[Francisco] is helping his mother with a repair to the headlight knob on her Ford Ranger. Above you can see the broken knob on the left, and what it is supposed to look like on the right (taken from [Francisco's] own vehicle for reference). We’ve encountered split shafts on plastic knobs before and decided it was not something that could be fixed. But he didn’t give up so easily. He mentions that you can purchase a replacement for a few bucks, but he has the means to repair the knob by machining a metal bushing.

The idea is that you mill a metal ring whose inner diameter matches what the outer diameter of the plastic shaft should be. By inserting the broken knob in the ring, the plastic is held tightly together as if it had never broken. In the video after the break [Francisco] uses a metal pencil body from his junk box and a mini-lathe to cut the bushing to length, and mill the inner diameter to his specifications.

He talks about the difficulty of getting replacement parts in Chile, where he lives. But we think this kind of thrift is a great example for all hackers. If you’ve got the tools why not use them? And if you don’t have them, here’s a great excuse to procure them!

A sensor board, placed behind the display, picks up the signals from the inputs. The only limitation to the number of inputs available is the size of your screen. Inputs are held on magnetically, and have a low friction backing to avoid scratching or gouging your screen.

Here is a demo video showing use with one knob. It doesn’t appear to slip or slide at all while they are turning it. We’d love to play with it a little bit and see what it is like, as well as see more information on what technology is being used.

[via Music Thing]