[SML] Sorting screws automatically?

[Joe D]

Sorting all those wood screws from tear-down is universally loathed.  I am sure there are some methods in industry that we can apply.  

I can imagine how a v-shaped trough that is being vibrated would tend to align the screws along the V-point. Though, the threads my tend to keep them bunched together, unless the vibration is at least the diameter of the screw in amplitude.

If there were simply a slot at the point of the V, then smaller screws would drop through, but larger ones would get stuck at that point.  A rolling wheel just after the slot may propel the longer screws further down the sort line, But, we are now starting to get more complex that I would prefer, and more expensive than the money saved by re-using the screws.

Aside from students doing it manually, any other thoughts on how to accomplish this?

-Joe