Hand held rechargeable foam cutter

thingiverse

I wanted a small(ish) battery powered hot-wire foam cutter. I had plenty of spare Li-ion 18650 cells laying around so I decided to spin one up in 123D Design. This cutter uses a TP4056 Li-ion single cell charge and low voltage protection board, 18650 sized Li-ion cell, 6mm square momentary contact push button switch, 26 awg wire, and 1/16th inch music wire. The music wire is bent to match the grooves in the base, and then cut at the 6 inch mark sticking out of the base. The bends on the end to hold the nichrome wire are at 1 and 2 cm from the end. I have found that I like 28 awg nichrome for reasonable cutting speed and foam loss. I start with a piece 9.25 inches long, then mark about two inches from each end. Wrap the wire twice around a 3mm piece of rod with the mark at the start of the first wrap and then twist to secure. You should end up with a cutting wire that is about 5.25 inches long.