I was looking through the manual, and found the instructions on how to blow up the ball. I also noticed that they showed pictures of what the ball SHOULD look like when it is under-filled, correctly filled, or over-filled. I dont like this because the amount of air in the ball could make a huge difference, and I dont think that it should be determined by “I think this looks right”. Has anyone seen if they say how much air to put in it instead of just pictures? I really hope that they do, and that I just missed it, or that they are going to come out with something in an update.
Joey
From last year’s experience with the inflatable tubes, I strongly suggest you make you robot so it will work with underinflated, correctly inflated, and overinflated track balls.
I completely agree. Last year for tubes however at the competitions they had gauges to fill the tubes so they had exactly the same fill. I dont remember if they told teams ahead of time how full they would be though. I know the balls may deflate through out the matches, but I feel that all balls should start with the same fill, and if they get so low that you can notice a difference, they should be refilled.
Joey
Last year, it was written in the manual what approximate inflation was, but even at regionals, tubes were under and over inflated. When you’re in a rush to reset and you need tubes (or balls, or anything else that’s inflated), you don’t always have the time to check for perfection.
Tubes that started filled and had small holes/leaks, were underinflated by the time many teams went to pick them up anyway. Expect a few completely deflated balls too, with some very large holes.
Balls/tubes actually are refilled during a competition. Usually the day before everything is inflated, and then as things get really underinflated they’re replaced with new game objects, refilled, and used again later.
Well, you can always find the circumference of the ball is supposed to be and then physically measure the distance around the ball, and make sure they match.
oooooooo… good idea, didn’t think of that.
even though you want to get the trackballs at the correct size, there will be some variation at competition. when they are that big, the differences are bigger than, say if they were, 12 inches. 10% bigger on a trackball is four inches, and on a 12 inch ball would only be 1.2 inches. So leave a margin for variables.
it took me forever to pum the dang thing up yesterday. my compressor broke so i did it with a foot pump… my legs are so sore… who knew a ball needed that much air:confused:
ANyone know where to get more trackballs???
No. That seems to be the “million dollar question” this year so far.
FIRST has not released an official source to get spares and/or replacements as of yet…
Hopefully they will soon though with the staggering amount of requests we’ve seen here.
The balls look very similar to an ‘Omnikin Ball’ that we have in our gymnasium – complete with poly-canvas cover. Typically, the balls are 48" in diameter, but I’ve found some 40" Omnikin balls on the net.
http://www.sportsdirectsource.com/products/359
…unfortunately, neither one gives the precise weight.
Patrick
Let’s see now, we got our kit on. . . Saturday. Our team met 3 times or so since then, it’s now thursday so it hasn’t even been a week. AND we have popped our trackball. We are very efficient if I do say so myself. 
We’re doing our best to patch it and it’s turning out well. By the way we popped it tuesday, yeah thats right 3 days.
As a former gauge engineer… why don’t they come up with a simple set of GO/NO GO gauges? The GO would tell you if the trackball is too big in diameter and the NO GO would tell you if the trackball is too small in diameter. By passing through the GO, you would know the trackball was not too big and by not passing through the NO GO, you would know that the trackball was not too small. The gauges could be as simple as two pieces of lexan, if you wanted a 40" diameter trackball, one would have a 41" hole (GO, not larger than 41") and one would have a 39" hole (NO GO, not smaller than 39").
If you are more concerned with bounce/air pressure, a simple pressure gauge would work.
As in previous years, the design of the robot should be robust enough to account for variances in trackball size and weight. Competitions are too dynamic to spend time measuring and adjusting trackballs between every match. Precision has its place in robotics, but interaction with real world environments is not it!
Be assured that every match will start out with big giant red and blue trackballs and they will be ABOUT 40" in diameter and ABOUT 10 pounds. They may even be approximately spherical!
Keep in mind, FIRST competitions run on a very tight schedule.
FRC matches are usually about 6 minutes from start to start. 6 minutes for reset, unloading and reloading robots, and making sure the scoring system is ready to go. And that 6 minutes goes by VERY quickly. There just isn’t enough TIME to check to make sure everything is perfect.
Generally, the folks on field reset are told to keep an eye out for anything that looks seriously deflated, or anything with a hole in it. But expect there to be some that are only inflated to about 36" to still be on the field.
There was one year that we had a box to make sure balls were the right size, but that being said, it was only for initial inflation.
And most regionals didn’t use it. It’s just time consuming, that’s all there is to it.
Quote: "Keep in mind, FIRST competitions run on a very tight schedule.
FRC matches are usually about 6 minutes from start to start. 6 minutes for reset, unloading and reloading robots, and making sure the scoring system is ready to go. And that 6 minutes goes by VERY quickly. There just isn’t enough TIME to check to make sure everything is perfect."
That is very true. Even on Einstein last year, I, as human player, had to go through all of the tubes on our side to make sure that they were good and ask for the bad ones to be replaced. I do think it will be much better this year, however, since there are a total of 4 Trackballs as opposed to the dozens of Ringers last year.
One variable in the Trackball inflation is temperature. Our Trackball changed from being super tightly inflated to being quite loose within an hour or so, due to being removed from a hot trailer. I assume that the temperature at competition will be constant enough to limit that effect, but it is something to think about.
Hope for the best, design for the worst - that’s your best bet.