[Anyun]

Two years (Logomotion) ago our initial placement mechanism for the inflatable pieces used a linear slider (we scrapped it later in favor of a pneumatic arm). Anyways, we did it by using brackets and a pulley system. The brackets were used to make sure the channels didn't go to far up and fall, and the channels were just slid on to each other. The pulley would force the channels to slide along each other until they hit the bracket above them, then the next piece would start rising.

It wasn't very effective for us, and I doubt it will work well, but it's a starting point if you're desperate.