[Ianworld]

Last year my team used a winch to lift our robot off the ground. We had a latching servo mechanism like a coupel teams have mentioned above. Just add a gear or sprocket to the pulley you want to lock. Then add a spring loaded servo with a piece of metal attached to the end of it that can jam up the sprocket or gear you placed on the shaft. Very simple. We jury rigged one up that was competition usable in an afternoon.

Now all that being said, i don't think teams will need a ratchet like they did last year. Think about the requirements for last years extenders. They had to be able to hold 130 pounds of force and they had to hold that once power was cut. Specifically the second reason was why teams needed a ratchet. This year you're probably lifting about 12 to 30 pounds depending on how heavy your manipulator is and how many tetras you're carrying. At most of the stock geardowns the motors will able to generate that torque without drawing much power and thus generating little amounts of heat. Its defenitly within the, "It'll surivive a 2 minute match and a victory lap" zone. That doesn't mean you shouldn't use a ratchet, just that its not necessary.

Finally if you don't have a ratchet what you do need to do is put your victors in brake mode. They have two modes, brake and coast. If you have them in coast mode they will just let whatever they are connected to backdrive. If they are in brake mode they will counter and backwards motion automatically(motors backdriven act as generators, so the current they generate acts a signal for the victor and it just sends the power back.) This will give the arm or winch mechanism the ratchet feel without a ratchet. This is how you generate heat in motors though.