Collapsible Pattern Projector Is A Bright Idea

It’s fantastic that we’re living in the age of downloadable PDF patterns, it really is. But printing out a bunch of sheets of paper and taping them together is a tedious and tiresome process that can introduce error right from the start. This goes for any type of pattern, from sewing to R/C planes.

[Quinn]’s quarantine project is designed to cover both of those and everything in between. It’s a pattern projector made from stuff already on hand — a couple of offset projectors to scavenge parts from, and a large, trapezoidal mylar mirror from an old rear projection TV. At maximum zoom it projects a 4′ x 3′ image onto the tabletop, which sounds perfect for a whole lot of sewing patterns. At minimum zoom, the projected image fits on a foam core board.

We love that this dreamy setup can be stowed away so easily on hooks in the ceiling. [Quinn] had to perform a few hacks to make it all work together, including fabricating a bracket and some adjustable ties to hold the mirror aloft at just the right correct angle.

Need something smaller? Check out this Pi-powered pocket projector. Want a cinema-quality setup? You just have to find the right auctions.

Little Laser Light Show Is Cleverly Packaged, Cheap To Build

We’re suckers for any project that’s nicely packaged, but an added bonus is when most of the components can be sourced cheaply and locally. Such is the case for this little laser light show, housed in electrical boxes from the local home center and built with stuff you probably have in your junk bin.

When we first came across [replayreb]’s write-up and saw that he used hard drives in its construction, we assumed he used head galvanometers to drive the mirrors. As it turns out, he used that approach in an earlier project, but this time around, the hard drive only donated its platters for use as low mass, first surface mirrors. And rather than driving the mirrors with galvos, he chose plain old brushed DC motors. These have the significant advantage of being cheap and a perfect fit for 3/4″ EMT set-screw connectors, designed to connect thin-wall conduit, also known as electromechanical tubing, to electrical boxes and panels. The motors are mounted to the back and side of the box so their axes are 90° from each other, and the mirrors are constrained by small cable ties and set at 45°. The motors are driven directly by the left and right channels of a small audio amp, wiggling enough to create a decent light show from the laser module.

We especially like the fact that these boxes are cheap enough that you can build three with different color lasers. In that case, an obvious next step would be bandpass filters to split the signal into bass, midrange, and treble for that retro-modern light organ effect. Or maybe figuring out what audio signals you’d need to make this box into a laser sky display would be a good idea too.

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