pic: What is this?

[JamesCH95]

Originally Posted by Mr_I

YES! We discovered that #35 chain fits almost perfectly between adjacent pieces of 8020. Add to that the fact that the steel-to-aluminum friction is very low, and you've got a very good thing.
We mounted two verticle pieces of 8020 to the drive train frame, and ran the chain down the slot to a "elevator car" that rides on two pieces of 8020 about 12" long. (There's about 1/16" gap between the car and the rails, so there's little side-to-side drag. ) The car is attached to the chain at the top and bottom, and the chain loops out the bottom via sprockets back to the top. Add a Barbie to drive the sprocket, and we've got a low friction high strength elevator!

Your saving grace here is that the aluminum used for in 8020 is anodized. The anodized layer is very hard and wear resistant. Without this layer the aluminum would quickly gall and cause an immense amount of friction. I would definitely keep those slots greased or oiled in case the anodized layer starts to scrape off!