Best Way to Shoot the Balls??

[Cyber Punk 234]

Truly Im not 100% sure but I cant wait to build.

[Nitroxextreme]

During our brainstorming session yesterday we came up with a few ideas as to how to shoot the ball.
However, there was one that we came up with that I just can't see working. We thought of using a spring, sorta like a pinball machine, and having a winch pull it back. I just see this being extremely slow, needing a long pull length and not being consistent unless we use a hookean spring.

[ben281]

yes, you are correct. a spring would require many mechanisms to get it to work, including a pull back and releasing mechanism, along with a way to load the balls. also springs do not scale up well. if we were shooting pinball balls it would be much more feasable.

[Mark Pettit]

I am no engineer and I certainly am not a ballistics expert, so correct me if I am wrong here. . . .
Rifiling works excellently to stabilize the flight of a cylindrical object like a bullet or missile but would it not cause a spherical object like a Poof-Slinky ball to curve? Somehow that doesn't sound like it would be more accurate to me.

[Masterfork]

Originally Posted by sciguy125

I was thinking about rifling also. The main problem with putting groves in the barrel is that it would either cut up the ball or simply slow it down too much. I was thinking about adding a set of rotational wheels. If there's a set of wheels mounted perpendicular to the "launching" wheels, it could spin the ball. You'd probably have to use a set of omniwheels though. You'd also have to make sure that the barrel is relatively low-friction.

For a little bit today, we were considering a gatling gun style device. Had it not been discounted for impracticality, it would have been pretty cool.

LOL WELL WE LOOKED AT rifling but the thing is it is to complex but if u are trying to get a spin on the ball of that sort try doing what some paintball barrels do. which would be cut holes in a spiral sequences around the barral to let the air flow give it some spin, that was one way i could imagine doing it farely but rifling it by cutting or putting grooves would slow it down tramendously but that is what happens in a gun. i would also imagine that actual rifling would cut up the ball. also one way could be to sort of making a slight elavation in the inside surface of the barrel and spiral it to do the spinning. something I would also like to say is that it would prolly be a waste of supplies and time to try to rifle it becuase the rifling works so well with a real gun is because the bullet is actaully sealing the barrelfrom the charge so it can use the propulsion of the powder or gas made by it and grip the grooves of the barrel . which means applying it to this game would mean those balls would have to be a tight fit to grip the rifling or spin as well as a bullet.

and shooting balls with rifling well at least when i muzzle load with lead balls the rifling makes the balls rise(not curve it stays on a straight path it just rises at a distance) to a small extent at like 50 yds on a muzzleloader but very acurate still just keep that in mind if u found a way to impliment it because it might be affected in the same waybut if successful please tell me how because i would really like to see how that would work and how well it would too but i would not recommend the waste of time it might involve

[Masterfork]

Originally Posted by Nitroxextreme

During our brainstorming session yesterday we came up with a few ideas as to how to shoot the ball.
However, there was one that we came up with that I just can't see working. We thought of using a spring, sorta like a pinball machine, and having a winch pull it back. I just see this being extremely slow, needing a long pull length and not being consistent unless we use a hookean spring.

and u have to take in to play the rule about stored energy cus we were thinking along those lines and just think of how much energy it would use to pull the spring back in a match and how many times during it too, to be affective

sorry about the 2 posts in a row
just found a new thing to comment sorry

[Kevin_547]

it seems that most ppl are toying with the softball pitcher idea to shoot that balls. which i think is a very good way of doing so but how is everyone thinking how u are going to get the balls from ur holding area to the wheel to shoot without over loading ur gun or shooter or w/e u want to call it.

[EricH]

Originally Posted by Kevin_547

how is everyone thinking how u are going to get the balls from ur holding area to the wheel to shoot without over loading ur gun or shooter or w/e u want to call it.

That remains to be figured out, assuming teams use a holding area. One of our engineers had an idea, but what that is is a secret.

[Masterfork]

Originally Posted by EricH

That remains to be figured out, assuming teams use a holding area. One of our engineers had an idea, but what that is is a secret.

well that is what peoples creativity comes in which will be interesting

[Kelvin Ng]

my dad had some awesome ideas. I just wonder about jamming. Is it possible that a pile of balls may interfere with each other's ability to load? Kind of like how 2 balls may get stuck in a funnel and neither actually falls into the hole that is designed to fit one? If that is unclear, sorry I'm not the best person at explaining things.

Is probably best for the shooters if the balls are stored single file to prevent jamming. Boy, I want to go present all my ideas to my old school's team, but as an alumni(us) (which is singular?) I want to leave all the creativity to the students. I just hope they ask me for ideas =).

BTW.

if anybody does not want to use baseball-style guns to fire, I experimented with a scaled down catapult made out of lego. It uses a couple elastics (the more elastics/springs, the more stored energy), to store energy, and the accuracy is surprisingly good. I was able to score little blocks of lego in the 1 foot diametre lego basket from approximately 2 metres away at nearly 100% accuracy. However, there was some awesome recoil from that thing.

[rufu5]

Is there a limit to the amount of force we are allowed to have stored in a spring on the robot? or does the projection of the ball by that method just have to follow the 12m/s rule?

Has anyone figured out how much power it will take to keep a softball-style shooter going? Seems like all that freewheeling would kill the battery.

[Masterfork]

Originally Posted by WebWader125

Has anyone figured out how much power it will take to keep a softball-style shooter going? Seems like all that freewheeling would kill the battery.

we thought about that but u have to put in to thought that once u get it going the momentum is what will save the battery life because it will take less energy to keep it going

[Tatsu]

Flywheel and a good PID will prevent your motor from overworking. Its not that bad. And, just shut it off if you're not using it =)

My question is, is 12m/s muzzle velocity? if so, if we move the entire launcher assembly by some v, we'll have a ball traveling > 12 m/s but with a muzzle velocity of < 12 m/s..

[insub2]

Originally Posted by Kelvin Ng

I just wonder about jamming. Is it possible that a pile of balls may interfere with each other's ability to load? Kind of like how 2 balls may get stuck in a funnel and neither actually falls into the hole that is designed to fit one? If that is unclear, sorry I'm not the best person at explaining things.

it is possible to have two balls jam. the teams will just have to design a way around that. stored single file, yes, or a take a field trip to some factories. i did some temp work on an assembly line one summer and was amazed by all the machines used to move things around. a few that come to mind as aplicable would be a pinwheel on the bottom of the hopper to break up jams if they were to occur or a slowly contracting space (like a funnel but with steeper sides).