Does anyone have a good idea or tips for an effective way to pull in a soccer ball, maintain possession of it by continually holding it, while still being able to drive forwards, reverse, and turn? So far the only idea that comes to mind is a vacuum. Your thoughts? Thanks. 
Oh, thanks. I guess my thread was a waste then
As long as you got the help you were looking for, then it was not a waste at all.
I watched the ball magnet video and it seems like there’s a cylindrical wheel thats spinning in the direction of the robot to pull in the ball and the wood is only there so it does not go into the robot, like the balls would have for last years game. But i think there’s a way i could implement this somehow and possibly also use a vacuum to help maintain possession. So this was a big help 
Try it with the roller and you might decide you don’t need vacuum. But you’ll have to try it to know, won’t you?
good point, i’ll try to put something together tomorrow to test it out.
The limiting factor with our robots is the three inch rule. In our test the ball stayed with the robot going left and going right and even backwards but when the robot moved forward and suddenly stopped the ball popped right out.
Unless we can overcome this limitation the magnet may not work as well as we hope. The next step for us will be trying different sticky materials to coat the roller with . Any good suggestions?
Yeah, I was planning on trying out a vacuum suction deal, but after seeing the power of the roller, I think that is all we will need. Looks like tomorrow I’ll be trying out the roller on last year’s bot wit the soccer balls. Too bad we just pulled the cRio out!
maybe have something thats gonna have a lot of friction with the ball like sandpaper so that even if you stop it won’t move away from the bot, cause the material will be too rough.
It will be interesting to see how changing the height of the roller and ingress of the ball affects it. I can see how it could be a problem if we have the ball not in so far, so we’ll work on prototyping a more legal version real soon.
Thanks for the input Sam.
btw the roller in ours is ABS pipe covered with spray rubber, which is a product designed for coating tool handles and such.
How about the Sticky Pad? It is a tacky material to help hold cell phones, PDAs, etc. on a dash.
Another idea is the tacky shelf liner. It come in large rolls, so you should be able to attach it to a roller.
Good luck. I look forward to seeing your results.
I was thinking of using spray rubber.
We have lots of experience with drawer liner, but it just falls apart to easily. Not a big problem last year but not real good for the soccer balls. The other thing to worry about is the inflated state and the surface texture of the ball can cause problems.
I’m thinking about a spring loaded roller or something.
We used the same coating on our grippers to handle game pieces in 2007. Tackiness rules!
Imagine a large pair of pliers. Take the handles, coated with friction tape or gripper tape, and point them away from you. With the handles opened as wide as they go, the mechanism could satisfy the perimeter rules. Considering the 3 inch penetration rule, when you get to a soccer ball and close the plier-inspired device, the “handles” may in fact extend up to the bumper perimeter, but two seconds may be enough time to grab the ball, reposition, and pass it up field.
Thoughts?
so i tried out the shop vac idea today and it had very little suction to do anything. We’re definitely considering the roller idea with either that spray on rubber, that tacky material, or the sticky pads. I don’t know yet we have to test it out and look at the results. I’m going to try and design a prototype on inventor and test the limits of the three inch rule while still being able to keep possession of the ball.
I think your idea could work, but i’m not sure how well of control you’ll be able to have. But is two seconds really enough, you can’t really do that much with such little time and have to react very quickly and efficiently to prevent getting a penalty. Do you think its possible for you to close the plier-inspired device and still satisfy the 3 inch rule. We’re planning on over compensating the design so that it is physically impossible to break this rule. But still sounds like an interesting idea. Let me know how the friction with the soccer ball is after you try out your idea, cause the ball slipping is going to be an issue if you’re trying to maintain control and possession.
Any ideas on a two stage vacuum system. High volume until the ball catches and then a high pressure to hold it. Moving a high volume of air for any lenght of time will take a toll on the batteries.
We successfully finished our prototype of our intake roller design and it is a marvelous thing to watch. Not being immodest, I am just amazed it works as well as it does. We literally had a student skid a ball toward our roller as fast as he could and it stuck with virtually no noticable elastic collision.
We went with a 1 inch PVC pipe coated on both Brecco-flex and tool-handle-rubberized-coating and both worked equally well. Since the coating is significantly less weight, we are definitely going that route.
We also tested our scissor/plier handle idea as was mentioned in the thread earlier and it works extremely well, but the final mechanism we would have to design gets a little complex when trying to also avoid conflicts with a kicking mechanism.
We finally came up with a concept that can grab the ball on any place of the roller, bring it to the center, and hold the ball “perfectly” in the center of the robot even when turning. It can be done and maybe we will give up a few hints in an upcoming video post.
BTW: I thought the task of gaining control of a ball and actually moving it around the field like the play thing it is was near impossible in 3" until we finished today. Keep trying a bunch of different things and you’ll eventually get it.
Thanks for the report!