forklift system trouble!

[Hawiian Cadder]

http://www.alpinerobotics.com/images...bui.php?page=2

here is a pretty good image of what we did in 2007, it worked really well and we have basically duplicated the lift, our team has been refining the lift design there for 4 different challenges, 2 by 1 by 1/8 c channel is used for the rails, with bearings and washers on shoulder bolts to slide along it, all the stages are driven by one input, on that year it was a pair of r550's in a 48-1 reduction, this year it is a FP in a dewalt , (anti back-drive pins intact) be sure to allow a little flex because the extruded channel is not perfect.