Hot wire cutter from scraps

Hot wire cutters are quite expensive.

Well…. relatively expensive. I mean, at least… thirty quid or so, with a cutting table. So not really that expensive. But I guess I’m just a bit stingy. Because I couldn’t justify it to myself, knowing I had everything to make one out of left-over scraps.

Essentially, they’re just a wire with an electric current running through it, which makes it act like a little heater and get really hot.

After an hour or so with Inkscape, I had a sort-of idea about how it would work out. A simple table with an adjustable stand for the wire seemed like an acheivable design for a one-day build.

(of course, like @warzan making a 3d HeroQuest board, it was soon to spiral out of control, but a one-day build felt possible at the outset).

My own laser cutter is knocking on a bit now, and probably in need of a new tube, so I popped along to my local hackspace (BuildBrighton) and used their large-format laser cutter to make a frame to hold the hot wire.

After gluing it all together and leaving for a few hours, I ran some wires inside the three layered construction and clamped them to the rings at each end using M3 bolts and washers.

At this stage, I was tempted to just connect the wires up to a 9v/12v power source and see how hot the wire got. But I was using some relatively thin 32AWG vape coil wire and had no idea how hot it could get before breaking.

I thought it prudent to knock together a quick power-controller, to be able to vary the voltage through the wire (so I could quickly kill the power if the wire got too hot!)

Using an Arduino, an LCD and a linear potentiometer, I made a variable controller using an IRF640 power FET and PWM output on one of the pins.

Amazingly, the cutter worked first time!