pic: Claw^2 Concept

[CD47-Bot]

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[Sachiel7]

So, any questions, comments?
I'd be glad to assist with any information.

[T967]

I wonder what those claws are made of?

[Sachiel7]

We're toying with several ideas.
Either aluminum extrusion that's not as curved or aluminum flat bar heat shapen. I'm leaning towards the flat bar. The bottom 2 "claws" are fixed nice and tight to the arm. The top one pivots via a piston.

[WakeZero]

Originally Posted by Sachiel7

We're toying with several ideas.
Either aluminum extrusion that's not as curved or aluminum flat bar heat shapen. I'm leaning towards the flat bar. The bottom 2 "claws" are fixed nice and tight to the arm. The top one pivots via a piston.

The hardest part we found when building our arm was getting it rigid. You may want to experiment with having two support bars instead of just one pole. We found this helped with making the arm rigid

Good luck!

[Gui Cavalcanti]

Hey man, looks cool! Can't wait to see it at VCU!

May I suggest PVC for those gripper claws? It bends nicely and is one of those replaces-in-a-heartbeat kind of deals

You guys have a full practice field with carpet? I remember you said something about that earlier... we're getting to the point where we may definitely want to scrimmage

[Madison]

What use do you plan for the two sets of extending horizontal bars that lie opposite the claw on, presumably, the back of the robot?

Also, are you worried about tipping?

[Alex Cormier]

what wheels are you goin with? how well do they turn in high gear? how well do they go up the 6" step?

[Sachiel7]

Ok, plenty of questions, so I better start answering
1. We don't have a practice field. We were planning on building one, but time and funds ran too low. We're currently hooking up with local teams for practice. We may get around to building a mobile goal, but nothing more.
2. We aren't touching the platform, bar, etc. Our drive is 36" wide, so don't expect to see us trying to get up on the platform, however, we think we might be able to get up from the side onto the 6" platform to block bar grabbers. We are using 8"x2" Vulcalite Wheels. They can be found here:

http://arrter.4casters.com/Parts/Def...tyCode=ARWHEEL

3. Our main strategy is Ball Control. Capping (we originally only wanted to cap the mobiles, now we're going with both), herding, and working with the mobiles, such as grabbing them. We also have our arm long enough that we can grab the center 2x ball from the side of the platform.
4. Tipping. It's one of my primary worries. This arm is going to be on the front of our bot and extend roughly 7 feet in front of it. Now, the arm itself should be very lightweight. Or at least, we're trying to make it that way. The base arm that doesn't pivot is the 2x4 extrusion in the kit, the 2nd arm is 1.5" square extrusion, and the final arm is the 1" aluminum pipe in the kit.
We're using a combo of the van door and pneumatics to drive the arm.
We're either going to have a tip-plate at the front of our chassis (a solid plate extended out at an angle to stop the bot from tipping) or we're going to rely somewhat on our goal hooks. Either the hooks will flip us back up, or they will help brace our weight against the goal's platform to help prevent tipping.
5. As I said before, we're using 8"x2" Vulcalite wheels. We're running off of a sprocket and chain system off the CIMs geared down 18:1. This is the same drive system we used last year, and it served us well. The drive and chassis are complete. Parts are currently being farbricated for our plow and arm, and assembly will follow.

We will be at the DC Practice event, so you can catch a glimpse of us there. If you would like to hook up for a 1:1 practice day, then PM me and I'll see what we can do.