A spinning nut puzzle

[planetrob555]

The vibration coming to the nut is of the right frequency to cause it to move more in one direction that the other, causing it to spin off. If the frequency of the vibration where to be changed slightly, the nut would either just go back and forth, or not spin at all.

That's my uneducated guess.

[planetrob555]

@planetrob555 Also, I would guess that a lubricant acts to dampen the vibration that's transferred to the nut. Or the lubricant somehow changes the frequency of the vibration, causing it to not spin due to the change. Again, just a guess I pulled out of my...well you get it.

[planetrob555]

@planetrob555 One last guess is that the lubricant adds "mass" or weight to the nut, and therefore the frequency of the vibration needed to spin the nut one direction has changed quite a bit, enough to stop the spinning.

[jelewis2]

It spins because the pattern of application of frictional force on the nut is circular, and lubrication slows the spinning down because it reduces the friction.