Asking for trade secrets are we?
We tried using pneumatics, but couldnt nearly get enough height out of them (they couldn't release the air that was used to retract them fast enough). We tried precharging them and cutting a rope to release them, which helped, but it still wasnt nearly enough. I think our single best test with pure pneumatics yeilded maybe 4 feet vertically. This model uses extension springs.
We havent nearly planned ahead well enough to get a flagpole on the robot. This is just a mostly plywood model we threw together to test the concept. The camera is a few feet away, but the rig is just sitting on the ground (no chassis, its still being machined).