Round Robot(s)

[jacob9706]

Originally Posted by Levansic

I'm curious about your round bumpers. On our prior round robot, we laminated 5 layers of a 5/32" mahogany plywood, dry, to make our ~14-1/2" radius bumpers.

This year, we needed a tighter 8" inside radius. We also wanted a very light bumper to aid in climbing. To get this, we made a birch-balsa-birch sandwich, similar to what was used in the brittish DeHaviland Mosquito bomber of World War II. We had to soak the birch for over two days to get it pliable enough, and then had to let everything dry on forms before laminating. This was a LOT of work, and took the efforts of ten students from start to finish. We learned a lot of ways to miscommunicate ideas and instructions.

Your curved wood is very uniform and clean. What did you use to get this great result?

What the students did was hook a industrial vacuum bag to a compressor and bent the layers with that. They pretty much glued them together, stuck them in vacuumed the air out and let it sit for a day.

[DjMaddius]

Team 2620 isn't round nor a rectangle *hint* corner climb *hint*

[orangemoore]

Originally Posted by DjMaddius

Team 2620 isn't round nor a rectangle *hint* corner climb *hint*

Are you a pentagon?

[DjMaddius]

Originally Posted by orangemoore

Are you a pentagon?

No sir, we have 8 'sides'

[nathannfm]

Another picture with finished bumpers in competition, looks like those might even be reversible with that seem down the middle.

http://www.flickr.com/photos/daniele...n/photostream/

[cmrnpizzo14]

Out of curiosity, is there really that much usable space created by using a round robot as opposed to the standard polygon shape?

[lorem3k]

Originally Posted by cmrnpizzo14

Out of curiosity, is there really that much usable space created by using a round robot as opposed to the standard polygon shape?

Let's assume a circular robot and a rectangular robot with the maximum allowed frame perimiter (112 inches).
For the circular robot C = 2πr. Since C = 112, the radius of the circle is 56/π or approximately 17.825 inches, and it's area is πr^2, which is 3161/π or approximately 998.220 square inches.
For a rectangular robot, we have 112 = 2l + 2w, and A = lw, or A = l(56 - l). With some calculus, we can find that the maximum area occurs when the robot is a 28x28 square, with an internal area of 784 square inches. In other words, a circular robot can have up to about 28.339% more usable area inside it's frame perimeter than a rectangular one.
You could run the numbers for any other polygon, if you really wanted to, but I'll leave that up to you (I'm too lazy). You'll find that as you increase the number of sides on your polygon, the maximum area will approach, but never reach, that of a circle with the same perimeter.

As for how useful this extra internal area is, that can only really be answered on a case-by-case basis by each time based on how much space their subsystems use.

[cmrnpizzo14]

Originally Posted by lorem3k

As for how useful this extra internal area is, that can only really be answered on a case-by-case basis by each time based on how much space their subsystems use.

That's more of what I meant, I understand the calculus behind it but I was curious if the teams using it actually found that they have more space to place things or if it seemed about the same as a polygonal frame.

[lorem3k]

From a strategic perspective, a circular robot would be harder to block, because any typical rectangular robot would just kind of "slide" to one side in a collision (though on the flipside, this would also make them less effective as defense robots).

From what I can see in the pictures of 2836 and 4743, there seems to be a lot of unused space inside their perimeter, but their robots don't seem to do a whole lot. I don't see any shooter on 2836's bot, and 4743's just looks like a simple 1-point dumper. I think they'd be able to use more of that space if their robots had more functionality, i.e a floor pickup or a 30-point climb.

Sorry if this post sounds harsh towards these two teams. I don't intend to put your robots down, just making some observations about how you've used your internal space.

[mocibot]

Originally Posted by DampRobot

Thirded. How are you supposed to make a truly round robot? The world's largest lathe?

1829 has a round robot this year. As to how we made the bumpers, a ShopBot(CNC router). The ShopBot got here about a week ago, so that was interesting. Looking forward to competition in Richmond tomorrow!

[Gaiice]

Originally Posted by nathannfm

Another picture with finished bumpers in competition, looks like those might even be reversible with that seem down the middle.

http://www.flickr.com/photos/daniele...n/photostream/

The bumpers are reversible, I sewed them with the seem down the middle.

Originally Posted by lorem3k

From a strategic perspective, a circular robot would be harder to block, because any typical rectangular robot would just kind of "slide" to one side in a collision (though on the flipside, this would also make them less effective as defense robots).

From what I can see in the pictures of 2836 and 4743, there seems to be a lot of unused space inside their perimeter, but their robots don't seem to do a whole lot. I don't see any shooter on 2836's bot, and 4743's just looks like a simple 1-point dumper. I think they'd be able to use more of that space if their robots had more functionality, i.e a floor pickup or a 30-point climb.

Sorry if this post sounds harsh towards these two teams. I don't intend to put your robots down, just making some observations about how you've used your internal space.

The circle fits our shooter right along the edges, this is a shooter. Our circle robot is not a 1-pt dumper. Check us out at Troy, now that we have our programming worked out, your opinion will definitely change.

[Koko Ed]

Originally Posted by Marc P.

Not quite round, but octagonal!

(we do have a shooter, just wasn't ready in time for Suffield Shakedown.)

It's a Battle Roomba!

[moonlight]

Here is a picture of our FIRST alliance at the Portland Autodek Regional. In the picture is clear that we are indeed round.

[Garrett.d.w]

Originally Posted by moonlight

Here is a picture of our FIRST alliance at the Portland Autodek Regional. In the picture is clear that we are indeed round.

I'll second that it is indeed round, they were really fun to watch
The nerd inside me really loved it when they spun with their lights on

[lorem3k]

Originally Posted by Gaiice

The circle fits our shooter right along the edges, this is a shooter. Our circle robot is not a 1-pt dumper. Check us out at Troy, now that we have our programming worked out, your opinion will definitely change.

Do you have any other pictures of your shooter from a better angle? From the ones in this thread, I'm having trouble seeing how your frisbees can get the air to make it into the other goals, unless your shooter's angle is adjustable.