Ball Launchers? Ideas?

[akoscielski3]

Originally Posted by Tubatroopa

I was actually thinking of a similar system to this. There is no reload time on the shooter so shots can be fired quite quickly.

Careful about saying that there is no reload time. In 2006 our shooter would have to get back up to speed after shooting only a couple balls. You lose a lot of energy when you shoot a ball.

[nighterfighter]

Originally Posted by akoscielski3

Careful about saying that there is no reload time. In 2006 our shooter would have to get back up to speed after shooting only a couple balls. You lose a lot of energy when you shoot a ball.

This is true, but at the most you are only going to be shooting 3 balls at a time.

Unless you have a really well coordinated alliance partner to line them infront of you, then push them into your intake as you shoot...

[the man]

What powered your shooter a CIM?

[Apeace]

Our team was starting to think about a pnuematic piston that shot-puts the ball through a barrel at the target.

Any suggestions?

[Sean Raia]

I would stray away from that idea. Pneumatics (in my experience) are much better for power than for speed. Maybe use your pneumatics to load a spring?

[the man]

Use smaller diameter cylinders they travel faster. We used them in breakaway with success. The important part was speed not necessarily mass behind the strike. KE = 1/2MV^2 I guess.

[theprgramerdude]

Originally Posted by Sean Raia

I would stray away from that idea. Pneumatics (in my experience) are much better for power than for speed. Maybe use your pneumatics to load a spring?

Power is speed. And pneumatics do not have power, they have huge amounts of force, at the tradeoff of speed. Power = F x V, don't lose the value of a scientific term by colloquially equating it with something entirely different.

[Mike Norton]

This is what we had http://www.chiefdelphi.com/media/photos/23042

What we learn is back spin is very useful to keeping the ball going long distance. Flywheel needs to be heavy. This insures very little speed loss when shooting. We had a pneumatics ball stepper. This made sure the next ball did not drop until the wheel had enough time to be at the right speed. We would shoot 9 balls in 7 second with 80 % score rate. This year is much different you have to arc the ball it is not a straight shot.

[MrForbes]

Team 25 had a pretty nifty shooter in 2006.

I seem to recall that teams that shot the ball with a single wheel that gave it a lot of backspin, did really well.

Of course the backboard messes up that idea a little bit, you have to aim for the sweet spot, a certain height above the basket.

[PayneTrain]

Originally Posted by squirrel

Team 25 had a pretty nifty shooter in 2006.

I seem to recall that teams that shot the ball with a single wheel that gave it a lot of backspin, did really well.

Of course the backboard messes up that idea a little bit, you have to aim for the sweet spot, a certain height above the basket.

I hope teams, when designing, think of how humans throw a basketball. They don't launch it at the square of the backboard, they try to arc their shot.

Think of how your rotational velocity of your pitchers, pitch of the launcher, and distance from the hoop go into arcing the ball instead of launching it.

[MrForbes]

Originally Posted by PayneTrain

I hope teams, when designing, think of how humans throw a basketball. They don't launch it at the square of the backboard, they try to arc their shot.

Think of how your rotational velocity of your pitchers, pitch of the launcher, and distance from the hoop go into arcing the ball instead of launching it.

I think that using the human method is fine for humans, but since the robot isn't human, teams might need to play around with different methods and see what can be done successfully with the fewest degrees of freedom. In 2006, like I said, teams that used a single wheel shooter that gave the ball a lot of backspin were successful. Think about how it works, and what's required to do it.

edit: also look at the teams that were successful in 2009, although the number of balls was different, there were a lot of teams that scored consistently by getting right next to the target and dumping the balls in

[Koko Ed]

Originally Posted by squirrel

I think that using the human method is fine for humans, but since the robot isn't human, teams might need to play around with different methods and see what can be done successfully with the fewest degrees of freedom. In 2006, like I said, teams that used a single wheel shooter that gave the ball a lot of backspin were successful. Think about how it works, and what's required to do it.

The target in 2006 was like throwing a dart at the wall. This year your aiming for a floating hole in the ground. What worked back then probably won't work as well now.

[MrForbes]

I don't know about that, I got to hang out with the Falcons (team 842) yesterday, and we seemed to have more success getting the ball in using the backboard and backspin, than we did lobbing it.

But it's still pretty early in the season, hopefully we'll see some youtube action this week that will astound us all

[Sean Raia]

Originally Posted by theprgramerdude

Power is speed. And pneumatics do not have power, they have huge amounts of force, at the tradeoff of speed. Power = F x V, don't lose the value of a scientific term by colloquially equating it with something entirely different.

I dont think ive lost sight of what the equation for power is. It was late at night and i was using laymans terms... He got the idea. But thanks for taking the time to go back to that and tell me what i said incorrectly

[sometimestommy]

This Thread has absolutely EXPLODED. Its great to see so many people thinking about this.

My two cents.

Speed. Both in terms of muzzle velocity and reload time.
A variable initial velocity is a great idea.
Very important.

Accuracy/Consistency. With wheels you run into the issue of spin (which
can be tweaked to even remove air resistance from the equation). Deformation is also a big problem because that compressed force will make the ball wobble when fired. (Although nominal, i need to look further into this)

Range. Simple enough. Must be consistent and long enough to provide for as many scoring opportunities.

Now. If you can set the launcher to 45 degrees and leave it there it makes the equation for finding the velocity to shoot an optimum parabola. And you can limit the number and size of moving parts with a fixed angle shooter.

(Hint Hint, Programmers this is way easier than solving an equation with both V and theta in it)

Thanks for reading!

Thomas 1939