2013 game idea for disk shooter

they are andymark 9015 motors going through a 5:1 gearbox then some chain reduction driving 8" wheels in the first prototype and I have no idea about the single wheeled shooter.
a timing belt and pulley setup would provide more contact time and require less gearing if high-rpm motors were utilized, and be a lighter, more compact setup.

if by one wheel you mean the semi-circularish thrower, the major downside is the space required..also it has the potential to require a more complicated loader/pickup system

I feel its good design practice to know the goods and bads of all design ideas

I could not agree more!

Guys just looked at the video of the little bit I posted , it shoot super fast. If one wheel spins faster should give proper spin, if they spin the same should give a flick motion. This style shoot looks more compacted them the 3 day build style.
Really we should maybe build 3 or 4 styles of shooter bases all using the same motor and wheels and just move motors into mounting brackets, and wheels onto mounts , that way we are using the same supplies and comparing apples to apples when it comes to motors and wheels.

Bit not bot

We should use pneumatic, or at least relatively deformable wheels, in the shooter. The idea of the shooter is similar to squeezing a sunflower seed between your fingers until it goes flying out. You are putting pressure on a projectile so that when the pressure is quickly released, it'll go flying. A slightly deformable wheel will allow it to get a bit of spring/more pressure/a tighter fit between the frisbee and wall, leading to a faster shot. Also, a deformable wheel will grip the frisbee better, as the contact patch of flat plastic against the frisbee is mere millimeters.

Plastic wheels have a tiny margin between squealing/rubbing, just bouncing the frisbee around, and a good shot. Pneumatic, or airless tyres will allow the wheel to squish, rebound, and the frisbee to fly.

You dont want to deform a frisbee, or it will become very unstable in flight.
I think a belt drive could give more controllable pressure on the frisbee since it will have a flat surface to contact the frisbee, ie: orientation wont matter for feeding, and there is less material to deform in a belt shooter system

Ken, by a belt drive do you mean like a very fast conveyor belt that propels the frisbee? I haven't seen any videos on YouTube at all of implementing a conveyor belt. Everyone uses wheels. Am I mistaken when I believe we can be spinning a wheel much faster to propel a frisbee than we can spin a conveyor belt?

I can't see a pneumatic wheel deforming a frisbee much. It's not even like they return to play. Shoot score and there they stay. I don't see a split second contact with any wheel for that matter, deforming these frisbees. They appear like they will stand up to a shooter very well.

Yes I think Sam's idea of a pneumatic wheel (or two) is an excellent idea for us to implement in the shooter. I think it's definitely worth testing to see how well it works!

I like a pneumatic wheel idea to better then a belt.
We need to test.

If by belt driven, ken , you essentially mean having two wheels driven by the same motor, i think thats going to affect the performance of the shooter
in the first shooter made for the 'robot in 3 days' videos, at least, the second wheel spinning faster than the first is what gave it spin...
though im not sure how much of a effect the difference in speed has, it makes sense to me at least that it works better than one speed for both wheels

Yes, for example, to shoot a frisbee at 14m/s, the surface of the propelling device would need a surface velocity of 28m/s. If this were a timing/synchronous belt driven by a 6" pulley would spin at 11023rpm. The pulley could also serve as a flywheel, preventing the belt from slowing down under shock loads. the "vec BAG motor" would be suitable for this application, its slightly larger than a fisher price motor and spins at 14000 rpm.

I was referring to the instability of frisbees after they leave the shooter, on their way to the goal.

wheels will only have minimal contact with the frisbee, at most a contact patch of a square inch. the force causing the frisbee to move through the shooter is friction from the wheels acting on the frisbee, and remember work=force*displacement. With a wheel you are asking for alot from the friction between the wheel and the frisbee if you want to do the same work a belt could do.

One wheel in a U shaped launcher should be tested.

from what I have seen I feel that the round shooters offer the best throwing performance of a Frisbee. The spacing between the wheel in the center and the outside fence is critical, we want the Frisbee to be tight so it rolls along the fence but doesn't deform. The RPM on the center wheel needs to be reasonably fast, a couple hundred rpm. Increasing the speed of the shooting wheel will increase the stability of the disk in flight.

The team needs to have an idea of how much space the rotational shooters will take up and decide if it is worth the performance increase over the linear shooters.

The rail shooter on the 3-day robot is interesting; there is a ram that pushes the disks into the first wheel. Increasing the RPM of the wheels in the linear design should also increase the stability and distance that the disk can fly.

For either design we will need some reasonably large motors, likely similar to wheel motors from the basketball robot.

One more point. The main reason that the rotational shooter has a performance advantage over the linear design is because the disk is handled smoothly. By this I mean the disk is accelerated smoothly and is not bumped transitioning from one motor to the next. It is one fluid motion, like throwing a Frisbee.

I agree and it is mechanically simpler but harder to make the curve outside perfect.

after giving it some thought, i think that the major drawback of the semi-circular shooter isnt its size
its that, while we are abole to reduce the number of moving parts on the shooter itself, the loader mechanism (ground pickup and/or player station feeding) will either need extra parts/stages
or things will have to moved around and rotated giving an ending result of having pickup and shooter on one side, which means turning around

a hybrid belt and wheel system might also be worth looking at.
Use a belt to feed the frisbees in over a distance then feeding it through a single wheel and have it all driven off the same motor/gearbox

http://3847.blogspot.ca/2013/01/day-11-ultimate-ascent-shooter-testing.html

This post is worth looking at, small packaging, 2-wheeled linear shooter.

CHris thank you , this video gives details about the shooter below, all members to look at this design

this shooter uses the 180 watt motors that mr smith said have a much higher rpm than the cim motors but have a much lower wattage, should we try using those instead of the cim if perhaps a higher rpm is needed

sure we neither need to gear up the CIM or increase RPM with another type pf motor, if we can use a smaller motor with a higher RPM output that would be great because it frees up CIM for use elseware.

Good observations

I like the way you have figured this out on your own.
We need 4 CIMs for drive
We need 2 CIMs for the winch.
We can only have 6 CIMs this year
We must plan on other motors

Perhaps extremely unfeasible but cool:
https://www.youtube.com/watch?v=yi7277FYUTU

A successful linear shooter I found.
http://m.youtube.com/#/watch?feature=youtu.be&v=PBvVVnQW5ME&desktop_uri=%2Fwatch%3Fv%3DPBvVVnQW5ME%26feature%3Dyoutu.be
Details on chief Delphi
http://www.chiefdelphi.com/forums/showthread.php?threadid=111700