Summary

This is a simple plastic bender I made to form acrylic parts. There's not much to it, it's a flat platform with a groove to pass a nichrome heating wire through. There's an edge guide so the bends end up square if needed. The maximum bend width is about 14". 3D CAD files included from Solidworks 2010, not that there's much to them!

Instructions

Some notes -

I designed the parts to be laser-cut by Ponoko, so the parts are formatted to their P3 size sheet. I used the US Ponoko hub's .251" MDF.
There are small grooves engraved in the parts to make the anchor hole for the steel springs that hold the heating wire, match them up when gluing together.
4 small wood screws hold the guide on.
Use the PDF pattern to bend 2 springs.
Bend small loops in the ends of the nichrome wire 17" apart. That should let the springs keep some tension in the nichrome to keep it straight.
I used 1/8" R/C airplane wheel collars to clamp my lead wires to the nichrome.
Be sure to insulate the groove to keep the MDF from burning; a strip of aluminum foil and some Kapton tape should work.
Any power supply used for hot wire foam cutters should work (12V, DC or AC doesn't matter, up to 10A). DIY designs are all over the web.

Plastic Bender