An acrylic spring clip

Last week I started on the fixture that holds I²CMini while it's having its unique ID code laser etched on the back. 

Looking a bit closer, there's a little bit of wobble in the lettering.


I think some of this wobble is the I²CMini itself moving around in the fixture as the laser etches the glyphs. Thinking about this mechanical problem, the first idea was some sort of spring clip to hold the piece in place. But then insight struck and I realized that the spring clip can be cut into the acrylic itself! Here's the idea:


It's a very simple mechanism. The top clip gets pushed up a little when the I²CMini is inserted, holding it down into the frame. After tuning for the size of the displacement, the single-unit version looks like this


Having confirmed the idea, yesterday I put it in a for() loop and cut the 50-unit version for production:


It's all set. One happy side-effect is that all the parts are now held securely in the tray, preventing annoying spills on the way between the test station and the laser etching.



The topic of mechanical components made from laser-cut acrylic doesn't seem to be much explored. If there was a book of "100 Useful Mechanisms in Laser-Cut Acrylic" I'd buy it in an instant, but there's not much out there. The closest I could find is a 2013 Hackaday post on acrylic spring clips, linking to a now-defunct blog. If anyone knows of a good source for similar techniques, please let me know!

Thanks for reading.