Elevator Construction

[Orion.DeYoe]

I have been CADing and researching a variety of types of elevators used in frc recently. However I'm having trouble finding the kind of detail that I want from the successful designs.
Primarily I want to know the nature of the rollers/slides used in the elevator as well as the material used for the frame. I also want to know how they're rigged (continuous vs. cascading) and how they are driven (winch, belt, roller chain, pneumatic, etc.).
254 had a great elevator in 2011 however their roller block construction seems to be really involved and I can't find any good pictures of precisely how they're designed. I want to know if there is a simpler way to do it than with rollers. I've heard that using sliding blocks basically always binds and doesn't work at all, however are there any alternatives?
Please note that I completely understand the overall concept of an elevator (I don't need you explain to me what they are). I just need some clarification on the exact methods of constructing them.