pic: Custom Wheels

[MrForbes]

Originally Posted by Hachiban VIII

They are actually fly-wheels/roller-hubs. Hopefully they'll allow us to fire vast quantities of balls very quickly without losing speed and range.

We have a very low inertia shooter driven by one CIM with about 1.5 reduction, and we don't have any trouble with shooter speed dropping when it shoots out 5 balls in rapid succession on full speed. We do notice that the motor slows down a bit when we have the speed reduced for shorter range, but I think if we get a speed sensor on the shooter wheel and set up a feedback loop to keep speed constant, it will be fine.

Very nice shooter wheels! what's the weight?

[=Martin=Taylor=]

Originally Posted by squirrel

We have a very low inertia shooter driven by one CIM with about 1.5 reduction, and we don't have any trouble with shooter speed dropping when it shoots out 5 balls in rapid succession on full speed. We do notice that the motor slows down a bit when we have the speed reduced for shorter range, but I think if we get a speed sensor on the shooter wheel and set up a feedback loop to keep speed constant, it will be fine.

Very nice shooter wheels! what's the weight?

You appear to have misunderstood me when I said "vast quantities of balls very quickly." Think 10 balls in a fraction of a second

We actually modeled our shooter using rotational momentum, and imagined that the balls being fired were "collisions" slowing the wheel down. Adding the flywheels greatly improved consistency. Recharge went from about 1 second down to like .2 seconds. Of course we'll have to see about my math

They weigh 2.5 lbs. each. We know how much the final bot will weigh from CAD and this is a perfectly acceptable amount for us.

[MrForbes]

Sounds neat! We have trouble getting more than 5 balls per second into the shooter....shooter speed is not the limiting factor

I wonder if there's going to be a fps limit this year like in 2006?

[GaryVoshol]

Originally Posted by squirrel

I wonder if there's going to be a fps limit this year like in 2006?

Hush! Don't give "them" any ideas.

[XXShadowXX]

how well do they grip the balls, thats one issue I've foreseen, is that your flywheels won't impart enough momentum on the balls in the time that they are in contact, do you plan to say wrap them in Velcro?

[MrForbes]

gum roughtop tread works really well, there are other materials also that can grip the balls well. Velcro affects the fabric on the balls, so it's probably not the way to go.

[=Martin=Taylor=]

Originally Posted by XXShadowXX

how well do they grip the balls, thats one issue I've foreseen, is that your flywheels won't impart enough momentum on the balls in the time that they are in contact, do you plan to say wrap them in Velcro?

They're never going to touch the balls.

We'll use wedge-top or neoprene rubber for traction on the roller surface.

[Andy L]

Originally Posted by Hachiban VIII

You appear to have misunderstood me when I said "vast quantities of balls very quickly." Think 10 balls in a fraction of a second

We actually modeled our shooter using rotational momentum, and imagined that the balls being fired were "collisions" slowing the wheel down. Adding the flywheels greatly improved consistency. Recharge went from about 1 second down to like .2 seconds. Of course we'll have to see about my math

They weigh 2.5 lbs. each. We know how much the final bot will weigh from CAD and this is a perfectly acceptable amount for us.

You have managed to scare me... What's your range like?

[=Martin=Taylor=]

Originally Posted by Andy L

You have managed to scare me... What's your range like?

It was calculated at around 6'. We'll have to wait a few days to see for sure.

6' is more for awesomeness. I doubt we'd risk such a long shot in a match. 2-4' is more reasonable.

[MrForbes]

Have you dont any prototyping with a flywheel shooter?

[Andy L]

Originally Posted by Hachiban VIII

It was calculated at around 6'. We'll have to wait a few days to see for sure.

6' is more for awesomeness. I doubt we'd risk such a long shot in a match. 2-4' is more reasonable.

Wow, someone that thinks the same as our team. I see all these shooters shooting across shops for some reason, well I hope I get to see it in action at SV and Davis(are you guys at Davis this year?) on our side of the field preferably.

[RogerR]

Originally Posted by Hachiban VIII

You appear to have misunderstood me when I said "vast quantities of balls very quickly." Think 10 balls in a fraction of a second

We actually modeled our shooter using rotational momentum, and imagined that the balls being fired were "collisions" slowing the wheel down. Adding the flywheels greatly improved consistency. Recharge went from about 1 second down to like .2 seconds. Of course we'll have to see about my math

They weigh 2.5 lbs. each. We know how much the final bot will weigh from CAD and this is a perfectly acceptable amount for us.

I'm curious about your set-up; are you using some sort of clutch system to link these to your 'shooter'? traditional wisdom says that by adding rotating mass, you increase spun-up time (I assume this is what you mean by 'recharge'), though I doubt that an orbit ball would significantly effect the RPMs of these beasts.

Ironically, one of my teams went the exact opposite direction, minimizing roller mass, and instead using the shooting motors themselves to give a high rate of fire.

[=Martin=Taylor=]

Originally Posted by RogerR

...traditional wisdom says that by adding rotating mass, you increase spun-up time (I assume this is what you mean by 'recharge'), though I doubt that an orbit ball would significantly effect the RPMs of these beasts.

Yes that is correct.

Spin up time will be reduced, but less speed will be lost per shot, so it will be easier to maintain speed.

By constantly spinning the drum slowly we can ramp it up to firing power quickly whenever the need arises.

It is useful to reduce mass from the center of the rotating object, since this mass will not be spinning as fast as that on the edges. This is why we milled out the center. All the mass is on the periphery.

We actually built a very similar dual-ball shooter in '06 that suffered a great deal from recharge. Sitting on top of the ramp, it could only get the first two balls in before it lost speed.