This is a 4-digit mechanical number counter with push button mechanism. Fun fidget toy or use it for actual counting. Only non-printed part needed is a 9x35mm compression spring. This version doesn't have a separate reset function, but I've found the easiest way to reset is by unscrewing the cap 1 rotation, slide number gears towards the cap by finger and turn them. The counter can be turned backwards by pressing the button slightly and turning the first wheel by hand. Have fun printing!

Tips for smooth function:

-Make sure support faces are smooth, especially on mid number wheel and carry gears

-Minor sanding of the gears may be needed depending on the quality of print

-Add lubricant on the gears if needed

-Threads can be stiff at the beginning. Carefully screw and unscrew the cap a couple of times to make screwing it easy.

-Keep using it, after a while it works more smoothly

Assembly video link (3 digit version):