2 CIM Motor Winch

[nakzz]

So my team has been trying to build a low-bar robot which can scale and we were thinking of having a winch mechanism to lift the robot up we grab the bar with a "elevator" mechanism delivers the hook.We have all the part pretty much designed and built, but we are having trouble with the winch.

We were using 2 CIM ball shifter gearbox from vex pro with 60 24 ratio. But the winch seems to fail when lifts the prototype robot (aprox. 50lbs). The motor stop and the robot hangs on the bar about 20 inches high from the ground. But the actual robot would be at least 100 lbs.

So is there any suggestions we can get? Maybe try changing the gear ratio? Different winch mechanism?