2014 Game Ball Damage

[jee7s]

This is a big heads up for FRC teams in 2014.

While building a replica of one of the Robot in Three Days pickup mechanisms, our team popped our game ball. Now, I wasn't there to witness it, but I did see the aftermath. Our students were using the same wheels as the Ri3d example (AndyMark white plastic treaded wheels am-0940 or similar) and they say they were spinning them a little too fast. Based on what I saw, the edge of the treaded wheel caught the fabric and tore it, then it tore through the ball. It wasn't a huge hole, maybe 3/4" or so. But any hole deflates the ball, right?

Takeaway message: THE 2014 GAME BALLS ARE MORE FRAGILE THAN THEY SEEM. Our students weren't doing anything to the ball that we wouldn't have expected to see in game play, other than running the pickup a little too fast. So, while testing, please be mindful of this. Also of note: these balls are not nearly as durable as the type used in 2008. The 2008 ball was a rather durable solid surface type. This 2014 ball is a very foamy type of material, which seems to be more susceptible to tearing. I checked the manual, and both are made by Sportogo. But, I recall quite vividly that the 2008 ball was a more durable PVC.

This is a scenario that I can certainly see playing out at events. We are going to see untested pickup mechanisms using similar wheels that will be run too fast. So, teams, PLEASE prudently test your mechanisms so events don't go through their supply of game balls on practice day.

[Sparkyshires]

Ouch, definitely will keep that in mind. We weren't sure how fragile they were, so we've been playing on the safe side. What wheel type were you using?

EDIT: oops, nevermind, second paragraph. Shows what reading can tell you!

[jee7s]

The wheel was the 6" andy mark molded rubber wheel am-0940.

https://www.andymark.com/product-p/am-0940.htm

We had a 2012 version with the non-white tread, but per the AM page, they are the same wheel save for the pigment.

It appers to be the same wheel presented in the Ri3d pickup here:

http://www.youtube.com/watch?v=4WZ1t...c4-overview-vl

To be clear, I'm not saying the design is bad. I'm saying that if you run the wheel too quickly, you may run into damage.

[Hallry]

Originally Posted by jee7s

While building a replica of one of the Robot in Three Days pickup mechanisms, our team popped our game ball. Now, I wasn't there to witness it, but I did see the aftermath. Our students were using the same wheels as the Ri3d example (AndyMark white plastic treaded wheels am-0940 or similar) and they say they were spinning them a little too fast. Based on what I saw, the edge of the treaded wheel caught the fabric and tore it, then it tore through the ball. It wasn't a huge hole, maybe 3/4" or so. But any hole deflates the ball, right?.

This happened to us yesterday too, in a very similar situation . Off to the nearby hardware shop to pickup a bicycle wheel repair kit while waiting for our order of additional balls to arrive!

[coalhot]

I have a feeling that ball damage is why many 2008 teams used rollers (see: Bomb Squad)

As long as you don't tear through the fabric, you should be fine. At least that's what it seems...

[JohnSchneider]

I feel like non-smooth wheels like that would be more apt to tear the ball up, because of the constant change in surface and "snagging" of the balls fabric (magnified by a faster RPM).

[Dan Richardson]

We used the 6" white tread wheels from AM (previous kit wheels) on the outside and 4" kit wheels in the center. We compressed the ball pretty heavily (5-6"?) in testing tho settled in at much less 2-4". We fortunately never popped the ball and we abused it. During testing we approached the ball from many angles and optimized the compression on the ball via the Modulox channel.

As an idea for speed we were using the PG-27 with a 1:1 chain reduction. It was driven at roughly full power in an on/off state. I don't believe there was any coded ramp function.

It sounds like we may have been lucky, but the ball held up well in our testing. The wheels may also have some sharper edges leftover from manufacturing. It may be worth while to radius the edge via sand paper or a file. Also do everything you can to make sure no sharp metal edges are in the vacinity of the ball.

[Tom Line]

Ball damage was a problem in 2008. Field personnel came around to the pits of robots who had been observed damaging balls with pickups or other mechanisms and warned the teams that they would not be allowed to return to the field until an inspector had verified that they corrected the issue that was causing the damage. In many cases that equated to slowing down the roller on their intake.

[discobrisco]

We have also had ball damage, thanks to USPS have no backups, so we have made beautiful repairs with duct tape. https://drive.google.com/file/d/0Bw9...it?usp=sharing

[JeremyLansing]

We had a similar issue where the ball was punctured during our shooter test. For anyone else who has a popped ball and is waiting for AndyMark to get more in stock, we put a normal exercise ball in the cover as a temporary measure. Its 2.6lbs and is 25" in diameter. It has more give than the standard game piece, but has worked pretty well as a temporary stand in so far. Given how easily our ball burst, I wouldn't be surprised to see a graveyard of popped balls at the competitions.

[Hallry]

Originally Posted by JeremyLansing

For anyone else who has a popped ball and is waiting for AndyMark to get more in stock, we put a normal exercise ball in the cover as a temporary measure.

Instead of waiting for AndyMark to get them from Sportogo and then buy them from AndyMark, why not just buy them straight from Sportogo? They don't have any with the official FIRST logo on them, but you can get a same size/weight ball with a tennis ball/magic 8 ball/etc. cover instead, and they are cheaper that way. Or, if you already ordered some extra balls from AndyMark and those popped, you can keep the cover and just order new bladders from Sportogo.

[DonRotolo]

Originally Posted by JeremyLansing

I wouldn't be surprised to see a graveyard of popped balls at the competitions.

And to go with each popped ball, G10 will assess a FOUL. Do it repeatedly, and you may need to modify the robot to ensure it cannot happen again.

The point is: If your robot uses a mechanism that can pop a ball, best think of a redesign now, instead of at the competition...

[GaryVoshol]

Originally Posted by DonRotolo

And to go with each popped ball, G10 will assess a FOUL. Do it repeatedly, and you may need to modify the robot to ensure it cannot happen again.

The point is: If your robot uses a mechanism that can pop a ball, best think of a redesign now, instead of at the sompetition...

I was going to say that G10 excluded the BALLS, then I read the Blue Box. Not the best way to write a rule, to specifically exempt something and then reinstate the prohibition.

So like Don says, don't pop the balls.

[waddell]

We just punctured ours. I hate it when that happens.

Has anyone had good luck patching their ball?
What materials were used (patch & adhesive)?

Thanks,
Waddell

[cadandcookies]

Originally Posted by Hallry

Instead of waiting for AndyMark to get them from Sportogo and then buy them from AndyMark, why not just buy them straight from Sportogo? They don't have any with the official FIRST logo on them, but you can get a same size/weight ball with a tennis ball/magic 8 ball/etc. cover instead, and they are cheaper that way. Or, if you already ordered some extra balls from AndyMark and those popped, you can keep the cover and just order new bladders from Sportogo.

After looking at that site, I really want to see one of those 8' or larger balls as a game piece. Not really sure how scoring would work, but I'd imagine the robots would be tanks.