A spinning life counter for counting from 0 to 99, e.g. for playing Magic the Gathering. I designed the life counter to be simple to assemble and without the need of bearings or glue. Furthermore the wheels snap to the single numbers for a better usability (and because it's cool ;) )I've printed the life counters with no special settings and it worked well. You have to print the Inner and outer once and wheel twice (I know it's obvious, just to make sure). If the cylinders vanishes, when the model is sliced, check the option "detect thin walls" (for Slic3r). The assembly is simple, just put the two wheels on the outer cylinder and stick the inner cylinder in, so that the two noses are aligned together. If the inner cylinder doesn't fit well, cause by print inaccuracies, I heatet the square very short in a flame, so it is a little more flexible in that moment. For the numbers I used varnish paint, because the life counter will be touched often and every other paint rubbed off especially with sweaty hands. To improve the snapping, I filed the surfaces of the outer cylinder to remove irregularities and elaborate the edges more. To improve the spinning, I rubbed the top of the wheels on a sandpaper to smooth the friction surface. There is also an untestet version with 0.6mm walls for small nozzles. If someone prints it, I would be happy for a short message with the quality of the result. :)