Ball size?

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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