"It's the Claaaawww"........ prototype.
 

Here are a couple of quick clips or our prototype claw. The final will be much lighter and the action will be faster. The beauty of prototyping it is we found some very interesting mods that really make it work well.

http://www.youtube.com/watch?v=QMjZ1swhchc

http://www.youtube.com/watch?v=wMU7VPON7M4

Re: "It's the Claaaawww"........ prototype.
 

That's a super nice prototype. Good enough to be the real thing.

Re: "It's the Claaaawww"........ prototype.
 

Yep, I've said the same thing!
But there is a little problem. One of our team "rules" is:
No wood on the robot!!

Some rules are made to be broken.:ahh:

Re: "It's the Claaaawww"........ prototype.
 

That looks awesome actually. Fantastic work by you and your team! Are you planning on making the final version out of aluminum or polycarbonate?

Re: "It's the Claaaawww"........ prototype.
 

Yes. The fingers will be polycarbonate and the linkages will be aluminum.

Re: "It's the Claaaawww"........ prototype.
 

she's a looker, thats for sure. For some reason a lot of robots this year look awefully violent...it's awesome.

Re: "It's the Claaaawww"........ prototype.
 

neat prototype!

We have a rule: We make no rules about what materials we can use, the GDC does that for us. Our 2009 robot was made mostly of plywood and plastic pipe, and it was the most effective robot we have made. It even had a couple wood 2x4s in it!

Our prototype has two pieces of plywood also, but they work differently. We used a pneumatic, outside, single point grabber in 2007 and were not real pleased with it, even after a redesign between regionals. We're going for the inside grab this year, wish us luck! and when we get it actually grabbing a game piece under computer control, we'll put video up.

Re: "It's the Claaaawww"........ prototype.
 

What was wrong with the outside grab that year?

Re: "It's the Claaaawww"........ prototype.
 

There were two problems. We did not anticipate how variable the tube inflation would be, and the claw just did not get a good enough grip on tubes that were a bit soft. The second problem was that the tubes could move sideways, they did not want to stay properly oriented.

I think the inside claw will help with both of these problems. This year the goal pegs have a much smaller end cap, so the tube placement action will be different, and more appropriate for an inside grabbing claw.

For the original poster, I suggest you have the students try to shake the tube off the claw by moving the "arm" sideways as if it were on the robot, and the robot were maneuvering as robots do in real games. See if you can hold onto the tube, and that the tube does not move around too much. It could be that this design does work just fine.

Re: "It's the Claaaawww"........ prototype.
 

Since it was my freshman year in 07 and we did not travel to Atlanta that year, I didn't see many other robots from that year. What other teams were there who had inside grippers? The only one I had any knowledge of other than our own was 25's. I definitely liked that robot haha :)

Re: "It's the Claaaawww"........ prototype.
 

If I recall correctly, both 47 and 33 had "inside grippers," with Chief Delphi using a bucket cut in half as part of their end effector.

Re: "It's the Claaaawww"........ prototype.
 

Haha that's awesome, we cut ours from a bucket too! Now I gotta go find some pictures of their bots.

Re: "It's the Claaaawww"........ prototype.
 

My big concern with an "inside" grip is lining up the gripper on the tube - that seems a lot harder than driving into a tube and "chomping" it.

Re: "It's the Claaaawww"........ prototype.
 

We didn't have an inside gripper in 2007. It pinched around the side of the tube from the outside.

Re: "It's the Claaaawww"........ prototype.
 

Yes, it's an important concern. We're using the approach of having the pivots for the "fingers" far apart, and the fingers close together to form a dull triangle when the gripper is not gripping a tube. Then this "point" can be used to help guide the tube and gripper together, so aim is not very critical after all.