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Will you use PVC in the final??

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ya. we are worryed about weight

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can you get the ball out with out turning it on

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You do know you cant be touching the ball as the robot crosses your finish line right? If the ball if in contact with your robot while crossing you dont get the 2 points for the ball, just the 2 points for the robot. It needs to have some way to let it go easily.
Joey

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Looks to me like the whole mechanism rotates back under the power of perhaps one or two Window motors (Or Keyang, or Van Door).

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you might want to consider something a little stronger then PVC pipe fixtures. We used some last year and it snapped like toothpicks.

Our team moved to copper fixtures this year, they don't weigh to much more and they are strong as hell.

You also have to worry about getting tangled up with other robots. It could become a large tangling hazard if it drops on top of aother robot. Says somewhere in the rules that that's not allowed. you might want to reconsider that.

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maybe you guys could try thin walled (1/16"?) aluminum tubing that is round and use that?

I understand that pvc is very, very easy to build with. At any rate, good luck. :)

-Vivek

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i see you're using screws... by the looks of it
you might want to use PVC Cement to give the structure rigidity at the connecting joints without screws [might also alleviate weight]

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While this would make it stronger, repairing the robot would be very hard. Attaching everything together with screws allows for easy switching of parts if a length of PVC breaks (which may be a recurring problem).

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Wait, are you guys saying that we shouldn't build our robot with PVC? It's too fragile, it's too weak, it'll break? Maybe we should redesign our robot then. Oh, I'll let Bill Beatty from Team 71 know too. I think they have a couple national championship robots that used a whole lot of PVC...

When used properly, PVC is an extremely light, strong, compliant (and cheap!) material for use on a FIRST robot. I have seen a lot of PVC parts bend at some extreme angles, and return to their original shape. Aluminum parts don't seem to like such usage.

I would recommend the glueing method of attachment over the bolts.

Bengineer

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Actually...

There is another champion who used PVC for a key part. Don't let the yellow paint on the arm of 330's 2005 robot fool you; it's PVC. And there is nothing wrong with screws; the same robot's gripper was held on with screws. See this picture. Lower right has the connections in question.

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In my experience, thicker PVC (like that on the robots previously mentioned) is fine, but what they are using (flag-holder-esque thickness) will sometimes have issues when hit. I would reccomend the screws, if for no other reason, replacability. Also, I would have plenty of extra PVC on hand if you stick with it.

Good luck, the design looks great. How fast/controllable is it with those wheels?

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heh,
yes it is agreed that it is light, very strong for its weight, and cheap [and very good for prototyping], high-speed impact situations such as ones that might possibly occur in this game would not bode well for any arm made of PVC

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How much does your robot weigh? Do you have any bumper ideas?

How long does it take for your manipulator to capture the ball? Release the ball?

Interesting drivetrain.. do all six wheels drive?

-q