Ball Launchers? Ideas?

[sometimestommy]

Hey there. Today we discussed various launchers.
Spring Loaded
Throwing Arm
Pnuematics?

Any ideas? Pro/Cons?

Thanks!
Thomas 1939

[the man]

I want to see the animation robot with the plunger to pick up balls and the boots that spin to kick them. Could you do that please. It would be very awesome.

[Anupam Goli]

I'm actually thinking of a conveyor belt going from an intake roller all the way up to 2 wheels that spin like pitching machine wheels to launch the ball. 45 degree angle for maximum distance, adjustable speed on the wheels for height.

[Peyton Yeung]

Originally Posted by sometimestommy

Hey there. Today we discussed various launchers.
Spring Loaded
Throwing Arm
Pnuematics?

Any ideas? Pro/Cons?

A con is reload time. It takes all of those systems time to reset for the next shot.

Originally Posted by Wing

I'm actually thinking of a conveyor belt going from an intake roller all the way up to 2 wheels that spin like pitching machine wheels to launch the ball. 45 degree angle for maximum distance, adjustable speed on the wheels for height.

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.

[davidthefat]

Something similar to this, but "tank treads" instead of wheels

[sometimestommy]

Ive worked out an equation for trajectory that will hit an exact point (middle of hoop) based on a fixed theta (angle of launcher) and a variable velocity (wheel or spinning boot speed)

Its still the FIRST day of this build season so we will have to see

[sometimestommy]

So the rules dont have a maximum "Muzzle Velocity" hmmmmmmm

[MrBasse]

We actually discussed the tank tread idea as well, but one of our mentors brought up a really good point. How many commercial pitching or throwing machines do you see with tank treads? With a foam ball especially, the shortest amount of time that the ball can be in contact with the wheels will not only benefit the condition of the balls (if the belts spin at different speeds at all, the ball spins and it could do some damage to game pieces), but also will help with size, weight, and ease of construction of the mechanism.

[Starke]

Originally Posted by the man

I want to see the animation robot with the plunger to pick up balls and the boots that spin to kick them. Could you do that please. It would be very awesome.

Check out 1771 on FRC Designs Gripper page (See Link Below). This arm used a suction system to grab the ball and then used a device to launch the ball.

http://frc-designs.com/html/grippers.html

Matt

[Grim Tuesday]

Originally Posted by Starke

Check out 1771 on FRC Designs Gripper page (See Link Below). This arm used a suction system to grab the ball and then used a device to launch the ball.

http://frc-designs.com/html/grippers.html

Matt

I wish FRC Designs had some stuff from '06...

[nighterfighter]

Originally Posted by Starke

Check out 1771 on FRC Designs Gripper page (See Link Below). This arm used a suction system to grab the ball and then used a device to launch the ball.

http://frc-designs.com/html/grippers.html

Matt

Yup, it was a big funnel with an impeller for suction, then 4 pneumatic cylinders that shot it out.

We also used 2 smaller suction cups in 2010 for the soccer balls. Although we got through 1 regional with them, we quickly switched to a roller design before championships. The problem with the soccer balls (and probably these foam basketballs) is that it isn't an even surface, so it was hard for the suction cups to get and keep suction on.

[burnzkid]

At first we considered a crossbow kind of idea, but now we're moving onto something a little bit more akin to some of the winners from '06.

[Anupam Goli]

I would steer a bit away from 2006 mechanisms. Those mechanisms had a maximum muzle velocity, and they shot through a hole in the wall, not a hoop with a backboard.

The concept seems fine, but those designs need major mods to make them work with this game.

[seg9585]

As a 2006 FRC participant (Aim High) who built a robot using the pitching machine launcher design, I have a few comments about it:

First off, calibrating the wheels ended up being a little more annoying than expected. Even though we used encoders to measure and even out the speed between each wheel, we found the release angle was still inconsistent -- the balls needed to be squeezed by the wheels a bit to get the traction needed to accelerate the ball, and the balls would end up flinging a bit to the right or left depending on which wheel made contact with the ball first and how the ball re-expanded.
For Aim High this wasn't a big deal because the target was relatively large, but with baskets this year we need a lot more precision.

Also, the ball originally came out without spin, so the balls flew like a knuckleball, making scoring unpredictable. We changed the speed of one wheel to add spin, but then had to apply a directional bias since the spin did induce lift on one side of the ball (still better than a knuckleball)!

Lastly, we had to run those large softball wheels with CIM motors to get them spinning fast enough, but when they were on all match it quickly drained our battery. In later matches we had to turn off the spinner during collection periods just to save power, then wait for the wheels to spin up to speed again.

I did see effective single-wheel launchers against a static surface that took out a lot of the multi-wheel variable issues we had, and they seemed to work well.

[burnzkid]

Originally Posted by Wing

I would steer a bit away from 2006 mechanisms. Those mechanisms had a maximum muzle velocity, and they shot through a hole in the wall, not a hoop with a backboard.

The concept seems fine, but those designs need major mods to make them work with this game.

We're looking into programming the Kinect to help control an aim-able barrel, depending on distance from the hoop and which hoop we're aiming for.