Hand held rechargeable foam cutter

thingiverse

I wanted a compact battery-powered hot-wire foam cutter. I had plenty of spare Li-ion 18650 cells on hand, so I decided to design one using 123D Design. This cutter uses a TP4056 Li-ion single cell charge and low voltage protection board, an 18650 sized Li-ion cell, a 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 protruding from the base. The bends on the end to hold the nichrome wire are located 1 and 2 cm from the end. I've found that I prefer using 28 awg nichrome for moderate cutting speed and foam loss. I start with a piece of wire 9.25 inches long, then mark about two inches from each end. Next, I wrap the wire twice around a 3mm rod with the mark at the beginning of the first wrap and twist to secure. This should result in a cutting wire approximately 5.25 inches long.