I have a 100 pound platform that shall rest at a height of 6 feet. The
user will pull it down to about 3 feet and climb aboard. When the user
gets off, the platform should slowly raise to its original height of 6
feet. I plan to accomplish this using a pneumatic cylinder or two,
where one side is the platform and the other is a counterweight of
about the same weight as the platform. Will pneumatics be good for
this or perhaps a pulley system would be better? It shouldn't be too
hard to pull the platform down for a 150 pound person, and the platform
should not shoot up, potentially doing damage to the project, or anyone
nearby.

Ideas?

Jake