We used a disc brake in 2015 like many teams to hold the position of our elevator without having to stall the RS775 motors that powered it.
We purchased
this kit off Amazon and mounted 1/2" hex versahubs to the rotors. We then used a small pneumatic actuator to pull on the brake cable whenever power wasn't being applied to the elevator. It was incredibly easy to set up and install from a mechanical perspective and we never smoked an elevator motor during our matches.