one hot wire carefull if you touch this it WILL burn!!!!
PICS TO COME SOON.