How are you picking up the tetras?
 

Are you picking it up from the top (crane)

Bottom (forklift)

Other...?

Re: How are you picking up the tetras?
 

We are picking up from the top and then sort of swinging it out so we are grabbing it from the bottom corner. It works well, and it saved us some major arm height.

Re: How are you picking up the tetras?
 

We're picking it up from the top with a cross-like structure, positioning it over the goal, and lowering the tetra while driving backwards.

Re: How are you picking up the tetras?
 

Levitation is definitely the way to go.

I'm telling you.

Re: How are you picking up the tetras?
 

we're picking it up from the top.

:)

Re: How are you picking up the tetras?
 

We're picking it up from the top, and then rotating it back so that it effictivly grabs it as if we grabbed at the bottom. I think thats the easiest way to explain it.

Re: How are you picking up the tetras?
 

We grab it at the bottom, which saves us a lot of time and adds extra length to our arm. We can cap about8 tetras on center goal without needing any extension. However our grabber is not a forklift. It just grabs the bottom corner.

Re: How are you picking up the tetras?
 

I'd start by moving my eyebrows and asking it "How are YOU doin?"

:)

As Daniel describes, his team's robot seizes the Tetra from the apex. The result is a tetra that is unitized with the arm.

Re: How are you picking up the tetras?
 

Our team picks it up eathier at the top, or in the middle of it. Eathier way works well, but holding it in the middle gives us more height.

Re: How are you picking up the tetras?
 

This is basically our grabber from a top view:
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\------------------/
\---------------/
\-------------/ edit: the spaces didnt show up
|------------| it is a triangle at the end of
|------------| a bar, this forum doesnt like
|------------| text art very much, oh well
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It slides under the top and nestles in the endcaps where all the sides meet. This also centers the tetra automatically on the gripper.
We cut it out of solid 1" thich aluminum, it took about 30 min of straight cutting, and a ton of cutting grease also.

Re: How are you picking up the tetras?
 

http://www.chiefdelphi.com/forums/sh...ad.php?t=34995From inside (but top corner)

Re: How are you picking up the tetras?
 

The claw
The claw decides our fate.

Re: How are you picking up the tetras?
 

Other :D
But then again you may say it fits in one of these catagories Elgin since you saw it Saturday.

Re: How are you picking up the tetras?
 

We get into the apex and as the arm goes up the tetra rolls back and nests on a brace that touches the tetra in five places including an eight inch span across the bottom. The first one we built used a tennis ball in the apex and worked well but we redesigned and built a better and stronger one. We don't know if we want to use a ball on then new one or not.

Re: How are you picking up the tetras?
 

We use a simple hook to grap the tetra by the apex.

We decided against the use of a complicated, actuating mechanism because we would figure that it would take more time and precision, as well as having to lift more weight on the end of a cantilevered arm.

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.