Soccer Ball Sold Out

[Greg Needel]

So, I am with you all on this one and it would have been nice to get one in the kit. That being said there is no reason for all the bashing going on in this thread. Yes, things could have been handled differently. Yes, There is the potential that your mechanism will not function the same with the "real" balls vs walmart ones. The issue here is that people are brewing on it, which solves nothing.

I suggest you all be Proactive about the situation, figure out what could make a ball different and try your best to prepare. There is a lesson in this that I feel people are missing because they are blinded by their emotions. Sometimes stuff happens that is beyond your control and you can and should rise to the challenge to overcome the problem.

I hope that when people look back on their build season they won't blame the fact that they couldn't buy the exact ball on the reason their robot was not as successful this year, and will attribute your season's successes to the process and challenges your team had to overcome to finish the year. Don't be distracted by this, it will only put you behind in your design.

Now go design your robot and stop complaining.


Also if anyone who was able to buy a ball wants to do some leg work for other teams, take the real ball to $@#$@#$@#$@#$@# sporting goods and see what is close. While I am not a soccer player I find it hard to believe that there is a huge difference in such a low cost item. (if we were talking about 300 world cup balls I might buy into it).

[Jon236]

Originally Posted by Greg Needel

Now go design your robot and stop complaining.

Greg,

Amen to that. I called Eyal and told him the problem we were having here getting soccer balls; he couldn't stop laughing. He said soccer balls are 30 NIS (~$8) and readily available in Israel. I suggested that maybe his teams could supply the balls to FIRST as a fundraiser!

[David Brinza]

I just spoke with a DTI Sports sales rep. Upon request, they will substitute the HS500 for the HS300 for immediate shipment. They are expecting a new shipment of HS300 balls by Jan 25, for those who are willing/able to wait.

I don't think acquiring the game piece should be part of the challenge of FRC. Apparently, I'm just not thinking the right way.

"Fool me once...shame on you. Fool me twice..shame on me." But, fool me everytime? I think Einstein had an answer for that!

[Greg McKaskle]

For teams intending to use vision to locate the soccer ball, there are a number of things that may be useful to consider.

1. The soccer ball chosen doesn't have a saturated color that is easy to mask. Robo Cup traditionally uses orange elements to make things easy, but they are starting to move away from that to up the challenge.

2. 3D shapes illuminated with directional lighting produce a huge variation in the shade of the color. Almost half of the ball will be in its own shadow.

3. Bright lights cause specular reflections -- glare. Matte objects have larger blurrier reflections which are a blend of the surface and light color, and shiny objects have smaller, sharper and brighter reflections which tend more towards the light color. In other words, no matter what the color, the field lighting and shop lighting will cause many holes in the image of the ball.

On the positive side, you might consider the background behind the soccer ball. Think of the soccer ball, shadows, etc. punching a hole in the carpet. Especially for autonomous, this seems like it might be a viable approach for locating the ball using the camera.

Greg McKaskle

[MrForbes]

Also the balls are very glossy, very reflective. I expect you'll have a lot of trouble with reflections from the lights in the arena.

[dtengineering]

I'm glad to read that more HS300 balls are on their way. We just had a couple of HS500 balls delivered yesterday and they are, as Jim says, very glossy and their surface finish definitely has a lower coefficient of friction on carpet than the old, beat up ball we were originally testing with.

That said, I'm not sure how long the pristine surface finish will last... probably quite a while, so long as we don't subject the balls to the vicious high speed ball grinder that our first prototype "backspin roller" turned out to be. Who knew AM wheels could melt soccer balls?

A lower speed, higher friction approach appears to work better, and we've had good success using the intake roller off last year's robot with both the new and older balls (about 2" diameter Al tube with McMaster round belting on it, driven by FP motors on a 64:1 reduction, as I recall)

But several soccer players have commented on how glossy the balls are... I'm glad we now have a standard to base our designs on... we'll inflate one ball to 27" circumference and another to 29" so we can test kicking and control at both inflation extremes.

Jason

[Greg Needel]

Originally Posted by dtengineering

I'm glad to read that more HS300 balls are on their way. We just had a couple of HS500 balls delivered yesterday and they are, as Jim says, very glossy and their surface finish definitely has a lower coefficient of friction on carpet than the old, beat up ball we were originally testing with.

That said, I'm not sure how long the pristine surface finish will last... probably quite a while, so long as we don't subject the balls to the vicious high speed ball grinder that our first prototype "backspin roller" turned out to be. Who knew AM wheels could melt soccer balls?

A lower speed, higher friction approach appears to work better, and we've had good success using the intake roller off last year's robot with both the new and older balls (about 2" diameter Al tube with McMaster round belting on it, driven by FP motors on a 64:1 reduction, as I recall)

But several soccer players have commented on how glossy the balls are... I'm glad we now have a standard to base our designs on... we'll inflate one ball to 27" circumference and another to 29" so we can test kicking and control at both inflation extremes.

Jason

Would it be possible for anyone to compare these balls to the wilson hex soccer ball available at walmart? I have already seen this ball as the most common one in people's prototyping pictures and videos.

[MrForbes]

I'd like to compare them, but the Wilson ball is in the fab shop, and the spec ball is in the meeting room! I'll see if I can manage to get them together for a comparison. I also need to remember to get a pressure gage....

[Chris is me]

Personally, I'd rather vision track the goals than the ball. You place the ball where you want to and drive until an IR or ultrasonic sensor on your robot indicates it is properly possessed, then you aim at the goal. Though since there's no particular reason your aim should be different every round, the camera isn't too important.

[m3ch4num470r]

After the DC Regional, team 449 found an issue with not having access to an official ball.

We use a vacuum attachment for grabbing balls. It was working incredibly well with our Size 5 ball back in our school, so we figured it would work well at competition. We adjusted it at competition using our ball, then went out to compete. The vacuum didn't pick up a single ball. Finally, on day two, we went out to the practice field and put a ball against our vacuum opening. Lo and behold, the official soccer ball is larger than ours!

If your robot needs something in precise contact with the ball, please learn from our mistake and remember that the official balls could be a different size than yours, even if you were using a size 5 ball. Take the time to go out to the practice field and adjust your mechanism properly for the official ball on the official field. If your mechanism isn't adjustable, take some time to think about how you might make it adjustable quickly at competition. We were lucky enough to have an 80/20 mount, but I know that a lot of teams are more refined and use welded aluminum.

We also noticed that the ball was bouncier than ours, so we were kicking a little further (no complaints there). Obviously, your mileage will vary based on which ball you used.