Hot wire bender V1

Filed under: prototyping tools

Hot wire bender V1

Building small prototypes out of plastic sheet is one of the quickest and easiest ways to create boxes, enclosures etc. This small hot wire bender is capable of bending 2 to 3mm acrylic sheets. The temperature can be controlled using a small knob on the front and the height of the wires can be adjusted manually to ensure correct heating.


The electric calculations for this project are simple but they contain multiple variables. The first limiting factor is the power supply / regulator. I chose a 24V power supply with a regulator that can handle up to 3Amps. More powerfull options are available online but testing has shown that 3Amps is enough for this application.

The design of the hot wire bender requires aprox. 1 meter of NiChrome wire. Knowing that we have 3A at 24V we can conclude that the wire should be around 8Ohm / Meter. This can be achieved with a #26 gauge (0.406mm) Wire.


The electronics consist of

- 1 meter resistance wire #26 / 0.406 mm (8 Ohm / Meter)

- 2 ceramic screw terminals

- 1 Adjustable power regulator ( DC6V - 28V 3A)

- 24V power supply with a minimum of 3Amp

BOM & Schematic

My orignal plan was to publish the BOM and the electrical schematic so anybody could build their own wire bender. The build process has shown that the current design is not simple enough to release. A redesign based on standard aluminium tubing and 3d Printed parts is currently in development. This version will be published with all the details so anybody can build their own wire bender.