How does one fasten a rotating joint that does not self-tighten or self-loosen?
I'm trying to make a "slider crank" mechanism (for cheap) where all the movement is parallel to the ground. There are no huge forces at play, hoping to push a slider of a couple hundred grams ~15cm/6". Not my diagram, but essentially this:
There are plenty of photos online, but I'm unclear how to robustly make joints (looks like they're labeled B and C in the diagram above). I've tried something like this:
but with the continuous rotation the nut eventually loosens or tightens.
Accepting that any pieces of hardware-store materials can be modified to suit, what is a good way to fasten these joints?