The afterthought bridge manipulator

[Sb28000]

With the help of 2614 (M.A.R.S. - Thanks again, and congrats on the Regional win!), we built a bridge lowerer on Friday in Pittsburgh - we mounted a van door motor to a length of aluminum angle, and screwed that into a wooden upright already on our robot. We then sandwiched a bar of 80-20 with a 6" KOP wheel on the end of it on one side of the flat part of the shaft, with another piece of aluminum angle on the other side of the motor output shaft. Although functional, beware of the extreme torque and force that pushing down the bridge can cause, and the damage it can do to your 'bot. During a qualification match, we found that our arm did not have enough force to push down the bridge. Having tested it just minutes before that match, we were puzzled until we saw that a nut that had been sitting flush on the 80-20 bar was now pushed into the bar, with the top surface of the nut even with the surface of the bar. One of two bolts holding the whole thing together had now shifted and was not holding tension against the motor shaft. We swapped it out Saturday morning for steel on the surfaces touching the output shaft.