Bridge Manipulator
 

I have seen three types of bridge manipulators triangles like 846's robot, i have seen just straight metal pushing down on the bridge like 233's robot, and i have seen wheels like our robot 1649's robot. I was wondering what type of bridge actuator you used if I missed it and which bridge manipulator worked the best. I know that all three types were able to get the bridge down but I want to hear your pros and cons for each bridge.

I like the triangle manipulators because you don't have to push down on the bridge you can just lower the manipulator and drive up and over.

Re: Bridge Manipulator
 

Sorry to ask, but aren't the "triangle" from 846 and the "straight" wedge from 233 just different implementations of the same thing? They are both passive manipulators, unless I have misunderstood the design of 233's system.

Either way, we had passive wedges with a triangular arm on each edge of the robot and a lexan strip between them. We also had locks on each arm so we could put all our weight behind the manipulators. Except for the rare time when the lock failed to engage correctly, we barely had to slow down to climb the bridge. We were very happy with their performance overall.

Re: Bridge Manipulator
 

Our bridge manipulator was a passive-wedge style with a gate lock to hold it down.

I have to say, our robot was full of inconsistent components, but the bridge manipulator worked better than we could have hoped.

- Sunny G.

Re: Bridge Manipulator
 

They are both passive bridge manipulators but they are different designs one was built directly just to push down on the bridge while the other one was built to push down the bridge as the robot approached it.

Re: Bridge Manipulator
 

My team had a "passive" manipulator that was essentially two thick sheet metal tusks put together, lowered by a single pneumatic piston (we changed it from the original picture). This let us drive straight into the bridge without stopping, saving us precious time, but we were also able to lower the piston when the Joebot was right in front of the bridge, so it could be used "actively."
You might notice that the top of the tusks is very close to the edge of the bridge. Every once in a while, we encountered an issue with the tusks driving under the bridge and pushing it up.

Re: Bridge Manipulator
 

So this would make it active, not passive, right?

Correct

Re: Bridge Manipulator
 

See this thread.

Re: Bridge Manipulator
 

Re: Bridge Manipulator
 

I believe we (2914) had a really unique system. Just drive into the bridge to tip it the other way, or drive back then forwards and it will swing right to us.

Re: Bridge Manipulator
 

3397 had a "hammer" (actually it was a pvc arm with an elbow joint) on our robot that was powered by a Fisher-Price motor with the standard KoP gearbox. It worked beautifully.

Re: Bridge Manipulator
 

Like someone mentioned, we were subtly different from the triangular wedge. Here is a short report that explains the design considerations

http://f.cl.ly/items/3l203Z2v272J1n3...her_Report.pdf

Re: Bridge Manipulator
 

Is the manipulator we're looking at supposed to be the "roll cage" like polycarb or the piece of aluminum somewhat under your shooter?

Re: Bridge Manipulator
 

Our wheelies were incredibly consistent with lowering the bridge... even in autonomous :D

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We used our cannon to get the bridge down. Worked every time!

I loved your wheelies they where really cool to watch on Einstein but I have a question for you. Did you guys build your robot knowing it would be able to do wheelies to push down the bridge or was that something you found out after building it? I was wondering this for a long time and my bet is on you found this out after building the robot.

Re: Bridge Manipulator
 

Team 610 used two arms that were driven by a bane bots 775 motor, which allowed us to vary the position of our manipulator. We would push the bridge down with our arms, and then use them as a wedge to drive up on the bridge.

One major pro of our manipulator was that we were able to use it to help us with many other aspects of the game. We also used it as a wedge to cross the barrier with, an arm to scoop balls out of the corner, a stinger for triple balancing, and we could use them to tip the bridge to the other side of the field to help our partners get on the bridge.

Re: Bridge Manipulator
 

We initially used two arms driven by window motors, but found out in week 1 that that was not going to fly due to the increased weight of the bridges vs. our practice bridge. Prior to Queen City we re-engineered the arms to be driven by a single AndyMark PG71 gearmotor (from the kit) using a 45/20 gearset (am-0129) as a reduction. The arms were mounted on hex shaft, the design was bulletproof!

Re: Bridge Manipulator
 

We used a single piston driven, link bar, wheeled manipulator. Honestly, it was our 4th iteration of the design. It worked perfectly all season.

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At the GSR regional we had a Minipulator that ran off numatics, it worked well and consistently the only problems was since we were very close on weight (119.9) we could not put the air compressor on the robot therfore with all the other numatics being used we could only use the bridge minipulator twice before running out wich wouldn't work as in week one the balls would get stuck on the bridge. the other problem with this minipulator was it took alittle longer then what we would like.

Therfore before st. louis we came up with a new bridge minipulater thanks to 175 Buzz for the idea. The new minipulator was a triangle with a curved arc were the bridge and minipulater met so it would slide nice and easily. This was powered by a window motor. this worked very well as it was quick, consistent, we could use it as much as we needed. and it saved us some weight

Re: Bridge Manipulator
 

We used a pair of arms with a non-parallel 4-bar linkage powered by a pneumatic cylinder that was connected to the frame and one of the bars. The two arms were synchronized with flow controls and linked with an aluminum tube with a blue pool noodle covering it (we empirically determined that blue was the optimal color due to its inherent durability as a result of quantum chromodynamics).

The 4-bar linkage was designed (by me:D ) using wood, bumper pins, and a drill-press. The wood version was then re-created using 1x1x.125 Al box tubing and a piece if the kit-bot channel which was then mounted to the frame (actually, when it was initially mounted, some of the wooden parts remained, this made it easier to prototype the actuator mount, which was not done by me).

It was an incredibly rugged design that took all sorts of abuse and damage and it never stopped working. I wish I had a montage of all the abuse it took. In one mach it got caught on the bridge as the driver was turning and bent way over to the side and it bounced back nearly all the way and was still functional. In another match (or was it the same one?) the robot fell off the bridge and about half of the robot's weight landed on the arm's "elbows" and they suffered no damage. In eliminations at the Boston regional, it was used as a wedge (despite being nearly vertical) to lift a bridge. That bent one of the bars, but it didn't interfere with it's motion. In St.Louis it received even more cosmetic damage and we replaced one of the most bent bars as a preventative measure after the bridge got lifted up into the arm While the arm simultaneously rammed the bridge.

Not only did the arm act as a bridge lower-er, but it also could act as a ball corral-er, and a stabilizer to facilitate single balances and double balances with the robot facing outwards (since our COG was towards the front, if we were facing inwards we were already sufficiently stable without it).

http://www.youtube.com/watch?v=PqLQ8...&feature=share

Re: Bridge Manipulator
 

We designed our robot to be back-weighted so that it could hang off of the bridge during triple balances. Nothing in our drive train's design has physically prevented our robots over the past couple years (except probably 2007's and 2009's) from performing wheelies. This year's weight distribution just made it particularly easy. To answer your question, our robot originally did have a bridge manipulator. However, about two matches into the Orlando Regional, we realized it was much easier for our driver to wheelie onto the bridge. It was a no-brainer for us to remove the bridge manipulator, which gave us the extra weight to bring the total number of wheels on our shooter back up to five.