Temperature controlled knife.

[hzeller]

Right now, we have a hot wire that melts through the plastic. The wire is fairly low thermal mass, which means it cools down quickly when going through the material, and also requires changes e.g when there is a breeze due to working outside or a fan.

So instead of a simple wire, we should heat a flat piece of metal with a wire on it and a temperature sensor. The wire can be curled to work with common 12V supplies, so that we can have a single power supply with fairly low current to run it.

Maybe a copper plate sandwiched between two aluminum plates heated with wires on both sides (insulated with e.g. Capton ); ⌇ represents the heating wire layer here:

|⌇|⌇|   <-  AL-capton-heating-capton-CU-capton-heating-capton-AL
|⌇|⌇|
  |     <- CU (copper)

Temperature sensor is cemented in a central place.

The control circuit could actually be a re-purposed 3D printer board, which already has temperature sensor input.

Advantages: independent of airflow conditions, less heat-related expansion bending of wire; also we can control the temperature to exactly melting and not burning.