Persist-o-meter
Practice makes perfect. But real life gets in the way of practice. To solve the problem of pesky reality intruding onto his valuable ukulele playing time, Yurko Tymchuk has developed a progress tracker using 3D printing and magnets to record his daily goals. It looks a lot like a calendar, and every time you fulfil your goal for that day, you add a magnetised cross to the board indicating success. The text describing the goals is printed on detachable labels, so if you were to get bored with the ukulele and want to learn the piano instead, you’d just print a new label.
This is a 3D-printed model, but with some special instructions: first, it uses 0.2 mm layer heights, to get the best fit with the magnets he’s used. Second, in order to insert the magnets and to change colours, he had to pause and restart the print a few times.