[George C]

Looks a whole lot like what we came up with 6-7 weeks ago. We made ours higher (14") off the floor in case the bridge isn't quite level, used a dogleg to get the Centre of Rotation (about 4" off the floor) lower to keep weight low and put adhesive-backed UHMW on the underside of it. We also left a gap in the bumper so it is much closer to the frame. We found that the weight of the robot with a 14" moment arm stripped the gears in the window motor in our first version so we added a pneumatic latch which engages when it's down. It also helps us get over the bump. When it's up, we can use it to tilt the bridge away from us. It doesn't slow us down much so far.