Who Has a Bridge-Balancing Mechanism?

[Nathan Streeter]

When I say a "Bridge-Balancing Mechanism," I mean one that could be used by a robot on a bridge to help an alliance balance. Essentially, I'm thinking of mechanisms similar to 33's "Stinger," 67's Multi-Function Arm, or 148's within-the-frame-perimeter leg.

These bridge-balancing mechanisms help teams balance the bridge, particularly with the difficult triple balances. I was hoping this thread could compile a list of all the teams that have one.... I'll start it off with the ones that I've seen videos of or heard of:

- 33's "Stinger," a four-bar linkage appendage
- 67's innovative and highly-versatile arm
- 148's "Peg Leg," which linearly pushes down within the frame perimeter
- 469's "Peg Leg," which I've only heard about
- 1986's "Teeter-Totter Talons"
...


Also relevant are special features designed to make balancing (particularly triples) easier by methods other than actuating the bridge into a balanced position. How successful have these each been?

- 179's innovative under-the-bridge hanger (Has this been used in competition? Was it ruled illegal with 118's side-hanger?)
- 701's Roof Platform, which allows a team to park on top of their robot (from video, this seemed difficult to execute)
- 1501's Ramp/Lap Platform, enabling a team to drive onto their robot, creating a bit more space on the bridge (has completed a triple)
- 2054's similar Ramp/Lap Platform (hasn't completed a triple, I believe)
...

[legogeek24]

3456 had a mechanism similar to 148's at Utah, but never actually utilized it. We are hoping to revamp it for a Championship unveil!

[BigJ]

1675 also had a bridge arm. Didn't have a special name, but I always called them mantis arms. From what I know it was used successfully in a couple matches, but never to triple balance.

[Jared Russell]

A 28" (or less) long robot seems to be a pretty good bridge balancing mechanism

(But yes, with stingers being all the rage this season, we couldn't resist)

[Nick Lawrence]

I'm pretty sure several teams with motor-driven drop-down intakes/bridge manipulators (like 610 for example,) can use them to aid in the balancing of a bridge.

-Nick

[thefro526]

Originally Posted by Nathan Streeter

- 33's "Stinger," a four-bar linkage appendage
- 67's innovative and highly-versatile arm
- 148's "Peg Leg," which linearly pushes down within the frame perimeter
- 469's "Peg Leg," which I've only heard about
- 1986's "Teeter-Totter Talons"

469's Stinger is similar to 33's in the way it works. Basically a simple 4 bar linkage that leaves the frame perimeter and pushes down. (At least from what I could tell in the webcast.)

Originally Posted by Jared341

(But yes, with stingers being all the rage this season, we couldn't resist)

In your case, wouldn't 'Root' be a more appropriate term?

[Madison]

1425 has a mechanism that operates similarly to that of 148.

We've lost to both of them.

[AlecMataloni]

I saw a team at Midwest that had a grappling hook on their bridge manipulator that was used to pull their alliance partner up the bridge and to minimize movement adjustments.

Can't seem to remember the team number, though .

111th post, by the way!

[Brandon Holley]

Team 3958, led by the famous Joe Johnson has one heck of a creative robot this year designed for triple balancing efforts.

They have a drop down "slide drive" type system so their robot can traverse either in the long direction or the wide direction. The coolest part about this mechanism is the fact that the power is transmitted 90deg throughout the drop down system utilizing nothing but friction. The pneumatic wheels in each system rub against each other to provide drive in either axis.

In addition to this, they have 4 independent "stilts" that all lie within the frame perimeter. They use these to drop down and lift/stabilize the bridge. They were able to successfully complete a triple balance in Boston this past weekend. To balance successfully, they only need to get their front wheels onto the bridge, and then drive their stilts down. When the bridge gets close to level, they can drive forward a bit, wait for the bridge to settle and retract the stilts.

On the practice field I saw them complete a triple balance in less than 15 seconds, which was quite impressive.

OH yeah, they also had an arm/intake/hopper/dumper mechanism that deposited 2 hybrid shots into the side goals extremely consistently, and was good for about 3 or 4 more in teleop. One heck of a robot for a rookie team.

-Brando

[MCahoon]

Bear Metal FRC 2046 uses two cylinders installed in our "multi-tool" to push the bridge up to balance. We've practiced with it a number of times on the practice ramps with partners, but haven't yet used it in competition.

http://tahomarobotics.org/wp-content...e-2012-060.jpg

[Nick Lawrence]

Originally Posted by Brandon Holley

Team 3958, led by the famous Joe Johnson has one heck of a creative robot this year designed for triple balancing efforts.

They have a drop down "slide drive" type system so their robot can traverse either in the long direction or the wide direction. The coolest part about this mechanism is the fact that the power is transmitted 90deg throughout the drop down system utilizing nothing but friction. The pneumatic wheels in each system rub against each other to provide drive in either axis.

In addition to this, they have 4 independent "stilts" that all lie within the frame perimeter. They use these to drop down and lift/stabilize the bridge. They were able to successfully complete a triple balance in Boston this past weekend. To balance successfully, they only need to get their front wheels onto the bridge, and then drive their stilts down. When the bridge gets close to level, they can drive forward a bit, wait for the bridge to settle and retract the stilts.

On the practice field I saw them complete a triple balance in less than 15 seconds, which was quite impressive.

OH yeah, they also had an arm/intake/hopper/dumper mechanism that deposited 2 hybrid shots into the side goals extremely consistently, and was good for about 3 or 4 more in teleop. One heck of a robot for a rookie team.

-Brando

I've been waiting patiently for months to see this robot. Are there any photos of it?

-Nick

[Jaxom]

Originally Posted by Nathan Streeter

Also relevant are special features designed to make balancing (particularly triples) easier by methods other than actuating the bridge into a balanced position. How successful have these each been?

931 has a lead screw going the entire length of the robot, with weights (including the battery) that can be moved forward our backwards to change their CG. The position of the weight also factored in to their ability to go over the bump. Whether or not this would be helpful for a triple I don't know; we were with them in two tournaments, neither of which had a triple balance.

[Brandon Holley]

Originally Posted by Nick Lawrence

I've been waiting patiently for months to see this robot. Are there any photos of it?

-Nick

We have some in our scouting database, but that is currently in the lab, where I am not.

[Jetweb]

Originally Posted by Nathan Streeter

- 179's innovative under-the-bridge hanger (Has this been used in competition? Was it ruled illegal with 118's side-hanger?)

We were approached by the head ref at our first event and told that our design was deemed legal by the GDC and we were not penalized during our few attempts at hanging.

We ran into an unexpected problem at the Orlando regional with bridge deflection not allowing us to hang during a competition match. While there we did come up with a fix that unfortunately did not get to be attempted in competition. We do believe we have the bugs worked out and will be hanging at the south florida regional in a few days.

[nikeairmancurry]

We had something very similar to the 469 peg leg. It was a rod with a wheel that was pull down by a fisher price motor. It was very helpful on performing quick two robot balances where the rock in the bridge was at a minimum. It also was pretty good at assisting with the triple balance on the practice field before elims, but we never got to use it. I'll post a picture when I can.