[Kevin Kolodziej]

Team 1675 has built a telescoping lift twice: 2005 and 2008. Both years we used a pair of three nesting aluminum tubes (two stage lift). We did it a little bit different from a traditional telescope though where we had the largest diameter tube on the outside. The smallest diameter tube was our rigid tube welded to the frame. I believe we used 2", 2.5" and 3" tubes, all 3/16" wall (the first year we ordered the wrong thickness and actually had to lathe four of the tubes!!). Depending on your use, 1/8" or maybe even .090" would be sufficient. The first year we simply lubed the tubes and didn't have too many friction problems. The second time we used 1/8" delrin strips mounted to the outside of the inner two pipes 120 degree intervals. The sliding was extremely smooth and our lift was actually angled about 15 degrees.

Both systems were cascading. The first year we used a kit gearbox (essentially today's AM Toughbox) and CIM to drive a 3" drum. We used 1/4" sailing rope (very strong, very light, and quite colorful!) and machined pockets into the tube for the cables to run between stages. We also use Harkin Micro Pulleys. For 2008 we switched to spectra cable and tried to make our own pulleys but eventually installed the Harkin pulleys. This one used a 2" drum and used a dual FP winch. We only used our lift in competition once (at IRI) due to mechanism problems (not lift problems).

You can see a picture of our lift from 08 here. The brown stage is the outer stage and rides up on the gold stage. The gold stage also would raise up over a black stage (not visible) and have a total lift height of about 8'. The black stripes are the delrin slides. The wood was there for stability since we weren't using the lift (the gripper arm would keep stability normally).

Good luck to you!