Better bearings or better balance?

Also, how long should this platform run? Till the end of December? Once in a designer show house I provided a control system to operate a TV pop-up that was custom built by a machinist. I was very leary of its construction and slapped a motion detector and a timer on the lift. If someone walked into the room, the TV would pop-up and stay up for a couple minutes before retracting. It would stay down for a couple more minutes, then pop-up if there was motion. After about 20 days the lift failed.