The afterthought bridge manipulator

[Sean Raia]

Originally Posted by BrendanB

We are using the gearmotor to lower our ball pickup/bridge manipulator with a 2 to 1 ratio and we sometimes need to get the bridge rocking to get it down. I'd recommend a 3 to 1 ratio and you'll get that sucker down no problem.

A simple solution I saw at GSR was 1519's. It is a simple triangle driven by a window motor that comes down and they just drive into the bridge and it comes down. Can easily be down with a limited weight budget! You can see it on the side of there robot here!

This design interests me, I wish I could get a better pic of that manipulator. I'l go hunting...

@Akash, You mentioned using a van door motor. Does that have enough torque to push the bridge down on its own, or is it better off being used for a wedge?

[Ken Streeter]

Originally Posted by Sean Raia

This design interests me, I wish I could get a better pic of that manipulator. I'll go hunting...

Below is a somewhat better photo showing the 1519 bridge manipulator on the robot at the Granite State Regional. One of the keys to the design is that the motor alone does not hold the arm in the lowered position -- in addition to the motor, there is a servo-actuated latch which retains the arm in the lowered position so that the motor housing does not bear the load of the bridge when the robot drives into the bridge to press it down.

[Phyrxes]

Depending on your design and use of "appendages" you could also use a "passive" latch using that is manually released after the match. But that would mean you are driving around with it permanently deployed if you have to manipulate a bridge early in a match.

At Chesapeake I noticed a good number of teams redesigning their bridge manipulators to either generate more force to be able to push the competition bridge down or to prevent the reaction force from damaging the deployment method.