Spring Fidget

This started as a portion of a 3d printed clock design I am working on, but the clock is incomplete, and I realized this was a pretty cool fidget in its own right. It uses a standard Bambu cardboard spool center as the housing. 

Twisting the crank counter-clockwise winds the spring. Release the crank for it to retract. Be careful not to crank clockwise as it will destroy the spring.

This is also a good model if you want to see how a spiral torsion spring works.

Assembly Instructions

1. Wind the spring by holding the center piece and pulling the end to compress the center. Rewind the spring around the smaller center.
2. Repeat step 1 as necessary to reduce the spring diameter.
3. Insert the spring into to the inner section of the outer spring housing.
4. Push the crank through the bottom hole; lock the center of the spring onto the crank.
5. Install the inner spring housing, making sure to align the notch in the wall with the hook on the spring.
6. Remove the RFID tags from a spare Bambu spool.
7. Insert the assembled spring housing onto the spool, again making sure that the notch on the assembly lines up with the notch on the spool.