Single Thumbwheel Counter (00 to 99) using a Geneva Drive.

Support:

The case_bottom needs support.  Nothing else requires support.  Carefully remove the support in the case bottom before assembly.  Printing the Geneva gear at 0.12 layer height is recommended for smoother operation as z-seams negatively impact smoothness of the mechanism.  The rest can be printed at 0.12 or 0.20 layer height.

Assembly:

Put the middle moon gear in the case bottom gear side down, then point the peg on the moon gear at 45 degree angle away from the thumbwheel.  Next put in the thumb_gear with the 0 at the innermost number, then add the Geneva wheel with zero at the center.  If the post on the middle gear is aligned, it should slide together easily without forcing.  Check the alignment of the numbers to make sure the tens place rolls over as expected and then and press on the top case to hold it all together via friction fit.

If the movement sticks, smooth out Z-seams.

This is a remix of:

https://www.thingiverse.com/thing:4097275

which was a remix of:

https://www.thingiverse.com/thing:1290507

Enjoy!

I remixed this design to loosen tolerances for a smoother operation, make the numbers easier to print and read (larger), make it stronger where I could and also require less fiddling to assemble off the print bed.  There are only 5 parts and it took me about two hours to print.