[DonRotolo]

Google "crank up tower" and look at the mechanisms used for antenna towers that use mautiple sections to go from 20 feet to 120. The same basic idea works for robots.

2 years ago we used a simple elevating tower, a 24" stroke 3/4" dia pneumatic piston provided the lifting force, we telescoped 1 x 2 rectangular tubing inside 1.5 x 2.5, using HDPE wafers to keep the inner tube centered.

Don