Team 2512 has a three tote stack, 2 bin auto as well, that was quite successful at Northern Lights, although it seemed to be less so Saturday afternoon.
It had a simple drive straight to gather totes approach. Bins were 'fished' up just in time with lines attached to very small aluminum hooks that were positioned on the far side of the first two bins, just under the bin lip. The hooks were held there by lightweight 'stanchions' made of styrofoam bases and vertical pool noodles.
One fishing line originated high on the left side of the bot, the other high on the right.
Auto reeled the RCs in 'just in time' and they dangled at the sides of the bot until the beginning of teleop, when the fishing line was let out to drop the bins and then reeled back to pull up the stanchions without bins.
Not sure why they didn't pull in the third bin as well.. maybe they figured a partner would be able to handle it in most cases (which wasn't the case-- other bots typically disabled their auto when playing with them.)
Sorry, no video link... I'm sure there is one somewhere. And this video at 1:00 is NOT it:
https://www.youtube.com/watch?v=85QW3h27lBQ