Algodoo

STICK-SLIP

I don't think this is caused by stick-slip because there is no difference between static friction and sliding friction in Algodoo. You will have to dig deeper to get the answer.

Are we talking about real world physics or Algodoo physics? If Algodoo physics, then I don't know enough about it to answer your question.

Real world physics.

When I was a kid, I had a table-top football game that made the players move around the field via a vibrating playfield. Here is a modern-day version of it: Vibrating Football Game

EDIT - Okay, I'll take a stab at it. I'm only going by my own gut feeling of how this type of feeder works. I believe it depends a lot on the shape, size, and weight of the item being conveyed. At a critical oscillatory frequency, amplitude, and waveshape the item gets "kicked" by the feeder, causing it to actually lift off the conveyer for a short distance and time period. The shape of the item determines which direction it will move, and how far. So, during vibration, the item rides along the peaks of the vibratory wave as it continuously gets bumped in one direction or the other. In other words, it rides along the standing wave. Other factors that may determine the direction and speed are static and dynamic friction coefficients, the item's inertia, and possibly other tertiary factors such as air flow, humidity, grease or dirt on the conveyor, etc.

I did not look this up. It's just an educated guess at the physics of how this works.

Looks like you are covering all of the bases. One particular word from your answer above would be a sufficient answer.

Strange... It doesn't work at 1200 Hz, which is very similar to real world physics! Maybe it is because the vibrations are tuned to work at 100 Hz with small inaccuracies. I wanted to play it in slow motion and that is how I discovered this.

According to my original research in Algodoo, the object actually 'sinks' into the conveyor! Only in Algodoo/Phun/simulators, because of low frequency. I once made a scene like this with 2 planes to vibrate the conveyor by being closer than the conveyor length, and it was very untidy so when I opened it the effect did not work.

heh