PROJECTS: ST YRO CU T TER

makezine.com/16/styrocutter

THE CUTTING EDGE EPS is a thermoplastic foam that can be cut with a hot wire like a warm knife through butter.

You can buy expensive, commercially made hot-wire cutters, but I’ll show you how to build a super-simple DIY design quickly for next to nothing, and how to get great results with some clever accessories and foolproof techniques.

For the cutting wire, this design uses a fine wire made of nichrome (nickel-chromium). It’s held vertically on a table and kept taut by a bent aluminum arm. A model train transformer is used to convert AC power into a controllable and safe 12 volts DC. As the current passes through the wire, it warms up. This design lets you guide the pieces of foam into the stationary wire and slide the foam around to make effortless cuts.

HOT-WIRE CUTTER EXPOSED

This cross-section view shows how the conductive aluminum rod completes the circuit to provide current to the nichrome wire.

To make perfect cuts, use cutout cardboard shapes as templates.

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1 Nichrome wire
2 Aluminum rod
3 2× 4 base
4 Wire anchor
5 Pegboard
6 Red test lead — positive
7 Green test lead — negative
8 Transformer
9 EPS foam

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Illustration by Bill Oetinger

116 Make: Volume 16