BEST Tetra Grabber

[monstermike]

Now that all of the regionals are over, 1) Who do you think (has the best Tetra Grabber? 2) Who has the most unique? 3) Who's has the best hold on the Tetra? Please do not nominate your own team.

[Pierson]

I only saw teams at the So. Cal. regional... but Team 980 had an awesome robot and tetra grabber. They could drive by the auto loader and spin the column/post on which their arm was mounted. This meant they could pickup tetras at full speed. As they were still in contact with the colored triangle.

[Kyle]

Team 007 had an amazingling cool gripper.

[Ianworld]

I've seen a lot of tetra grabbers I guess. There are a couple categories I guess and they depend a lot on how the tetra lifting mechanism works.

I'd say the best simple stab through design is probably swampthing's(179). To be honest is similar to my team's just a couple of prongs forward with a solid cross beam is all you need.

There are also the crane designs that grab the tetras through the top. team 38's had a great hold on the tetra and was an amazing design. The other great design i've seen is on good ole beatty(71). Their integration with their tetra grabber and storage area is very effective. I'd say that these designs are far from perfect in general though. THe tetras often sway quite a bit and are hard to place on the goals.

The final category is the dumpers. Most of these would stack up 2 to 4 tetras and dump them all at once on a shorter goal. I saw a couple good ones that did this, the gaelhawks(230), team 1402 and 381(i think...). 381 stood out because it overcame an issue with most of these tetra grabbers by really strongly securing them before dumping them. Something necessary when you become a goldmine of points and a target for all the opposing bots.

The most original and ambitious is probably wildstang's(111). Their double forklift side lifting design is quite amazing to watch in action(even on a crummy feed). It doesn't secure tetras tightly or provide an optimal method of delivery, but it is quite iimpressive in its ability to rapidly grab tetras.

A special mention goes to 865. A very very cool, methodic capping mechanism. It would store up a bunch over a long arm, and from what I could see on the feed, extend them up, unlock them, and flip them onto the goals. They had some issues, but defenitly the coolest! Not to metion it was paired with a swerve drive.

In general the succesful designs i've seen secure the tetra in some manner, either by clamping over it, pulling it in tight to their robot, or just gripping it in a manner that doesn't let the tetra bounce all over. The other key was being able to easily place them onto a goal. A team that easily places tetras onto goals is 121 the Rhode warriors. Their gripper keeps the tetras from moving around and locks the tetra in its orientation. The result is that they can rotate the tetra onto the goal. This defenitly eases teams abilities to cap tetras. The final key design was capping stored tetras seperatly. Not many teams can do this in a quick effective manner, but those that can like 71 are very succesful.

Looking back at this post i've defenitly spent way too much time watching FIRST robots in action .

[sanddrag]

Yes, I think 980 was one of the most unique. I can't point to a specific team but I think the most effective were those that acitvely grabbed the tetra rather than the tetra just sitting on something.

One of the most creative arms I saw was at the LA regional. At the start of human control, the robot went to the human loading station and the human player hooked a tetra in and then pulled (telescoped) the arm out to make it nearly twice as long. It stayed this way for the rest of the match and went on to cap several tetras. No pneumatic or motor actuation needed for the reach. Just a single pivot.

[slickguy2007]

I really liked 237's design a lot. When I saw it at NJ I thought it was pretty cool. Especially the way they went to go pick up that vision tetra.

I also like 135's rake design too. It was highly effective which made them a great alliance partner in finals.


GO 1403!!!

[Cory]

Active tetra grabber-173
Passive-20/254

[Stephen Kowski]

KISS.....25 & 179 have very effective passive grippers though at the high speeds both teams move, it is sometimes a safety issue but i like the designs anyways....

[lynca]

To add to versions of the tetra grabbing mechanism,

The pivot (yaw) or turret action while the robot is moving is a very crucial feature to success,

476 had a decent semi-turret
57 also had a well designed pivot motor, similar to 71

these robots can be pinned but still function because of flexible arm movement,

Also, the roll over arm seems to be quite effective as well
233 and 231 are good examples,

[Holtzman]

The best gripper I've seen first hand is that of team 188 Woburn Robotics. Its capable of grabbing 2 at a time and dropping them individually. See this thread about it http://www.chiefdelphi.com/forums/sh...ra+grabber+188

Other than that, very simple designs seem to prevail this year. A simple t-bar seems to work quite well.

[Pierson]

Originally Posted by Holtzman

The best gripper I've seen first hand is that of team 188 Woburn Robotics. Its capable of grabbing 2 at a time and dropping them individually. See this thread about it http://www.chiefdelphi.com/forums/sh...ra+grabber+188

Other than that, very simple designs seem to prevail this year. A simple t-bar seems to work quite well.

While it is cool that they can pickup 2 tetras at a time there was a minor flaw in the elevator system. During the (I believe) quarter finals in LA, a force was applied to the tetra grabber by pulling down and away from the robot by an opposing team. The top of the elevator mechanisms came off of the robot rendering them useless for the remainder of the match. It was fixed in time for the next round. I think if they had designed it a little simpler by using less string and metal that was a little more structurally sound, this might not have happened.

[Bharat Nain]

Team 56 had the best grabber I have seen. It is incredibly simple and works perfectly everytime. Team 103 is another one that can keep a good grip on the tetras.

[Brant Bowen]

I would have to say that Team 16 had the most unique gripper I've seen. It is hard to explain, but it is basically a curled piece of PVC or something that just spins the tetra into it and out of it as needed. I was amazed at how effective it was when I saw it too. If anybody knows, how did they think of it?

[chaoticprout]

At the So Cal regional I thought team 69 and 330 had awesome tetra grabbers. Only seen one tetra fall off 330 and none off 69. Congrats!

[dlavery]

Originally Posted by Brant Bowen

I would have to say that Team 16 had the most unique gripper I've seen. It is hard to explain, but it is basically a curled piece of PVC or something that just spins the tetra into it and out of it as needed. I was amazed at how effective it was when I saw it too. If anybody knows, how did they think of it?

Just look at a corkscrew. Yes, it is an amazingly effective and simple way to grab tetras, and probably one of the most innovative solutions to that particular problem that we have seen this year. Kudos to the Bomb Squad for their creativity!

-dave