I use this Coin Operator in my Emulation Gaming setups to select the games. But it's also a great fidget toy since the spring mechanism is quite satisfying. 

The front and the bolt need some support. Otherwise easy to print. The bolt funnels the coins to prevent stuck coins. Make sure to turn the wider part of the slit to the top.

Additional Parts:

• PN532 NFC Reader

• Spring 50mm x 11mm x 0.6mm

• NFC Coins 25mm

• 6 x M3x6

• 2 x M4x15

• 2 x M4 Nut

• 4 x M4 Washer