Captive Nut Fidget

This fidget is modeled after a classic machinist's puzzle, in which a nut is captured on a metal thread with caps at both ends. Unlike in a metal captive nut, however, this fidget's thread is a single piece.

This fidget is printed as two separate files. First, print the nut. Then, when slicing the thread, insert a pause in the gcode. When your printer pauses, thread the nut on and resume the print. To make sure the thread comes out cleanly, I recommend using a separate object as a prime tower. See the slicer screenshot for an example configuration.

To ensure the smoothest motion, you should break in the threads after printing is complete. First, thread the nut all the way to the bottom of the thread. Then, while applying upward pressure, thread the nut all the way to the top of the thread. Once you reach the top, apply downward pressure and thread the nut back to the bottom. This will grind the thread faces together and smooth them out slightly. Finally, wipe the threads off with your fingers. The oils from your skin will provide all the necessary lubrication for smooth motion.

This model is designed for printing with 0.2 mm layers, but any layer height should work. Feel free to mix and match the nut and thread colors, or even the materials!