ACoC 2014: Day 7: Variable Capacitor

Here are the files for the frame of the variable capacitor shown in this video. This is still very much work in progress, but it might be useful for someone. You need all three files (below), two of them are t-slot and M3 hardware libraries I tend to use for this kind of laser-cut project.

One thing I failed to mention in the video is the trick for soldering to Aluminium tape. You can tin Aluminium with normal 60:40 electrical solder by using normal candle wax or a similar flux. Melt a small pool of wax over the spot you want to tin, then rub solder on it under the wax until it tins. It may take a while (and a lot of heat because Aluminium is so thermally conductive), but eventually you'll get through the oxide layer in one spot and you can then spread the tinned spot out with more rubbing and solder + flux.

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title type size
OpenSCAD file for capacitor frame box. application/octet-stream 2.118 kbytes
A T-Slot library of sorts. application/octet-stream 2.313 kbytes
M3 hardware geometry include. application/octet-stream 147.000 bytes

Parent article: Advent Calendar of Circuits 2014.