From the pictures being posted this is looking like it will be the year of the C style claw for grabbing tubes.
Yep. But not all roller claws are created equal 
I totally agree i think 148 has a killer design. Where it opens up to release the tube. I do not know why, but it brings back memories of 47’s 2000 bot when it opened its mouth to drop balls. 47’s 2000 bot was years a head of most teams.
We are using the platter type of manipulator, where a part goes under the tube, then the top clamps down on top of it.
We shall have to see which one is more effective, but I get the feeling that it will end up being the roller claws 
I don’t know, Grim, we’re using a design that sounds a lot like yours, with a wide, curved plate that goes under the tube and and claw that clamps down on top. Once we got it working at the Suffield Shakedown, we found that we had no trouble whatsoever picking up tubes from the center of the playing field and that it held them very securely. With practice, our driver is now able to release the tubes quickly and spin away from the rack. We hope to add a four inch “bump” that lowers the claw slightly upon release, making it even easier to place the tubes on the rack.
The first thing we did after kickoff was watch Einstein from 2007, our design is loosely based on the Pink Team from that year. The roller c claw is pretty slick… Hopefully we are able to be as successful!
I have doubts. The pistons came today, the robot is already shipped. We never tested the pistons with the claw. My worry is that there won’t be enough grip.
We used the same style of roller claw as we did in 2007. Apparently, our claw was pretty good that year. Of course, nobody in 2007 saved documentation…
we have a roller claw, but it isnt a C, its a 30 inch long V, the tube gets wedged in tighter the higher the amperage cutoff on our roller. the roller is 6 inches in diameter, but is not directly connected to the axle, instead rubber bands act as spokes, and allow our claw to pick up tubes with a ± 1.5 inch variance from nominal.
Our is not a c claw, instead it uses a fork to grip from inside, like inverse chopsticks. It will pick up a fully deflated tube from the ground.
We are using an internal gripper. It is in a C-shape, but it spreads on the inside of the tube. In 2007, our C-Claw caused a lot of slippage.
I guess our claw is in some ways very much a C claw, but in use it is different. It is attached to a short arm which is attached to our lift/elevator/ladder. However, the bottom part of the claw is an extension of the arm, and the top “jaw” is what really moves in a unique claw motion. Furthermore, the arm is shaped so that when it is in the lowest position, the lower jaw is perpendicular to the floor and it “bulldozes” the tubes. The upper jaw swings down and clamps from the inside of the tube. When we lift our arm vertically, the tube is already in a vertical hanging position.
Thanks for the poll, it’s a great idea!
A. I think there is some confusion on what is meant by a ‘C Claw’.
B. I also think that the key to a successful tube scoring is manipulation, whether that comes from rollers or from arm articulation.
Completely static tube manipulators will see trouble, methinks. Otherwise, there is more than one way to skin this particular cat!
I would say that a C-claw is a grabber, hand, or clamp like mechanism with 2 jaws. Specifically, it grabs onto the cross sectional tube of the game pieces. It would not grip/adhere to it with rollers or scoop it and press on the top and bottom faces of a game piece that is lying on the floor (“pizza platter”).
I would say this is a clear C-claw: http://www.chiefdelphi.com/media/photos/36495
Debatable, but yes (has only one moving jaw, correct?): http://www.chiefdelphi.com/media/photos/36531
No (roller): http://www.chiefdelphi.com/media/photos/36542
I think from the original poster’s comments, he was meaning the C-shaped roller claw (like the third link you posted), though I could be wrong.
Regardless, I think the two most common types will be the C-roller, and the clamp with two jaws like you described. I guess they could both be considered “C claws”, so it really could be the Year of the C Claw.
Ours is similar, although I don’t know about being able to pick up a **completely **deflated tube.