Poll: Wide or Narrow Chassis?

[MrForbes]

Originally Posted by kws4000

SQUARE. Meccano wheels actually work best with the rollers forming a "perfect" X. That is, the wheels should be in a square, hence square frame (Ether can verify this, I found some white papers of his but I'm too lazy right now to find 'em again.). It doesn't matter which end is front, but one end will have to be the front regardless. You can't swap a hole in the frame halfway through a match!

Square where the wheels contact the floor? or square at the outside of the frame?

Originally Posted by squirrel

Square where the wheels contact the floor? or square at the outside of the frame?

I think it only matters where the wheels contact the frame. One would just build the robot square as well to make it less likely to tip, or to make it look better.

[Mr. Pockets]

DonRotolo, you are a genius BAD is so good xD

On a more serious note to the people considering wide chassis for the potential for a wider BAD™, a word of caution. I had a bit of experience with working on a BAD™ and conveyor system a few years back. It is CRUCIAL that if you make your BAD™ wide, you have some way of funneling balls down to a more narrow path for whatever your scoring device is (unless your scoring device is very wide, though I'm not expecting many of those this year). The worse possible feeling in the world is building an excellent BAD™ and the game pieces getting jammed because the robot has no good way to shunt the pieces into single file.

[kws4000]

Originally Posted by squirrel

Square where the wheels contact the floor? or square at the outside of the frame?

Both. But at the moment i'm not totally sure what the mech guys are doing. All I know is that I'm tryng to prevent them from bashing up the encoders on last years bot as we dismantle it.

[Freedomsky]

Looking at the earlier calculations on whether three long robots could actually fit on the bridge, one little fact was overlooked. Three 38 inch long robots can fit on the ramp, indeed. But a robot built to its maximum dimensions will not be 38 inches, but rather more like 44 inches. Why? The bumpers are not included in the 38 inch measurement, so when you take into account the extra bumper space, you're going to have a little bit more robot hanging over the edge than you think.

The balance issue with a tall robot can be easily overcome. The simplest solution is to put the center of balance towards the bottom of the robot. With that, it will be much easier to avoid tipping. And a sideways robot can allow all three robots, even if the other two are long ways, to fit comfortably.

With that, long ways will be the best way in my opinion, because as we all know, every little second counts, and that second saved collecting that extra ball can give you those few extra points that you need to win nationals.

[Siri]

Originally Posted by Freedomsky

Looking at the earlier calculations on whether three long robots could actually fit on the bridge, one little fact was overlooked. Three 38 inch long robots can fit on the ramp, indeed. But a robot built to its maximum dimensions will not be 38 inches, but rather more like 44 inches. Why? The bumpers are not included in the 38 inch measurement, so when you take into account the extra bumper space, you're going to have a little bit more robot hanging over the edge than you think.

Actually, it looks like basically everyone's calculations (here and elsewhere) do include bumpers, or have been corrected to do so. Here, Don's nailed the 44" from the beginning:

Originally Posted by DonRotolo

Bot 2: Perfectly balanced, 44" long

That said, 3 long bots definitely does create a very precarious situation! It's certainly something to think about, though I think you'll find that virtually all teams otherwise likely to be strong elimination contenders will have realized this (and likely the benefit to collecting width-wise) and found a way to compensate. I won't claim this necessarily means driving wide.

Low CG is definitely always something for which to aim. (Unless the GDC ever forgets to specify the height dimension as being perpendicular to the floor.) However, I can't claim it's necessarily easy to achieve. It definitely can be if you have a non-existent scoring mechanism, an exceedingly light/low shooter, or Andy Baker. Us tall shooters will being paying very, very close attention to it.

Welcome to ChiefDelphi!

[Freedomsky]

Ah, I hadn't read past the first page. But thank you, I've used this site now for a long time, but just now signed up.

[Hallry]

Well, it has happened: The wide chassis count has surpassed the narrow chassis one.

[Ninja_Bait]

We, the long chassis voters, are now the minority that can, in the end, tell the majority "I told you so". (At least, I hope so. )

[DjMaddius]

Originally Posted by Ninja_Bait

We, the long chassis voters, are now the minority that can, in the end, tell the majority "I told you so". (At least, I hope so. )

I agree haha. Grabbing a ball in 11" (I believe thats what we calculated would be the space allotted for bringing in balls according to bumpers being 8" from either end or w.e) space on the narrow end just won't be enough. Using the wide side, you won't have to worry about that. You'll have plenty of space to grab a ball and bring it inside the bot without thinking about it in the heat of the game.

[CrashTestPilot]

Originally Posted by Siri

Low CG is definitely always something for which to aim. (Unless the GDC ever forgets to specify the height dimension as being perpendicular to the floor.) However, I can't claim it's necessarily easy to achieve. It definitely can be if you have a non-existent scoring mechanism, an exceedingly light/low shooter, or Andy Baker. Us tall shooters will being paying very, very close attention to it.

The height, length and width are relative. I learned that during our rookie season in 2008. Bomb Squad showed up with a robot that started the match in one orientation but drove around in another. I quickly learned that day what it means to think outside the box. I still think this is the most genious robot I have seen in person.

http://www.youtube.com/watch?v=bI_2UMEUbNw"]http://www.youtube.com/watch?v=bI_2UMEUbNw

[Siri]

Originally Posted by CrashTestPilot

The height, length and width are relative. I learned that during our rookie season in 2008. Bomb Squad showed up with a robot that started the match in one orientation but drove around in another. I quickly learned that day what it means to think outside the box. I still think this is the most genious robot I have seen in person.

Link

This was an awesome bot. But is it always legal? In 2008 there was no height limit and only a 80" diameter upright cylinder length/width limit. The bumper zone was also only defined in Playing Configuration. This year the bumper zone is "<R29> Bumpers must be located entirely within the Bumper Zone when the Robot is standing normally on a flat floor", though "normally" could take the "perpendicular" or "standard" definition.

[Sconrad]

Originally Posted by Freedomsky

Looking at the earlier calculations on whether three long robots could actually fit on the bridge, one little fact was overlooked. Three 38 inch long robots can fit on the ramp, indeed. But a robot built to its maximum dimensions will not be 38 inches, but rather more like 44 inches. Why? The bumpers are not included in the 38 inch measurement, so when you take into account the extra bumper space, you're going to have a little bit more robot hanging over the edge than you think.

Actually, DonRotolo included this number in his calculations. This does bring up another consideration into the equation though. I believe he had 21.5" of each robot on the bridge. Now, should the wheel on each 6 wheel drive robot be spaced evenly, that would put Bots 1 and 3 leaning on the inside of their center wheel pair. If I am not mistaken, that would make them likely to fall until their is only 20" over the actual bridge. I could be alone in this, but having 24" of my 44" robot and 4 of my 6 wheels hanging over a foot of thin air makes me awful nervous. On top of this, getting both bots 1 and 3 on the bridge without placing them there with a blimp bot (an idea tossed around in our team for a short while ) seems to me to be an extremely difficult, if not impossible. I hate to be close-minded, but I tend to side with soxfan269. If we see three long robots on a ramp, it will most likely be a monumentous, if not one-of-a-kind, event.

[MrForbes]

A wide robot on the bridge only partway would likely be a 4 wheel robot, with one pair of wheels hanging off the edge and the frame (or chains?) resting on the edge of the bridge deck, which is a relatively stable configuration

[Henzado]

We have decided to go with narrow body. We, as a team have decided that is very important to go over the barrier. A wider robot has a higher center of gravity, as compared to a narrow one.

The main point is a wider base means a likely chance of your robot taking a dive.