Cutting the insulation off wire is something of an art form. If you’re not careful it’s easy to cut through the entire wire by accident. To solve this problem, Thingiverse user bjbsquared created a simple wire cutter that lights up when you cut through the insulation.To make this yourself, you only need a LED, a resistor, a couple of razor blades, batteries, and some screws. The guide also includes instructions for a 3D print of the board it’s attached to, but you don’t have to use a piece of 3D printed plastic. Any non-conductive material will work as long as you can cut it into the same dimensions.
Using it is very simple: move the wire into the blades to cut off the insulation, and when the light turns on, stop. If you’re the type to constantly cut all the way through wire on accident, it’s a great solution and the basic premise can probably be applied to tools you already have. Find the full guide to make one for yourself over on Thingiverse.