Better Than NASA Ratchet

thingiverse

- Changelog: V1.2 - Opened up the clearance around the mechanism on the bottom layer to allow for some of my more melty filaments to be used. - Reduced the size of the square drive a hair since socket fit was very snug. Tweaked a bit to fix an asymmetry between loosening and tightening directions. - Beefed up the thickness of the selector shaft. - Added pinholes to selector shaft and ratchet arm shafts to strengthen them. - Added a 1/4" drive version. V1.1 - Based on the more radiused v1.0 design with pinhole. - After torture-testing a 4-pass wall print (which should have had a layer-adhesion failure in the square drive) one of the ratchet arms bent internally. I've beefed up the internal mechanism a lot. It will be way more stiff when ratcheting, but should take quite a bit more torque without failure. V1.0 - Initial prototype. - Three versions are uploaded, with and without the pinhole in the square drive, and also a more radiused version with the pinhole. Inspired by the infamous NASA space-ratchet, but designed from a blank canvas. The only part copied from the original part is the 3/8" square drive because I liked how theirs was tapered and it saved me the time of designing it. The NASA ratchet is cool, but the fit is sloppy. Even my bone stock Ender 3 Pro can print gaps a third that size reliably. Also, the ratchet mechanism is a cylinder, with 45-degree chamfers. This makes it quasi-spherical... sphere-like part in a sphere-like hole results in a large amount non-preferred-axis rotational play. Basically it was way too loose. Also the ratchet spring being permanently attached to the sidewall (rendering the tool useless if it let's go) is a failure point which could easily be eliminated. Lastly, the darn thing is non-reversible. I just felt like it wouldn't be that hard to do better, even for someone like me whose design skills are just so-so. So here is the better-than-NASA ratchet prototype. Its only my 3rd alpha-testing print (the first two have been split apart to examine what wasn't working as intended), and I was shocked when the darn thing functioned perfectly. Feedback is welcome, I had fun designing this and can totally make improvements to it. I plan on refining the radiussing and improving the hand-feel now that the internals are happy.