How are you picking up the tetras?

[Peter Matteson]

Originally Posted by tiffany34990

but how many can pick off the floor, auto loader or dependent on the human station????

We can...

[rocknthehawk]

We can also pick it up from anywhere. Our first claw was a simple ball with a shovel at the bottom, but we tried it and it wasn't as easy as we wanted it to be, so we designed a new claw. Here's a pic of it (after we painted it).

[Daniel Brim]

Originally Posted by tiffany34990

but how many can pick off the floor, auto loader or dependent on the human station???

We can as well, although the most efficiant way is the human player. Here's a picture of our claw.

-Daniel

[Greg Marra]

Originally Posted by DanielBCR

We can as well, although the most efficiant way is the human player. Here's a picture of our claw.

-Daniel

We had this idea too. We figured it'd be quite difficult to line up the grabber in the xy plane to pick up tetras from the floor and to score them, so we ultimately went with something different.

How well does your grabber work in terms of lining itself up right? We had a triangular guide in our mock up to help guide the three fingers into the right places.

[Mullen]

our team was going to go for the simple hook method, but since we thought of it so quickly, we figured everyone else did too ...which turns out to be true...
so we decided to spice things up. our gripper holds all 3 sides facing you off of the auto loader. first we line up by touching the bottom, then we grasp onto the two sides, this gives us much more control of the tetra so we wont lose it while running around the field and getting hit by other bots.
also, it has a certain coolness effect to it, maybe the movie Tremors will stir up your imagination .. we'll post pics later

[Rick TYler]

Originally Posted by BurningQuestion

We use a simple hook to grap the tetra by the apex.
(...) The drawback to this type of tetra grabber is that we have less control over the tetra, and it tends to swing around a little bit. We are planning on adding a horizontal beam to the hook that will keep it from sliding down the arm too easily, and to hopefully steady it a bit. Non-actuating hooks work well, but only if you design them right.

The most efficient tetra manipulator we developed in mock-up used a skewer with a cross bar behind and slightly below the arm beam. We also found that the skewer worked better when tilted 5-10 degrees upward. So far, I've seen lots of skewers with crossbars -- some powered at the wrist and some fixed -- but only a couple that include that tilt.

Ironically, our team voted on a different manipulator in part because the fixed skewer was too simple. Some teammates wanted to be able to flip the tetra over and carry it over the body of our 'bot, others thought it the skewer would require too much reduction in the arm lifter, and, more importantly, it would have made the pneumatics team unemployed.

[Bcahn836]

We are using a claw, it looks a little different now that we had to lose some weight but the idea is the same. It uses a 6 inch pneumatic cylinder to rotate it up or down to pick up and release the tetra. This makes it easy to pick up a tetra from the ground, manual loading station or the human player.

[Eric Yahrmatter]

We use two plates: 1 that is stationary and one that moves. The moving one goes inside the tetra and lifts it into the other plate like this:
Buzz X

[Michael Corsetto]

We originally went with a forklift design for our grabber. But when we got to competition, we found it was to hard to line up to the auto loader and it was not compatible with the human player.

So on Thursday of SAC we came up with a pneumatic that pushes out to hook the tetra, then retracts to let the tetra slide off. But the pneumatic shaft got bent. So down goes design numero dos.

Our third (and luckily final) design is a simple hook with rods coming out either side to stabilize the tetra. It works reasonbly well, but it isn't as good as a well thought out grabber would be. Everything turned out ok though, we played defense for our alliance and got to the finals for the first time in our team's ten year history.

[nightrenegade00]

Our robot has the ability to pick up tetras off the ground but we barely use it. For any of you who have seen our robot you'll know that we depend on our human player to load us up with up to 3 tetras and cap like a maniac.

-Crash

[Captain Rich]

We spear it with a piece of pvc, then lift it with a forklift like lift mechanism. It is easy to aim for anywhere inside a tetra and then lift.

[shamuwong]

We use two servos to extend an arm with 3 fingers that can pick tetras up off of the ground, auto loading station, or human loading station. The entire mechanism can be extended up to 17 feet in the air with a 4-stage telescope with self-contained pulleys.

See: http://www.chiefdelphi.com/forums/sh...ad.php?t=36329

[Validius]

Originally Posted by shamuwong

We use two servos to extend an arm with 3 fingers that can pick tetras up off of the ground, auto loading station, or human loading station. The entire mechanism can be extended up to 17 feet in the air with a 4-stage telescope with self-contained pulleys.

See: http://www.chiefdelphi.com/forums/sh...ad.php?t=36329

ur machine kicks serious bot (when its not leaving its lampshade on one of your home goals)

I would love to see an exploded diagram of your lifter.

[JMH]

Team 1370 can pick up the tetra from the bottom or from the top we have to different grippers we find that it is much faster to pick it up from the top but you sacrofes how high you can go.

[Koko Ed]

The claw
The claw decides our fate.