I saw a picture of this puzzle online, made in wood, and it looked like it would be easy to design. That was the case.
This puzzle can be a little taxing on one's sanity to get together, but once it's together, it's kind of satisfying. Printing is easy. It should require no support, and little infill. Print six copies of the included STL. As usual, I've included the (brief) Python notebook I used to design this.