A moderator on my favorite puzzle-building forum called attention to a YouTube video entitled Magic Nuts and Screw Threads in which two nuts are shown unscrewing in opposite directions on the same threaded rod.
I don't have any inside information about the trick nut in the video, but I conjectured I could build a nut that would behave like that. The threas on my first test model turn a bit tightly, but it works!
I will record a better demo video later. It could use a little refinement, and the screw threads need to be a lot longer for a better demonstration. But it's sure gratifying when a new idea passes the proof-of-concept test on the first try!
Holy crap man! I am racking my brain trying to figure out the secret to this!!! Would you post a stl file?
ReplyDeleteI will probably post the STL files after I've explored a few variations and picked the best design. Bear in mind my bolt has unconventional threads, although they look fairly ordinary. Frankly, I'm afraid the actual solution might be disappointingly prosaic!
ReplyDeleteI promise there weren't any sneaky tricks, but this particular video has flaws: the bolt and nuts go out-of-view several times. But the last section honestly shows how both nuts behave on the same bolt at the same time.
I will post more pictures soon!
Scott:
ReplyDeleteVery cool that you were able to build it. I don't know how the original works, but you might be right about "continuous" suggesting "conventional" but not actually meaning "just like a real bolt." Those deceptive, weaselly words are everywhere...
-Bob, from Deceptology
I think I have it figured out now. I was hoping for some kind of magic nut that could spin backwards on any bolt. This is more of a magic trick than an engineering feat. Still very cool though.
ReplyDelete