This is my own version of, what I've come to realise, is a commonly known puzzle! I first saw it in this video: https://youtu.be/xp-PENvptu0
I was looking for a little experimental project to learn more about 3D printing and in particular about the clearances needed to make matching parts fit well together. In the end I found that adding a buffer of around 0.15mm on each side between parts works well. As it is, these parts straight off the printer do fit, but very tightly. After some working and cleaning they slide just great.
I've also seen other examples of the same puzzle on this site. This is not a remix, it is my own take but admittedly it is very similar.
I also experimented with spray painting the bottom half for contrast. It seems OK for now and I will see how well it holds up to being handled.
Another finish detail experiment that worked well was some inlaid text on the lid that I "flood filled" with some nail polish. I dripped it in using a toothpick and then once dried I just used a knife to scrape off bits that had overflowed onto the lid. I think it gives a very nice labelling effect.
For the magnet I used a 6x3 mm N52 Neodymium Disc: http://r.ebay.com/73SqQq
It is super glued into the recess printed for it in the lid. The press fit was almost tight enough but then the ball would pull it out, so super glue was necessary to make it stay put.
For the ball I used an 11mm ball that my kids had from magnet construction toys.
No supports or rafts needed for this model and I printed with 0.2mm layer height. Took about 10 hours to print both parts side by side.
UPDATE: 05/03/2018 I added files for v2.1 with slightly more clearance so the 2 parts fit together pretty much straight off the printer (thanks to feedback from Qrome).