Allowing the Ball into the shooter

[Mr. Steve]

One of the things our team has had trouble with is what allows the ball into the shooter. We've been trying to use servos with 4 inch arms, but while that works most of the time, it's not quite ideal.

How does everyone else do it? Pictures?

[steven114]

We have a rolling axle which compresses the ball so it can't get through unless the axle is spinning.

[sanddrag]

We use a globe motor with an arm on it, but that was giving us some jamming problems too. A servo does seem a bit small/weak for the job though.

[nuggetsyl]

use gravity


shaun

[John C]

we use a 6" wheel chair wheel powered by a globe motor to control the flow of balls into the shooter. it pushes the ball right up to the shooter wheels. it allows us to control the rate of fire to give the shooter wheels time to speed back up in between shots to give us good accuracy.
there is a picture here:
http://www.chiefdelphi.com/forums/pi...&quiet=Verbose

[Mr. Steve]

Originally Posted by nuggetsyl

use gravity


shaun

Yes, the way it is now, technically gravity is brining the ball into the shooter.

I guess the new question is, how to stop the ball from going into the shooter?

[Cheuk Hung Ng]

We use a gravity fed chute to hold the balls. At the bottom of the shoot is a small wheel attached to a globe motor to stop the balls from going into the shooter. This allows us to spin the shooter up to full speed, then allow the balls to enter the shooter by running the globe motor and the small wheel attached to it.

[DanDon]

We are using a gravity feeder with a 3/4 in bore 3 in stroke bimba to control the flow of balls.

[Rombus]

What about using 2 plexi plates of some sort? you could make a U slot on either side to let the plates ride on, and then your servo should be strong enough to pull the plexi out of the way. They don't have to be full size, just big enough to not let a ball go though.

Our robot uses a conveyors to pick up balls from the base of the hopper and bring them up to the shooter. Since our shooter design spins up incredibly fast, we simply have the shooter and conveyor tied to the same trigger on the joystick. i think we have less than half a second spin up on our shooter, so the only way a ball wouldn't get launched full distance is if it was directly against wheels before we attempt to launch. Here is a thread with a video of our conveyor in action: http://www.chiefdelphi.com/forums/sh...654#post465654

[Wayne Doenges]

We are using a gravity feeder with a 3/4 in bore 3 in stroke bimba to control the flow of balls

Do you have any problem with impelling the poof balls

We have a gravity fed magazine to get the balls to our elevator. Our elevator is two O-Rings driven by the FP motor/tranny. This allows us to control when the balls are fed into the shooter.

[Jonathan Norris]

We are using a conveyor belt system which stops just before our wheels grab the ball. As long as you end the conveyor belt at the right time it works great. Pic: http://www.chiefdelphi.com/forums/sh...&highlight=610

[mechanicalbrain]

Originally Posted by sanddrag

We use a globe motor with an arm on it, but that was giving us some jamming problems too. A servo does seem a bit small/weak for the job though.

Actually they work very well. You might need two if you are looking at a big load though. We did two servos 7" apart with photo sensors in between. We found that under a real bad load the plastic disk we mounted to bent a bit but we strengthened it.

[Lee]

343's "Cyclone" uses a flat belt driven by a globe motor for the final feed into the shooter. Since our shooter is on top gravity just doesn't work...

[lukevanoort]

We found our servo to be more than powerful enough. However, when it was disabled at the beginning of a match, it wouldn't fight the balls. So, our first couple in auto sort of dribbled out.