This is a remix of "Fully Printable Tank Tread Assembly" by laird. I only made the following changes:

1. Made center support as wide as handle for a more reliable print (the post got knocked over on my first try).
2. Filled holes in inner most gears.
3. Scaled to 110mm length.

The result is a fun fidget toy that isn't too big and doesn't take too long to print. I made two, one with Green Hatchbox PETG and one with the grey filament that comes with the prusa i3. The PETG one has withstood a week or so of play. The PLA one can't seem to keep the belt on and I broke the belt within the first few rotations. I would definitely recommend printing in PETG.

For the PLA print I had to turn off "wipe while retracting" or the chain links would be wiped off the build plate. I would recommend turning this off for PETG as well, but it is not required.

The belt is a little stiff when first printed. You may want to slip it off, run it through your fingers and put it back on. Make sure the V is in the correct direction.

Edit: I added a belt only and no belt files based on a request. They not needed for the toy, but they can be used for spare parts, multiple colors or testing your printer. I tested the belt only file in purple and put it on my previously printed green gears.

I'm also adding the .f3d file exported by fusion. I don't expect it to be very useful. It is the size of the original thing I remixed from because I scaled the .stl in prusaslicer.