Ball size?

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Posted by Greg Mills.

Engineer on team #16, Baxter Bomb Squad, from Mountain Home and Baxter Healthcare.

Posted on 3/15/2000 1:58 PM MST




What was the condition of the balls at Great Lakes? It was hot at KSC and the balls were at the top of the spec. both ways. FIRST only attempted to keep the balls under the max. If a team challenged a ball before each match they would look at it and measure and replace if it was over. It appeared that there was not an attempt to get the balls at the nominal size that was in the update. All teams found that the capacity of their robots was less than it was at home. This caused problems for many machines, some could handle it with no problem. Just a warning about April in Florida, maybe the airconditioned stage will help.

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Posted by Joe Johnson.   [PICTURE: SAME | NEW | HELP]


Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

Posted on 3/15/2000 2:59 PM MST


In Reply to: Ball size? posted by Greg Mills on 3/15/2000 1:58 PM MST:



It is our considered opinion that the balls (I use the term loosely) were not within spec.

We never really challenged any for their size.

Mostly we just learned to live with them.

I would not count on the balls being any smaller or any rounder at the Nationals than they were at GLR or at KSC.

Joe J.

P.S. I heard some folks at FIRST talking about a BOX that they used to inflate the balls to the right size. I may have missed something, but I don't recall a box being discussed in the regulations. It was my impression that diameter was the gauge rather than the smallest square that could contain the equator of the ball.

P.P.S I very much recommend that FIRST use circumference along the equator as the measure of a good ball. To my mind it is much easier to measure and it is also more repeatable than diameter which is not really well defined on a ball with a non-circular section through its equator. Just my opinion.

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Posted by Jason Rudolph.

Student on team #168, The Flashbacks, from North Miami Beach Senior High and Velda Farms/FedEx/ETC/HPE Automation.

Posted on 3/15/2000 3:07 PM MST


In Reply to: Balls? You had BALLS? posted by Joe Johnson on 3/15/2000 2:59 PM MST:



Not only were we playing with eggs, footballs, and pieces of 'modern art', but the balls seemed to be much softer than what were at the kickoff, or in the kit. Maybe the whether in Florida did this, but it did give many teams problems, and I don't think that air conditioned tents are going to solve this. Besides, there is still going to be one field outside if I'm correct. FIRST needs to do something about this.

Jason

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Posted by Lora Knepper.

Student on team #69, HYPER (Helping Youth Pursue Engineering & Robotics), from Quincy Public Schools and The Gillette Company.

Posted on 3/15/2000 3:53 PM MST


In Reply to: Re: Balls? You had BALLS? posted by Jason Rudolph on 3/15/2000 3:07 PM MST:



:Besides, there is still going to be one field outside if I'm correct. FIRST needs to do something about this.

Yes, the main tent is still going to be exposed. But my mind is drawn back to 1998 when we had the large balls. The size on these were smaller than spec, and the consistancy was softer. That was at both the New England Regional and the National. Every year FIRST uses inflated balls, I never expect them to be on spec. It seems to be the nature of the beast.

Lora

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Posted by Brett R..

Other on team #201, Viste-Feds, from Rochester High School and Visteon Automotive Systems.

Posted on 3/16/2000 2:24 PM MST


In Reply to: Re: Balls? You had BALLS? posted by Jason Rudolph on 3/15/2000 3:07 PM MST:



No they don't. Build a robot that can cope with them. I don't know if any other teams noticed, but the black balls seem to be made of a different mix of rubber or polyethylene, whatever they make 'em out of, it's different than the yellows, and it makes for quite a bit of variations in the colors.

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Posted by Samuel Lindhorst.

Engineer on team #240, Mach Vee, from Jefferson High School and Visteon.

Posted on 3/16/2000 1:49 AM MST


In Reply to: Balls? You had BALLS? posted by Joe Johnson on 3/15/2000 2:59 PM MST:



: It is our considered opinion that the balls (I use the term loosely) were not within spec.

Undersize, mostly. I think CD5 had problems with that, and I know we did.


: P.P.S I very much recommend that FIRST use circumference along the equator as the measure of a good ball. To my mind it is much easier to measure and it is also more repeatable than diameter which is not really well defined on a ball with a non-circular section through its equator. Just my opinion.

Use both. The circumference around the seam is a more repeatable dimension, but it's easy to underinflate a ball using only one axis. Using the 'long' axis too gives a ball with a more consistant performance, we've noticed. I think FIRST thought so too, which is why they elected to use both axis. As much as we would like to see it, I doubt circumference checks will be done because they are too time consuming.

I'm pretty sure even the diameter check isn't being done consistantly, or that after it's done the ball is ever checked again unless there's a specific complaint (which we are all too busy to bother with).

Sam

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Posted by Chris.   [PICTURE: SAME | NEW | HELP]


Coach on team #308, Walled Lake Monster, from Walled Lake Schools and TRW Automotive Electronics.

Posted on 3/16/2000 5:51 AM MST


In Reply to: Ball size? posted by Greg Mills on 3/15/2000 1:58 PM MST:



:
: What was the condition of the balls at Great Lakes? It was hot at KSC and the balls were at the top of the spec. both ways.

Don't know. We never looked that closely since it doesn't matter to us.

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Posted by Andy Baker.

Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.

Posted on 3/16/2000 6:23 AM MST


In Reply to: Ball size? posted by Greg Mills on 3/15/2000 1:58 PM MST:



We'll bring our measuring hoops to the IL Regional.

We've got 12 inch, 13 inch, & 14 inch diameter metal hoops (1 each). They will be in our (team 45) pit if anyone wants to use them. Just bring 'em back when you're done.

Andy B.

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Posted by Pat Major.

Other on team #468, Explorer, from BSA/Baker.

Posted on 3/16/2000 10:08 PM MST


In Reply to: We've Got Hoops posted by Andy Baker on 3/16/2000 6:23 AM MST:



: We'll bring our measuring hoops to the IL Regional.

: We've got 12 inch, 13 inch, & 14 inch diameter metal hoops (1 each). They will be in our (team 45) pit if anyone wants to use them. Just bring 'em back when you're done.

: Andy B.

Andy,
Hope you like the Baker shirt you took off my back, Hey don't worry we got a great hat. It was nice talking with you at GLR.
Pat