[FTC]: Picking up balls

[h3x]

Originally Posted by Joyride_67_1902

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

- Andrew

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

[Andrew Remmers]

Originally Posted by h3x

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

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

- Andrew

[alphadog0309]

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!

[wilsonmw04]

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.

[PhilBot]

Originally Posted by wilsonmw04

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.

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.

[wilsonmw04]

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

[Andrew Remmers]

Originally Posted by wilsonmw04

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

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

- Andrew

[wilsonmw04]

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

[h3x]

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.

[kz2zx]

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.

[h3x]

Originally Posted by kz2zx

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.

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.

[PAR_WIG1350]

Originally Posted by h3x

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.

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.