After Ben’s suggestion and some pricing on the web I went with Surplustronics after all. Picked up a 9v/1000ma AC adaptor for $20. They had some dodgy looking old Sega 10v/1000ma adaptors for half that price but I thought I’d splash out. At least the $20 adaptor came in a snappy blue and white box.
The gruntier adaptor does the trick. The wire heats up quickly and easily melts through polystyrene. After some experimentation I realised I hadn’t quite made my first wire cutter large enough. So I jigsawed up some more 5mm MDF and created the mark II which has a much wider armature. Here’s the mark I and mark II with a 25mm Zombie for scale.
Then I took to some old packing polystyrene and experimented. I carved a kind of half height hill and megalith then a little cliff face before I fled the garage and the stink of melted polystyrene.
So for the grand total of $22.95 I have a useable cutter – want one Griff? That’s:
- $2.95 : 4 metres of ni-chrome wire from Dick Smith.
- $20 : 9v AC adaptor from Surplustronics.
I’ve discovered a couple of things:
- Melted polystyrene sure stinks. Will crack open the garage door a bit next time I think.
- The heat cures the rough surface of even cheap polystyrene quite nicely. Gives it a smooth finish that hopefully will be resistant to chipping.
- I see why most store-bought cutters are based around a metal arm. This is to keep tension on the wire as it naturally expands with heat. This leads to a bit of slack in my crude home made cutter, but it’s not a big problem. Possibly a mark III built around a coat hanger?
- I wonder how long it’ll take before the AC adaptor dies? It certainly seems to warm up rather quickly. Possibly best to keep cutting times as short as possible.
Right I suspect a trip to Plastic Box this weekend might be in order. I think they’ve even marked down their big sheets of thick polystyrene recently.
Hey is the adapter AC/AC or AC/DC? I might be able to make it do double-duty because I think I need an AC/AC adapter to drive the points on my N Scale train layout.
Just a cheapo AC/DC adapter, I guess AC/AC would work just as well though wouldn’t it? The ni-chrome is just high resistance wire after all so it’ll heat up either way surely?
Can’t say I’d want to use a decent adapter to make a hot wire cutter like this though because it’s a bit shady (my adapter tends to warm up a fair amount too).
[...] but am nearing the time when I can commit a layout to glue. I will need a hot-wire cutter (which Stu kindly reminded me about) to start sculpting the required shapes (ramps, a mountain with a tunnel, and a small stream) from [...]