Elevator/pulley help!!

I am a part of a rookie team and need help with a design for an elevator/pulley that can lift about 60-70 lbs?

Our team has thought about something like this:

I would like to know whether this design is realistic and where I can improve? I would also appreciate any recommendation on what to use for the motor without burning it, as well as, the material for the cable.

Thank You,
Team 4939, AllSpark9

Adam Heard has some videos about Elevator Design among other things in this Video Playlist

This video goes through a lot of the math involved.

Also - be on the lookout for the Robot in 3 Days Videos.
Several of the teams have already demonstrated some elevator designs that could start you on the right path.

I hope that helps.

thank you for that help…I really appreciate it.