Holiday/Christmas themed DIY light show projector. Not sure if there is a better name for this, but you can project any image that can be printed as holes on the slide.

The way it works is you stick all the pieces together with one of the design slides sandwiched between the projector body and the mirror housing, and then the flashlight shines through the mirrors, through the slide, through the two lenses in the projector body, and the image is projected onto the wall. More distance to the wall = larger and clearer image.

I created 3 slides which you can swap out - the Merry Christmas design, the Happy Holidays design, and Santa's Sleigh - santas sleigh is the worst result print-wise, so you may just want to skip that one. The other two turned out fine with only small details lost.

Feel free to remix this/make your own custom slides using the ones I have uploaded as examples, here are the dimensions for the slides:
Slide size: 80x80mm
Design area: 47.5x47.5mm (centered)
Slide thickness: 3mm

Projector Body is 80x80x173.5mm
Length of assembled projector is ~165mm
Height of assembled projector is ~128mm

-

This project requires a few non-3D printed parts, including:

~$10-20-A bright flashlight with a tight beam (I used an LED one which is no longer for sale)

$24.99-Slide Viewer (for the lenses - I had one already which was the inspiration for this project) - example - https://www.amazon.com/MAFUEAY-Negative-Lighted-Illuminated-Magnification/dp/B0C13N2PS1/ref=sr_1_9?keywords=35mm+Slide+and+Film+Viewer&sr=8-9

$3.99-Square folding 1x/2x compact mirror - https://www.amazon.com/dp/B0BC25YPR9?psc=1&ref=ppx_yo2ov_dt_b_product_details

All parts were printed in PLA, and no supports are needed for any of the parts. Your printer needs to be relatively dialed in to get the image slides precisely right, there are a lot of fine details, but mine isn't perfect, and I think the somewhat ragged look is a cool effect anyways...

This is all custom designed, it was a gift for a friend but I think it turned out pretty cool after several revisions, and I figured others might be able to take this idea further, create more slides, etc. - Colored light filters? A slide module which holds actual slides and lets this project color images onto the wall?

You can also just attach the flashlight or light source directly to the projector body if you don't want to deal with mirrors, it will make the projector considerably longer, I added the mirrors to be able to mount the flashlight on top to position it on top of a narrow bookshelf, but they are not needed if length isn't a concern..