Who Has a Bridge-Balancing Mechanism?
 

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)
...

Re: Who Has a Bridge-Balancing Mechanism?
 

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!

Re: Who Has a Bridge-Balancing Mechanism?
 

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.

Re: Who Has a Bridge-Balancing Mechanism?
 

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)

Re: Who Has a Bridge-Balancing Mechanism?
 

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

Re: Who Has a Bridge-Balancing Mechanism?
 

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.)


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

Re: Who Has a Bridge-Balancing Mechanism?
 

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

We've lost to both of them. :(

Re: Who Has a Bridge-Balancing Mechanism?
 

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! :D

Re: Who Has a Bridge-Balancing Mechanism?
 

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

Re: Who Has a Bridge-Balancing Mechanism?
 

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

Re: Who Has a Bridge-Balancing Mechanism?
 

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

-Nick

Re: Who Has a Bridge-Balancing Mechanism?
 

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.

Re: Who Has a Bridge-Balancing Mechanism?
 

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

Re: Who Has a Bridge-Balancing Mechanism?
 

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.

Re: Who Has a Bridge-Balancing Mechanism?
 

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.

Re: Who Has a Bridge-Balancing Mechanism?
 

2337 - Has a peg leg that was inspired by 148 and 33.

We successfully used it at Northville for the Coop Bridge as well as a Triple Balance.

Video of the Triple Balance:
http://www.youtube.com/watch?v=3p0aiLfUM1k
http://www.flickr.com/photos/danielernst/7018508605/

Picture:
http://www.flickr.com/photos/danielernst/7017927741/
http://www.flickr.com/photos/danielernst/6871821718/

Tribute:
http://www.chiefdelphi.com/forums/at...5&d=1332792423

-Clinton-

Re: Who Has a Bridge-Balancing Mechanism?
 

i dont know if this counts but team 2175 has a braking mechanism on our robot that allows us to hold our ground on the bridge. Its just two small cylinders that push into the wheels and lock our whole drive train in place

you can see one of them in picture 78 here (on the leftmost wheel)
http://robotics.mnmsa.org/media/photos/

and you can see them in action here
http://www.youtube.com/watch?v=jG9Di730AZk
~58 seconds in

Re: Who Has a Bridge-Balancing Mechanism?
 

256 has one - It's 27"x37"x40", weighs a little over 90 pounds, and just happens to score basketballs. :p

In all truth, our whole robot is our balancer; It has a few automatic balancing modes, a brake mode, which resets it to it's previous position in the event it's moved, and a few gyros to help it know it's position.

Surprisingly, robots can be great balancing mechanisms by themselves with a few sensors and some software.

Re: Who Has a Bridge-Balancing Mechanism?
 

3098 had one for eliminations, they changed their bridge lowering device for a four bar "stinger". 610's deserves more of a shout out as well, their bridge lowering device can point straight down to stop a bridge from swinging too far down.

Re: Who Has a Bridge-Balancing Mechanism?
 

Well...148 isn't the only Texas team with a bridge mechanism anymore...

Tune in to Lone Star and you'll see a few. Hard to say how many, but I know of a couple. ;)

And some of them work really well with long robots...

Re: Who Has a Bridge-Balancing Mechanism?
 

at Seattle i saw two teams with double "peg legs" I saw them both work in practice but never during the competition

2046(never had a need for it), 3662(removed for weight?)

both where original designs from what i saw.

Re: Who Has a Bridge-Balancing Mechanism?
 

3958 had one at the Boston Regional. It's really cool, but from what I could see, it took a while to use it to actually balance with it.

Re: Who Has a Bridge-Balancing Mechanism?
 

Team 1099, the DiscoTechs, designed their robot so that the shooter, ball picker upper, and the device that holds and brings up balls are all one piece, which allows for everything on the robot to be shifted, meaning we can shift our weight on the bridge easily

Re: Who Has a Bridge-Balancing Mechanism?
 

After Kansas City Team 967 decided to build a bridge balancing arm. We decided on a design inspired by HOT team. Although we could get a triple balance in about 20 seconds on the practice field at Wisconsin (Thanks to teams 706 and 2506), we were never able to attempt the triple during an actual match.

The arm also helps from tipping during single and double balances, and also from getting balls from hard to reach places.



Here is a practice triple balance in our shop with our practice robot, and 2011 robot.


And a closeup of the arm

Re: Who Has a Bridge-Balancing Mechanism?
 

In the vein of "other" mechanisms, team 1218 has a pneumatic brake that extends from the bottom of their robot to help them stay in place and consume less space on the bridge.

Re: Who Has a Bridge-Balancing Mechanism?
 

Without wanting to give away too much, 1218 will also be adding a few new features to aid in a 3 robot balance.

Re: Who Has a Bridge-Balancing Mechanism?
 

No stinger yet ( ;) ) but we do have the pneumatic brakes working so we can act as the other end of the robot congo line without falling off.

https://www.youtube.com/watch?v=9NDBSpexx5w

Re: Who Has a Bridge-Balancing Mechanism?
 

217 has what they refer to as a "Dingus". Although I did not get to see it inoperation during Chesapeake...

Re: Who Has a Bridge-Balancing Mechanism?
 

Team 3476 has an exemplary one! A wedge locks in place in the back of our robot with two steel levers. That way the driver can just drive onto the ramp, with the bridge lowering consecutively.
-CAD Video- to see the bridge control, go to 56 seconds.

Re: Who Has a Bridge-Balancing Mechanism?
 

Team 2180 has a braking system which is nothing more then a bicycle brake attached to a servo with some fishing wire.... Talk about simplistic bubble gum and paperclips solutions. It works very effectively and has made co-op balancing a breeze for us...
http://www.facebook.com/photo.php?fb...type=1&theater

Re: Who Has a Bridge-Balancing Mechanism?
 

Team 842 is close to finishing our amazingly complex brand new stinger. We are very tight on weight right now so we had to go extra simple on it. Did some initial testing today to see if it works and so far everything looks good. Will post video of full test tommorow:

http://www.youtube.com/watch?v=xEy59...73FAAAAAAAACAA

Enjoy.

Re: Who Has a Bridge-Balancing Mechanism?
 

We recently took the biggest piston that we could find, put a ball cap on the end and riveted it to the chassis of our robot. Works like a charm.

Sometimes dumb ideas just work really well :P

We can now balance the bridge with only two wheels on the bridge (not legally).

Re: Who Has a Bridge-Balancing Mechanism?
 

GTW -- 2056 just showed (successfully) a pneumatic balancer on coop bridge, don't recall seeing that before

strapped onto the side of their collector

Re: Who Has a Bridge-Balancing Mechanism?
 

Check out team 118 at the Northeast Regionals in Hartford, CT.

The G10/Bridge grappler is gone. Now they have a complete bridge package. Pretty impressive.

Re: Who Has a Bridge-Balancing Mechanism?
 

It also looks like 1114 has one on the back of their pretty machine..

Re: Who Has a Bridge-Balancing Mechanism?
 

Team 2054 has one, here is a video of a promo for Michigan State Competition
This is the Thread: http://www.chiefdelphi.com/forums/sh...highlight=2054
This is the video: http://www.youtube.com/watch?v=wjXBz...ature=youtu.be

We have a Big Arm that comes down outside the frame on a pnuematic cylinder, we have used it in double and triple balances. it worked quite well, we balanced every time we got a chance to at niles.

Re: Who Has a Bridge-Balancing Mechanism?
 

Does software count? We have that, a function that holds the drivetrain in its current position (a software break), and just plan old fancy driving. That's worked for us...

Re: Who Has a Bridge-Balancing Mechanism?
 

Does the software brake work once power is cut?

Re: Who Has a Bridge-Balancing Mechanism?
 

I can confirm this, we added the device on Thursday of GTRW. Special thanks to Teams 67, 148, 217 and 469 for inspiring us to go in this direction.

Re: Who Has a Bridge-Balancing Mechanism?
 

I don't know if it's been mentioned, but 179's bridge balancing mechanism, if you consider it one (since most of these so far have been legs or arms) is my favorite of the season, superb in every way.

It's here: http://www.youtube.com/watch?v=C_m64ATj3b4

Re: Who Has a Bridge-Balancing Mechanism?
 

I'm guessing there will be more new bridge mechanisms going on display by several teams at Queen City. Just a guess.

Re: Who Has a Bridge-Balancing Mechanism?
 

1023 added a simple one for Livonia as we had very little weight to work with, but did not use it during competition. We did successfully balance 3 several times on the practice field Saturday morning, but did not attempt it during a match. Thanks to 2137 and 2619 for testing it out with us!

Re: Who Has a Bridge-Balancing Mechanism?
 

180, SPAM, has a flipper they use to triple balance, lower the bridge, and traverse the barrier.

They didn't need to use it in Orlando or South Florida. They did, however, successfully use it on the SoFla practice field with 1592 and 3627 four or five times in a row before packing up to queue for elimination matches.

It can be seen at the 40 second mark of this video.

Re: Who Has a Bridge-Balancing Mechanism?
 

On the practice field before elims, we were able to balance 3 long base robots. 869 has their battery on a track, which allows them to shift weight. Buzz Team 175 has one heavy end, with a brake, to allow them to hang half their robot off the bridge.

We (team 126) have tossed around the idea of using our bridge manipulator as a "stinger", or designing something before going to STL.

Our 3 long base bots balancing in 30 seconds: http://youtu.be/_-BasVh4beo

Re: Who Has a Bridge-Balancing Mechanism?
 

We had something very similar to the 469 wooden leg. It was a rod with a wheel, pulled down by a motor from Fisher Price. It was very useful to quickly balance two robots, where the rock was reduced to a minimum in the platform. It was good enough to help the balance of the scope of practice for the Elim, but we never use. I'll post a picture as I can.

Re: Who Has a Bridge-Balancing Mechanism?
 

We had one at CT and used it quite a bit for the coop bridge as well as to triple balance in the eliminations. Can't wait to use it again at St. Louis with, weight permitting, a slight improvment.

Re: Who Has a Bridge-Balancing Mechanism?
 

Does it have to? I thought breaks would be used for fine tuning the balancing. Once your balanced your balanced, theres no need (or at least shouldn't be..) for a break to stay balanced. Just like with the stingers. One your balanced, their useless. But they help for a speedy balance

Re: Who Has a Bridge-Balancing Mechanism?
 

1918 has a servo actuated, spring loaded, kickstand that folds down from the bridge tipper, and then is powered as part of that assembly. We used it for our triple at Troy. The brigde balancer add-on weighs less than 1 lb.

Re: Who Has a Bridge-Balancing Mechanism?
 

2224 does... well kinda we just drop down and retract them to shift the robot's center of gravity

Re: Who Has a Bridge-Balancing Mechanism?
 

finals quick mod for easy triple balance 1" pvc on the center robot that flips down after the start of the match and the other two robots have 2" pvc on their bots they all connect and whala the first robot in the train tips the bridge and they balance no robots tip and no fancy engineering a cheap easy mod

Re: Who Has a Bridge-Balancing Mechanism?
 

1662, 973, 254, and 1323 from CVR had stingers. However only 1662 successfully used theirs in a triple balance. 1323 used their 4-bar stinger during a few qualification matches.

Re: Who Has a Bridge-Balancing Mechanism?
 

Team 179's mechanism has several prposes. when it hangs off the end it is pretty effective but it balances by such a little marging its hard to judge. Its also dangerous for partner robots as only very heavy robots or 2 othere robots can balance and they must balance very far off the other end. Their robots biggest use is lowering the bridge for others and being used as a ramp.
Its really cool to watch though, and always makes the end of a match more exciting:)

Re: Who Has a Bridge-Balancing Mechanism?
 

3847 got our jacks working on Saturday at Lone Star, never got a chance to use them though, but we should be good for St. Louis.

Re: Who Has a Bridge-Balancing Mechanism?
 

Yes it does. Because once the power is cut, everything shuts down, leaving the wheels to roll freely which may "unbalance" the bridge. This happened at the MSC with a triple.

Re: Who Has a Bridge-Balancing Mechanism?
 

While I won't go as far as saying that Miss Daisy's "stinger" is as effective a bridge balancing mechanism as 67's arm, the 341/25/1640 alliance was triple balancing just as quickly as any of 67's alliances.

Re: Who Has a Bridge-Balancing Mechanism?
 

862 added a pneumatic cylinder that we used to triple balance in the MSC Quarterfinals

Re: Who Has a Bridge-Balancing Mechanism?
 

Here is a video of our team in competition.
http://www.youtube.com/watch?v=Kjo4p...ure=plpp_video

Re: Who Has a Bridge-Balancing Mechanism?
 

There was a robot that used a long piston to balance on the bridge. on triple balances, the last robot seems like it is about to fall off the bridge when it is about to balance. What if you use a long piston that touches the ground while the robot is on the bridge? that will prevent the last robot from tipping over, if it extends the piston while the bridge is balancing. after being balanced, it can retract the piston.