Inspired by /u/KrimzonK
https://www.reddit.com/gallery/1bfa49x

Can be printed in PLA, PETG preferred.

I highly recommend printing out the gear_game_2x2_25mm_pitch_test_card.stl to check the fit of the gears before committing to printing out all 36 gears and the larger game board. Gears and board are generated by file gear_game.scad and can be modified to fit your printer tolerance/scale.

Print the following:
1x game board
4x Player tokens in different colors, player_cart_simple for single color, player_cart for multicolor print
36x gears
4x 1pt Gems
5x 2pt Gems
5x 3pt Gems
5x 4pt Gems
5x 5pt Gems
4x 6pt Gems

Rules: (credit /u/KrimzonK)
https://old.reddit.com/r/boardgames/comments/1bfa49x/ive_always_wanted_a_game_that_use_gear_in/kv849qp/
Setup
Put Diamonds on the outside included corners with the number side facing up.
Each player one by one chooses which of the middle 4 squares you want to start from. Then the last player chooses which of the surrounding diamond to start filling the board from.
Fill the board with diamonds equal to the number of players. The number on the diamond indicates how many spaces inward from the edge the diamond will appear.
If a diamond spawn on a cog already occupied by one or more cart - neither player receive the diamond instead the next cart to arrive that that cog receives the diamond.
It is possible to have multiple diamonds on the same cog.
Any time a diamond has been collected please immediately spawn the next-in-line diamond onto the board.

Each round you may do any, none, or all of the following in this order.
1) rotate the cog 45° any number of times you like.
2) flip, orient and place one of the empty cog to its track side. You may not flip a cog that is occupied by a cart.
3) move your cart along a path collecting any diamonds along the way until you encounters an unflipped cog or fallen off the board.
If you encounters an unflipped cog - stop there. You may stopped in the same place as another cart.
If you fall off the board, on your next turn you must enter the board from the track where you've fallen off.

End of Game
Once all diamonds has been collected the player with the most diamonds win. If theres a tie - the player who went later in the turn order wins.