Fully Printable OTF Fidget Knife Toy - No Springs or Bands

This fully printable OTF (out-the-front) fidget knife toy delivers satisfying tactile feedback without requiring any purchased hardware. Unlike traditional designs, every component prints in one go—no springs, rubber bands, or assembly frustration.

The integrated coil mechanism is the heart of this design, providing the spring action that makes the blade deploy and retract smoothly. Coil direction significantly impacts performance, so you can experiment to find your preferred feel. Clean deburring of the 90-degree angles, especially where the spring lock catches the blade, ensures smooth operation right out of the printer.

This gadget makes an excellent desk fidget toy for anyone who enjoys tactile, mechanical objects. The OTF mechanism offers a satisfying click and motion that's ideal for keeping hands busy during calls or brainstorming sessions.