Re: Mechanism to Possess Soccer Balls
 

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.

Re: Mechanism to Possess Soccer Balls
 

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.

Re: Mechanism to Possess Soccer Balls
 

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.

Re: Mechanism to Possess Soccer Balls
 

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.

Re: Mechanism to Possess Soccer Balls
 

Thanks for the report!

Re: Mechanism to Possess Soccer Balls
 

Yes, thanks for the report!

Quick question.... was this test done on carpet?

Re: Mechanism to Possess Soccer Balls
 

Absolutely. It was done on carpet. Thanks for catching my omission.

Re: Mechanism to Possess Soccer Balls
 

Just be careful ofYou mean like Dave's Loud Hawaiian Shirts tackiness??:rolleyes:

Re: Mechanism to Possess Soccer Balls
 

we've been trying similar things with rollers on carpet but the balls grip and go under. With new soccer balls they tend to grip the carpet when pushed down on and so don't spin well. On smooth floor or on older balls it works perfectly. Any suggestions?

Re: Mechanism to Possess Soccer Balls
 

I'm having similar problems with the ball not sliding on the carpet and wanting to pull under the roller. I tried some small rollers behind the ball, below the center line with some success, but the positioning is really touchy. The slight out-of-round of the ball is enough to stop the spinning. Next, I think I'll try letting the roller move up and down and see if that helps.

Re: Mechanism to Possess Soccer Balls
 

The friction and speed of the roller seem to make a big difference, and slower may be better. The roller doesn't have to be real large either.

Re: Mechanism to Possess Soccer Balls
 

In our testing we found that a roller coating that could not easily compress helped reduce the tendency of the ball to want to pull under the roller.

I'll try to get our video of a prototype using drawer liner material on a PVC roller up somewhere to post here. The carpet we were able to scrounge up on short notice was berber and very different from the competition carpet, but we still found the test successful enough to move forward with the idea.

EDIT: Here's the video

Re: Mechanism to Possess Soccer Balls
 

Kevin, thanks for the video. I think the big difference is that I had my roller mounted higher up on the ball. I'll try lowering it an see what happens. Otherwise, my setup looks pretty similar. The ball I was using doesn't have a shiny surface so it may grip the carpet more. I'll try another ball too.

Re: Mechanism to Possess Soccer Balls
 

We got one of the spec balls, not the right color, but it is a HS300 it's very glossy.

Re: Mechanism to Possess Soccer Balls
 

I just tried a glossy ball, not the spec ball, and probably not quite as glossy but not matte either. Much better. I should have read the "out of stock" thread first. The height of the roller is much less touchy with the slick ball too. Maybe this will be the one advantage of being at a first-week regional, the balls won't be scuffed up yet.