braking assembly 10 also includes a braking ring 40 having a flange 42 and a center cylinder 44 in this non limiting embodiment the braking ring 40 and the mounting ring 24 have about the same diameter the cylinder 44 includes a cylindrical opening 46 having a threaded portion that theadily engages the outer threads of the cylinder 28 so that the braking ring 40 can rotate on the mounting ring 24 a plurality of pins 50 are threaded through openings 52 in the flange 42 so that a tip 54 of each pin 50 extends out a back of the flange 42 a calibrated distance when the braking ring 40 is threaded to the mounting ring 24 the tips 54 of the pin 50 will contact an outer surface of the flange 26 for reasons that will become apparent from the discussion below the pins 50 are made of a softer metal than the mounting ring 24 in one embodiment the pins 50 are made of brass and the mounting ring 24 as well as most of the components of the braking assembly 10 are made of steel opposing brake stops 58 and 60 are mounted within the cylinder 44 by bolts 62 also for reasons that will become apparent from the discussion below the braking assembly 10.