15-01-2008 12:27

Re: pic: Team 223 Chassis

Might as well be the first one to say this...

Have you all though about your CG? From what I'm seeing, that sucker is going to be tip-crazy, especially because of the wide-side drivebase.

15-01-2008 12:28

SgtMillhouse648

Re: pic: Team 223 Chassis

We had that problem in 06 w/Alice. was crazy top heavy. could score awesome when we weren't on our backs, but we spent more time over than upright....
Malhon

15-01-2008 12:30

Otaku

Re: pic: Team 223 Chassis

angled frame + back or side heavy + trackball = oh god, this won't end well.

Unless you weigh down the opposite side. Which you might not be able to weigh down enough if you can't make weight normally. If you can, pull a Quixilver and ziptie some rebar to your robot. It seemed to work alright for them...

15-01-2008 12:32

MrForbes

Re: pic: Team 223 Chassis

This paper

http://www.chiefdelphi.com/media/papers/1974

might help explain the situation...

15-01-2008 12:40

AdamHeard

Re: pic: Team 223 Chassis

Wow... cut them some slack.

I'm sure a team that's been around that long knows what CG is, and I bet that's only 50-60 pounds of what's going on the robot, you don't know how the rest is distributed. For all you know that could be all 1/16" wall and be much lighter than you are guessing.

114 of all people should know that being tall doesn't necessarily mean poor CG.

15-01-2008 12:45

Otaku

Re: pic: Team 223 Chassis

Tall doesn't mean high CG, no.

However, tall & offcenter does mean unfavorable CG, typically.

Lets say that there is 60lbs there. Add in the chassis weight, lets say 15lbs, evenly distributed, and the rest of the 120lbs (putting 45lbs) on the other side. Divide that 15lbs for chassis by two and you get 67.5 (woo hoo) lbs on one side and 52.5lbs on the other side. Add in the height, and it gets pretty bad. Then add in the dimensions and it multiplies the problem.

And that's in the best-case, from what I can see.

15-01-2008 12:47

MrForbes

Re: pic: Team 223 Chassis

I hear you Adam...but how about if you estimate the CG of the proposed design, and think about whether or not you'd recommend your team go with it?

And just because a team has been around a long time does not mean all the people on the team have been. Some teams lose their experienced members and don't have the depth of knowledge that is available on CD.

I also agree that being tall does not mean having a poor CG. Howerver, having that much extruded aluminum high up, off center, and on a sideways drive base with a very short wheelbase, is an open invitation to disaster. btdt

15-01-2008 12:48

Kyle Love

Re: pic: Team 223 Chassis

Guys...its the Pink Team, they can make it work.

15-01-2008 12:50

AdamHeard

Re: pic: Team 223 Chassis

I stand by my original statements. I highly doubt that 45 pounds is in that structure.

Considering that 1" square 1/16" wall is only .28 pounds per foot, I highly doubt there is any more than 10 pounds (and that's overestimating) in that structure.

As for it being off center, we have no idea what the rest of the robot is. It could have an arm that extends the other way and brings the CG perfectly in to balance.

And yes, not all old teams are capable, but a team capable of putting together a CAD that nice looking is most likely capable of setting material properties/weight and then going to view> Center of Gravity.

but then again, it's possible they used entirely heavy materials on the top while discovering some new amazingly light material to use on the base.

Until we get the details from 223, let's hold off on the immediate criticism shall we?

15-01-2008 12:54

Tottanka

Re: pic: Team 223 Chassis

/they better dont fall...i've picked them twice in the Fantasy First

15-01-2008 12:55

ChuckDickerson

Re: pic: Team 223 Chassis

Is that by chance 80/20 QuickFrame I see?

15-01-2008 13:02

MrForbes

Re: pic: Team 223 Chassis

Sure, I'll hold off on the criticism, and only stress the constructive.....

Last year we used a single 3" diameter, 1/16" thick round aluminum tube as a mast to support our arm. It worked very well, and allowed us to make a heavy drive base and a virtually untippable robot. Attatching the arm mechanism to the tube was fairly easy, once we figured out that we could make sheet aluminum brackets, and clamp them to the tube.

Making a drive base with the wheels going the long way results in a contact pattern of the wheels on the carpet that is about two feet square.

A pair of arms that are spaced about 26" apart will contact the ball about 4" off the floor. If they are activated as soon as the ball is fully on them, they might be able to lift the ball without the ball bouncing out first.

An amazingly light material is really nice for the upper part of the robot. An amazingly heavy material is really nice for the lower part of the robot.

Wheelie bars are not necessarily part of the chassis, they may be part of a mechanism.

15-01-2008 13:07

TD78

Re: pic: Team 223 Chassis

The Pink Team is 233, not 223.

15-01-2008 13:09

jjjeski

Re: pic: Team 223 Chassis

Just so you know, 223 is Xtreme Heat. 233 is the Pink Team.

We are team 223.

15-01-2008 14:42

jjjeski

Re: pic: Team 223 Chassis

Also, the chassis is not complete in the picture. We're still working on it now.

15-01-2008 15:13

sanddrag

Re: pic: Team 223 Chassis

Why is the chassis cut on an angle at the ends? There are no obstacles to clear and I'd think you wouldn't want to be riding up over other robots.

15-01-2008 16:01

Ben Piecuch

Re: pic: Team 223 Chassis

Clearly you've never been pushed back far enough to be stuck on an edge of your frame and whatever else is lifting the other end of the robot. The cutback ends allow the wheels to be in contact at any angle. But, with mandatory bumpers now, that point is moot.

Bengineer

15-01-2008 16:41

ChuckDickerson

Re: pic: Team 223 Chassis

From what I can tell from the photo I would be worried that this design (as pictured) would violate <R19> (no wedge bots) thus making it illegal.

Note that nowhere in the rule is there any mention of which way the wedge is oriented. Now your bumpers may fix the issue but since you are only required to have the bumpers on 2/3 of your robot it may or may not.

15-01-2008 17:28

Re: pic: Team 223 Chassis

It looks to be 1/8th. However, I don't know for sure, which is why I asked the team if they had done CG calculations. And we very well know that being tall doesn't mean bad CG; our 07 bot was 11 feet tall, and could tip to 60 degrees and still stand up.


This drive base looks very solid. Think the poster could take a screenie with Inventor's CG icon in it, maybe a few views slapped into a post could really clear it up for all of us.

15-01-2008 20:23

lukevanoort

Re: pic: Team 223 Chassis

It is 1/16". That is 80/20 Quickframe (or similar); you can tell by the little black connectors in the corners. I have no idea what the structure is for, but it should be pretty darn light.

15-01-2008 21:30

IbleedPink233

Re: pic: Team 223 Chassis

Thanks for the confidence, but no it is definitely not us.
Besides, when have you known the Pink Team to release genuine information about our robot before it is shipped? Never. Although, there may or may not be some revealing or pointless teasers coming some time in the near of distant future - so hang on to your seats.

16-01-2008 13:29

D_Price

Re: pic: Team 223 Chassis

What the heck is this...i am sry but did u guys think of the game or just did it...??? It is too top heavy.

22-01-2008 02:06

Eugene Fang

Re: pic: Team 223 Chassis

REBAR!!!!

17-02-2010 23:51

Hawiian Cadder

Re: pic: Team 223 Chassis

i dont think that cg would affect them in a normal game, going over the hump..... that changes things a lot.

17-02-2010 23:53

Akash Rastogi

Re: pic: Team 223 Chassis

*Ahem*

This picture is from 2 seasons ago

Please look before you post next time.

17-02-2010 23:53

Vikesrock

Re: pic: Team 223 Chassis

This thread is from 2008......