Ball dimensional variability

[mman1506]

The bladders are actually supposed to be 25 inches in diameter. That could explain why they tend to be on the large side. http://www.sportogo.com/2565cmbladder.aspx

[qzrrbz]

gotta think that inflation pressure is going to have some effect here, too.

how uniform will *that* be at comps?

[CalTran]

Originally Posted by qzrrbz

gotta think that inflation pressure is going to have some effect here, too.

how uniform will *that* be at comps?

At comp, they might do the same as what they did in 2011 and have an inflation box that they use that is roughly the volume the ball is supposed to be.

[wilsonmw04]

Originally Posted by CalTran

At comp, they might do the same as what they did in 2011 and have an inflation box that they use that is roughly the volume the ball is supposed to be.

psst...
http://www.youtube.com/watch?v=Azc8AKzgEwE

[JamesCH95]

Originally Posted by CalTran

At comp, they might do the same as what they did in 2011 and have an inflation box that they use that is roughly the volume the ball is supposed to be.

If you noticed during 2011 some (many?) field workers just pumped up the tubes as hard as they could, shoved the sizing gauge over the tube and went "hey, it fits!" and put them out on the field grossly over-sized. In 2007 the exact opposite was true, tubes were generally grossly under-inflated.

No matter what the regulation is we better count on someone who does not appreciate the implications of their seemingly trivial volunteer job at an event. Balls could be very over-inflated, under-inflated, or both. Plan accordingly.

[Carol]

Originally Posted by mman1506

The bladders are actually supposed to be 25 inches in diameter. That could explain why they tend to be on the large side. http://www.sportogo.com/2565cmbladder.aspx

We called Sportogo and confirmed that this is the piece used in the official FIRST balls. Because we already popped ours and needed a replacement!

[TerryS]

We followed this inflation guide:
http://www.usfirst.org/sites/default...ance_Guide.pdf

We measured the circumference. Independent measurements were made by three students. The average diameter of eight measurements was 24.7 inches.

We got burned by larger tournament tubes than we had designed and practiced with in 2011 so we'll make sure that we take ball diameter variance into account this year.

[AdamHeard]

Originally Posted by TerryS

We followed this inflation guide:
http://www.usfirst.org/sites/default...ance_Guide.pdf

We measured the circumference. Independent measurements were made by three students. The average diameter of eight measurements was 24.7 inches.

We got burned by larger tournament tubes than we had designed and practiced with in 2011 so we'll make sure that we take ball diameter variance into account this year.

That guide is junk, it essentially is a spec based on feelings and opinion and not numbers.

[Jared Russell]

Originally Posted by AdamHeard

That guide is junk, it essentially is a spec based on feelings and opinion and not numbers.

Essentially, "Inflate the balls until they are properly inflated."

[Alan Anderson]

Originally Posted by Jared341

Essentially, "Inflate the balls until they are properly inflated."

It's not quite as tautological as you make it sound. Using the zipper as a tightness gauge makes the subjective interpretation of "properly inflated" a narrower range of possibilities than it might otherwise be.

[Joe Ross]

Originally Posted by AdamHeard

That guide is junk, it essentially is a spec based on feelings and opinion and not numbers.

I thought it was fine. It says to design for several inches of variability.

[waialua359]

I would assume that ball size variability would affect ball intake designs the most.
Take it out of the equation.

[waialua359]

Originally Posted by Jared341

Essentially, "Inflate the balls until they are properly inflated."

Did I just see your username correctly? DaisyPoof? Team 254? haha...

[AdamHeard]

Originally Posted by waialua359

Did I just see your username correctly? DaisyPoof? Team 254? haha...

DaisyPoof sounds like what EJ would name the robot if the rest of the team would let him.

[DampRobot]

Originally Posted by AdamHeard

DaisyPoof sounds like what EJ would name the robot if the rest of the team would let him.

Who started the Decepticon thing then?