Bridge device failure fix

[Brandon_L]

Many teams are finding out as they compete in their first event that their bridge manipulators are not strong enough to lower the competition bridges. We fell to this same fate, and spent our spare time at the event redesigning it. It was a simple enough fix that you could make a quick swap if you need it. I thought I'd share it on here, maybe someone else could get some use off of it. Excuse the paint drawing.



The red blob would be your bumper, COR is your center of rotation from the motor that is powering your device, and I drew in a badly drawn basic frame & front wheel. Note none if this is to scale. For best results, your COR should be around 12.5 to 13 inches off the ground. If its not, don't panic, you can modify the shape of the arm so that when the end is at its horizontal position it is ~12" off the ground.

There are three basic parts, labeled A B and C. Part A will extend from your center of rotation out of your frame horizontally to its max of 14" out of your frame. From that point, cut another piece (labeled B) so that the length allows it to go from the end of A to just in front of your frame below the bumper. Then simply make a final part (C) that holds B in place at the proper angle (which should be somewhere around 20 degrees, most likely, from part A ).

You just drop this arm down and drive into the bridge, and the edge of the bridge will follow the angle of part B and slide right into your wheel, and from there you just drive up. Its extremely smooth and reliable. Let me know if this helps anyone, just thought I'd post it up here. Remember to file and round any sharp edges!

EDIT: Works best with a window motor (worm gear) or van door (high torque, wont backdrive). I have no idea how it will react with other motors, you may need to lock it down somehow once its dropped.