Launching the ball with wheels???
 

My team got the idea of making a claw that ejects the ball with wheels around the centre. Is that even possible??

Re: Launching the ball with wheels???
 

A great many things are possible. This is one of them.

Whether or not they are practical is another story. Some prototyping will help to determine whether they are practical--and many a team doesn't like giving away prototyping ideas.

Re: Launching the ball with wheels???
 

You'll find out whether it's possible one of two ways:

Do the relevant calculations regarding projectile motion and wheel speed, and compare.

Prototype it yourself and see.

As for how you'll figure out whether it's possible for your team, well, only you have those requirements.

Re: Launching the ball with wheels???
 

Wheels around the center of a claw. Sounds enticing, if not a little vague, too.

Lots of catapults out there, I'm interested in seeing some wheeled shooters. In fact I might just get students to prototype this Saturday.

Re: Launching the ball with wheels???
 

I would be worried about damaging the ball fabric. Since this is kind of a heavy and big piece to shoot with some high speed wheels, you're gonna need something with enough inertia to not slow down too much while in contact with the ball during shooting. If you need something with a good amount of power to launch this ball more than 5 feet in the air, you might run into problems with damaging, or even tearing the fabric, which is against the rules, and the referees will have to address this during a match. We ran into this problem in 2012 with our shooter since the foam basketballs kept getting shredded up.

This is just my speculation, and I haven't tested this, so take what I say with a grain of salt and don't limit your possibilities. I say try it out if you think it's worth doing, and you'll have your answer soon enough.

Re: Launching the ball with wheels???
 

taking ball damage and inertia into consideration, perhaps an hour-glass shaped roller, with a good mass would be better on each side rather than 2 wheels.

The asymmetrical nature of the ball is also an issue.

Re: Launching the ball with wheels???
 

Lots of the 3 day robots had the intake with wheels, and team O-RYON used the wheels to also score in the low goal. They had another mechanism for the high goal. Wheels will work depending on what your goals are.

Re: Launching the ball with wheels???
 

Hourglass roller would be more likely to damage a ball since the surface speed is different at the different diameters. So you're guaranteed to have slip and scuffing.

Re: Launching the ball with wheels???
 

Good point there

Re: Launching the ball with wheels???
 

Just read this thread about ball damage. Caution will be the name of the game.
http://www.chiefdelphi.com/forums/sh...hreadid=124416

Re: Launching the ball with wheels???
 

Launching the balls with wheels is very possible. Check out this video.
http://www.youtube.com/watch?v=QcHGD...ature=youtu.be

Re: Launching the ball with wheels???
 

Are any teams not planning on shooting over truss or for high goal?

Re: Launching the ball with wheels???
 

What we can't see in the video is what those wheels are doing to the fabric of the ball.

Re: Launching the ball with wheels???
 

..and damage to the balls is a FOUL (blue box for G10)

Re: Launching the ball with wheels???
 

More than just TechHOUNDS have a working prototype for a wheeled shooter.

Here is a video from 2383 the Ninjineers and their design:
http://www.youtube.com/watch?v=0u_NDY-npwc

If you pause the video at about 18 seconds (close up of the ball), you can see some scuff marks but nothing more

Seems to me like a good way to approach the game

Re: Launching the ball with wheels???
 

Scuffs from a high speed wheel shouldn't be taken lightly.
Scuff marks in Ultimate Ascent turned into gouges in discs.
Scuff marks in Rebound Rumble turned into chunks of foam missing from basketballs.

That said, it still works really well as a directed shooter. I'd like to see some different wheels tested.

Re: Launching the ball with wheels???
 

Yup, we are using a wheel shooter.

So far the ball hasn't popped haha. We're using plastic treaded wheels and have found that each tread kind of scuffs the ball. But I think this could be solved by a smooth wheel.

If the ball gets a lot more damage, we'll try smooth wheels.

But all in all, wheels are a viable option!!

Re: Launching the ball with wheels???
 

Be sure to read the blue box at the bottom of G10 regarding ball damage.

Re: Launching the ball with wheels???
 

^^^ This

Re: Launching the ball with wheels???
 

Just out of curiosity how many teams got called for fouls last year for marking discs?

All of our test discs have the rims marked up and a lot of them are blue. We were never talked to by the ref or field crew.

Re: Launching the ball with wheels???
 

Our belts always left residue on the discs....not a single foul

Re: Launching the ball with wheels???
 

Yes, but there were 30-50 disks being launched if not more throughout the match and they could not really keep track of whereas in this game there is at most three balls in play at the beginning for each alliance, which later goes down to one. I fell that they can keep track of the ball damage easier this year.

Re: Launching the ball with wheels???
 

It's a specious analogy.

The 2013 discs were cheap, durable, not at all likely to fail catastrophically, and not likely to affect the game outcome if one was damaged during a match

The 2014 balls are expensive, easily damaged, very likely to fail catastrophically if mistreated, and potentially could affect the game outcome if one is damaged during a match.

Apples and oranges.