Anyone thinking NERF ball turret
 

is anyone thinking about using a turret on their robot?

i personally don't like air power but im just wondering if anyone will be thinking about shooting with air

Re: Anyone thinking NERF ball turret
 

if you mean as in air pushing the ball down a barrel. i thikn its impossible. from the size of our tanks vs diameter of the ball and the 60psi regultion doesnt hlp either

Re: Anyone thinking NERF ball turret
 

what about the catapult

is there anyother way to do a robot that could fire a ball

Re: Anyone thinking NERF ball turret
 

You'd have to check the rules to be sure, but I believe all air systems have to be closed.

Re: Anyone thinking NERF ball turret
 

darn what about a pitching machine if we cant use air

Re: Anyone thinking NERF ball turret
 

One of our team mentors is noodling about a system where the ball is placed in a launching tube, and then smacked with a spring-loaded paddle (like a giant ping pong ball). The spring-loaded arm would be cocked either by pneumatic cylinders or a low-RPM motor assembly. I'm not saying we are doing this, by the way, but it is one of the out-of-the-box ideas we are (kind of) considering.

Re: Anyone thinking NERF ball turret
 

hmm that sounds like a good idea

but wouldnt the foam absorb some of the shock and keep the ball from moving as fast

Re: Anyone thinking NERF ball turret
 

Is there not certain rules around using springs as well?

Re: Anyone thinking NERF ball turret
 

I wouldn't say "we can't use air". I'd say we have to be creative in how we use it.
Think of punching the ball instead of "spitting" it out with air.

I happen to agree that we don't have the air volume with the two Clippard's we are limited to. But if you use their air wisely, you just may be successful. :yikes:

Re: Anyone thinking NERF ball turret
 

what about using a pool cue like object at a high velocity?

that may work

Re: Anyone thinking NERF ball turret
 

We did rule out an air pressure design, but we did look at a different type of nerf gun similar to a softball pitcher.

http://www.bangzoomdesign.com/ripsaw.html

This nerf gun has a loose barrel and the wheel puts a really nice back spin on the ball. Its very accurate for a nerf gun.

Re: Anyone thinking NERF ball turret
 

Before you spend too much time on this idea, try this simple test: put your mouth on the ball, making a reasonably tight seal against the surface, and blow. Surprising, isn't it?

-dave

Re: Anyone thinking NERF ball turret
 

My team has been thinking about it pretty seriously, but we're a rookie team, so we don't really know what we're doing. I'm checking frantically through the manuals to make sure this is legal. I haven't found anything, but can anyone here confirm that we can do it?
The thing about 'no open systems' worries me.

Re: Anyone thinking NERF ball turret
 

Turrets are very legal.

the big issue for our team is side-loading vs bottom-loading.
We are actually probably going to end up with the launching device being part of the turret with just as much movement allowed., Remember, the longer the ball stays enclosed without direct propulsion, the slower and less accurately it will go

the 'no open system' refers to the covering of fast/dangetously moving parts. There have been some pics up of teams launching through two fast-moving belts and for safety reasons, the final model will need to have those belts covered from the outside. The same will go for spinning gears and wheels that could possibly come in contact with another bot.

Re: Anyone thinking NERF ball turret
 

I can't get my mouth to fit around the 7" ball.

But, I think your point is, if the ball has a tight seal and is restricted from moving until the pressure builds sufficiently*, then some surprising force can be generated.

*Sufficient = you do the math

Don

Re: Anyone thinking NERF ball turret
 

Thanks.

Re: Anyone thinking NERF ball turret
 

What I ment about no open systems, was that you cannot design the air system just to dump to the atmosphere such as an air cannon design. Now that was my belief but upon scaning the rules I found nothing to back that up. So perhaps that is not the case. Would anyone like to offer input on that?

Re: Anyone thinking NERF ball turret
 

At the kickoff they spent an awful lot of time talking about the softball launcher - surely they wouldn't have been misleading us would they?
Are softball launchers compatible with a tube? Would it improve accuracy or put sidespin on the ball, forcing it to hook or slice?
And I know you're not Shirley.

Re: Anyone thinking NERF ball turret
 

They wouldn't intentionally provide misleading information in the official presentation of the game. However, the game with the rocking ramp (Diabolical Dynamics?) was won using a scheme which ignored the example of a single robot balancing on the ramp while holding on to one goal at each side. The teams who followed that example lost the opportunity to have all four robots score bonus points at the end of the match.

So consider well your options. A spinning-wheel ball launcher is an obvious choice, but it might not be the winning one.

Re: Anyone thinking NERF ball turret
 

yeah i thought that a spinning-wheel launcher would be a real common feature on most of the robots. I dont know if we are still considering even using a cannon or pitching machine on our robot

Re: Anyone thinking NERF ball turret
 

Surprisingly the cannon extension will not provide as much accuracy as you may think. At least that is what we found from our prototyping.

Re: Anyone thinking NERF ball turret
 

You could use a spring then pull back a plate inside the turret with a winch. It would be semi simple design that would follow regulations.

Re: Anyone thinking NERF ball turret
 

What i have figured out, there are only 4 plausible ways of firing a ball.
1. Single wheel shot (pitching machine on kickoff video)
2. Multiple wheel shot (more advanced pitching maching, look at a batting cage)
3. Catipult
4. Pneumatic piston/spring shot (both similar in a platform pushing the ball out)

Re: Anyone thinking NERF ball turret
 

Don't forget "Flywheel to linear transition" thrower"...

Re: Anyone thinking NERF ball turret
 

Can you show me an example. i can up with this basic list in like 2 min, so i want to know what the fly wheel to a linear transition is?

Re: Anyone thinking NERF ball turret
 

I'm not sure if this is what Blair was going for but this is what i'm envisioning. First place a ball on a cart like object that can carry the ball and make it travel on a short track. Then take a flywheel and bring it into contact with the cart to accelerate it. the cart should travel until it hits a stopper making it stop and any ball on it flying off. It seems like a nice compromise between a flywheel and some other sort cannon mechanism. You get consistency because you're always shooting the same cart object, but it isn't quite as fast and quickly repeatable as a straight flywheel. If you springload the cart so that it automatically comes back you wouldn't have to devote another motor the cart mechanism.

Re: Anyone thinking NERF ball turret
 

that still is categorized in the one wheel system, its just a small modification.

Re: Anyone thinking NERF ball turret
 

Eh, something like like. Your's is better. There was a thread on here before about converting rotational into linear motion. That was what I referring to. But it seems rather feasible. The other option is to have a flywheel somehow coupled to a rod so that you can throw the rod forward. Rod hits ball, ball goes out.

Re: Anyone thinking NERF ball turret
 

that might be fine as long as you remember that the ball we are using for the game is made to absorbs force so it would require 2x the force to send the ball the same distance. plus a spring would constantly lose it rebound as the match went on.

Re: Anyone thinking NERF ball turret
 

think crankshaft or camshafts too

also how about gravity fed trbuchet style or bow and string mangonels. crossbowish stuff.
so basically simply put the list gets to be

angular kinetic energy (flywheels and the such)
gravitational potential energy (obvious)
elastic potential energy (bows. cross bows. springs. bungees)
compressed gas
electrical(as in motors so i guess this is kinda angular kinetic)
mind power(technically unless you need to send radio waves from your head you dont even need to have the driver do this. someone in the stands can do this.. and even shoot down opponent's shots. but maybe violates GP? i unno
some sort of chemical reaction or sumthing. probably not legal

Re: Anyone thinking NERF ball turret
 

that was like the post of the day for me. ahahahaha. Like Wonderboy, mind bullets. (Tenacious D reference for all you newbs)