This puzzle is really hard to solve! It took us a few hours over the course of a couple of days to find our first solution. Don't look at the third image if you don't want a spoiler. There are tons of other solutions you can find, though. That doesn't mean it'll be easy! We learned about this kind of puzzle from a recent Stand Up Maths video on YouTube, currently titled "The impossible puzzle with over a million solutions!". In the video Matt Parker made a 9x9 version in honor of 2025 (which my son liked because he's 9 this year) but we made ours 8x8 to fit on our build plate without having the 1x1 tile be too small.

For each size tile, you need that many of them. So you need eight of tile 8, and so on down to just one tile 1. The frame doesn't have any clearance built in. It worked okay on our printer, but the tiles do kinda buckle up just a little in some configurations. You should be able to just scale the frame up a tiny bit if you're worried about it.

My son and I worked together on this, but he did all of the designing himself in Onshape!