My team is debating quite a bit on whether to have a hopper to hold the basketballs or not. We refer back to our lunacy days when we a hopper was basically a necessity but in this game, we aren’t sure whether it is or not. Because there are only 18 balls on the field and because we can only have 3 balls at a time, is a hopper really required or would it be easier just to hold the balls in the conveyor belt. So I ask you! Is your team thinking about using a hopper? Why or why not?
You can probably do without a hopper if you design your ball transport mechanism to store up to three balls. If you use a belt to pin balls against a surface, make sure that the balls at the top waiting to be fired can rotate in place while you load new balls from the bottom. My team probably won’t use a hopper, mostly due to the ball possession limitations.
were splitting our belt into two separate belts. The first sucks balls into the robot, the second goes to the shooter. If were not ready to shoot, we turn off belt 2 (to the shooter) but we can leave belt 1 (sucker) on. So we can still collect balls, and just hold them in the conveyor. when we are at our 3 ball max, we turn off belt 1. When were ready to shoot, we turn on belt 2.
I’ve seen a couple of other teams with a similar idea.
As stated before me, I don’t believe a hopper is required. With the rule of not being able to control more than 3 balls at a time [G22], a hopper would most likely lead to penalties, as well as a complicated design because you would need to create a method to get the balls to the hopper, and then a method for them to leave the hopper, and make sure of the unlikely event all 3 balls don’t jam it somehow. Unless you’ve made your conveyor less than about 21", you should be good for maintaining control of 3 balls. What our team has is a tower that is going to be at least 29" tall to hold our balls then a secret method to transfer the balls to our shooter mechanism. (Hint - it involves Newton )
We’re working on our design that uses a rather tall collecting/storage system, which delivers balls to a slanted hopper. The intake of the shooter is at the bottom of the hopper. The hopper can hold 3 balls. We decided we need the hopper to hold the balls so they can be fed to the shooter on demand, rather than as they pop out of the collector. We plan to use a pneumatic cylinder to push the next ball in line up into the shooter.
We decided to forego the hopper because it occupies a lot of space, and is unnecessary because of the 3 ball rule. However, I supported a small hopper because, if you had one, you could have alliance partners with effective long-range shooters feed you balls.
Max robot height is 60 inches, and the balls are less than 10 inches in diameter. I don’t think there is any reason for a full height robot to have a designated hopper.
It’s not a matter of being able to fit the balls in…it’s a matter of being able to store them, while being able to collect and shoot balls independently of the storage system. At least that’s why we figured it’s necessary.
If you’re clever, you can probably figure out a good way to store balls another way…
It seems that a full height robot is not even necessary in the game due to a lot of rules regarding defending and distance between you and opposing robots. 3 balls being collected at an angle doesn’t even need to be taller than 36". And with all the rocking and tipping that may occur when crossing the ramp or bump, a shorter robot may be better.
We can hold slightly more than three balls this year, to allow for space in between the balls between shots. Don’t see any reason to be able to hold more than that this year.
For all those not going with hoppers, think of this: Don’t use the hopper as a storage device, but another way to get balls to your shooter. Good strategy along with a design that fits will always be more successful than you think.
Just remember that if you store balls in the conveyer belt instead of inside a hopper, you need a way to keep them in place without stalling your belt. If your ball is stored next to your shooter, if your belt is running the ball will stall the belt and could burn out your motor. But then again, if your ball is rotating in place, there may not be enough friction to bring the ball into the shooter. All things our team is struggling with