[FTC]: Picking up balls
 

We are struggling to find an effective and easy way to pick up balls, preferably using parts we have.

We are planning on using a scoop type thing, but I don't think this will work well. I would rather it be a system where we just drive are robot into the balls and they are automatically lifted.

Any ideas? Thanks.

Re: [FTC]: Picking up balls
 

Look at FRC robot designs from the 2006 aim high season in which they had to pick up poof balls. I saw a lot of this particular design in the FTC Hot Shot season but I don't have ready access to pictures of those FTC robots. So look around for hot shot wiffle ball collectors for inspiration.

Re: [FTC]: Picking up balls
 

Find a copy of FIRST Robots: Aim High: Behind the Design. It showcased 30 designs in great detail from the Aim High game.

Amazon

Re: [FTC]: Picking up balls
 

Thanks, that's not a bad idea. I don't think I want to buy a book though, at least not yet.

Any others?

Re: [FTC]: Picking up balls
 

Think about how sports pick up mass amounts of balls. Just like in FRC, the people who play sports must have lots of practice to succeed, thus they use many balls at a time to make practice more efficient.

Find game footage from 1992 FRC on youtube. It exists, though that mechanism may be a bit more complicated than what a couple of sports use.

Re: [FTC]: Picking up balls
 

Interesting, so like a big wheel that lets balls get caught in it? Maybe, but that could be too big. If the balls need to get 16 inches off the ground, the wheel would take up almost all of the space for our robot. But, I suppose it could work well. I am going to look into this more.

Any other ideas? I can never have too many :p

Re: [FTC]: Picking up balls
 

My team looked at several designs and prototyped 4 of them. A few examples:

http://www.flickr.com/photos/wilsonmw04/6269327145/
http://www.flickr.com/photos/wilsonmw04/6269323299/

And here is what my team feels is the best way to collect balls:

http://www.flickr.com/photos/wilsonmw04/6269329547/

Re: [FTC]: Picking up balls
 

Nice, great post. How do you plan on lifting the balls up? Maybe you could stack a few of those on top of each other, then put a sheet behind them.

Re: [FTC]: Picking up balls
 

Kinda like this one

http://www.youtube.com/watch?v=GoQMytvmFz4

I know its a different game, but its the same concept.

Enjoy the video :D

- Andrew

Re: [FTC]: Picking up balls
 

Thanks, nice concept. What kind of issues did you run into? Do you think this will work for the smaller and heavier racquetballs?

Re: [FTC]: Picking up balls
 

We didn't have to many issues with this one, we actually made it bigger for the final one and it worked a lot better. We are doing something a bit different this season :D

- Andrew

Re: [FTC]: Picking up balls
 

we currently have a system that works pretty well for us :) check out our video of it working here
(don't mind the music... we were bored and couldn't think of anything else)

but if you do want to see some more detail of it look at our CAD renders on our facebook page here (hopefully that works for you...)

we basically went through our previous designs from hot shot and looked at what worked and what more often than not didnt work. we determined that picking balls up by pushing them from the back required too large of a radius and required us getting too low to the ground which led to us getting jammed up so we focused on finding a new method which didnt require us to have to get so low and thus our current design...

im sure you will find a mechanism that works for you!

Re: [FTC]: Picking up balls
 

For all those thinking about large intakes, please take a look at rule SG-15...
We had to redo our entire intake to be in compliance.

Re: [FTC]: Picking up balls
 

Yes, and if you need a bit of a laugh, read the Offical Q&A's regarding inspections, which will check to ensure that you can't hold more than 15 Balls.

There are some realllllly whiney questions :)

Phil.

Re: [FTC]: Picking up balls
 

This is what we made a few weeks ago.
http://www.flickr.com/photos/wilsonmw04/6384924289/
It works quite well, but is completely illegal.

Re: [FTC]: Picking up balls
 

Not sure why its "completely illegal" in fact it doesn't look like it would ever hold 15 balls anyway.

- Andrew

Re: [FTC]: Picking up balls
 

It fits 21, therefore illegal. We got it fixed though!

Re: [FTC]: Picking up balls
 

These are all good ideas for picking up many balls.

Does anyone have any very simple ideas for how to pick up just one ball at a time, or much less? We were thinking a smaller conveyor belt, but there has to be a simpler way. From what I've seen, claws or shovels are too complicated or take up too many resources.

Re: [FTC]: Picking up balls
 

We used 2-1/2" PVC pipe with a chain and paddle system to elevate balls and make them turn a 90' elbow at the top. We used a second similar system to index/advance non-magnet balls after we sorted them, to move them to our crate-feeding mechanism.

1 servo for each. Not inexpensive, because the sprockets are either expensive to buy from Tetrix, or expensive to mill (very high failure rate in production), and requires a lot of robot structure to take up slack in chain. Also, engineering the mounting system for the paddles to the chain is a pain and requires grinding sprockets, plus cutting relief holes for the paddles in the pipe. Took us a while, and I think we'll go for open transport systems next year if one's involved.

Re: [FTC]: Picking up balls
 

Nice, but obviously very complicated.

I keep thinking there has to be a simpler way to elevate balls, but I'm not sure if there actually is one.

Re: [FTC]: Picking up balls
 

The biggest issue with claws and shovels is not their complexity, but rather how forgiving they are. With a conveyor, you drive over it and you pick it up. with a claw, you have to get the claw in exactly the right position. The result will likely give the drivers a migraine from the frustration of trying to coordinate arm and robot position while other robots are moving around. The best claws preform pickup operations directly in front of the robot like a conveyor belt, but with round objects there is the additional complication that if the driver hesitates upon contact with the ball, it will roll away from the claw. Luckily, The ease of use of the conveyor and the selective collection of the claw can be found in the roller/conveyor claw.

that being said, the only thing less complex than a typical conveyor is the degenerate case, a big wheel. It has only one moving part, but this is paid for by its large size.