Full Court shot [Archive]

bfk

21-01-2013, 14:38

A bit of tweaking yesterday and our shooter was hitting the high goal at full court length. More consistent at shorter ranges, but getting a goal from 57 feet was fun.
Video (http://youtu.be/SNoQddRJ7sA), of course.

This is after we did some weight balancing on the stock AndyMark pneumatic wheel.

Onward to our anti-gravity climbing device.

DonRotolo

21-01-2013, 14:42

Nice video. That looks awesome. I assume you know there might be a pyramid on the field, so that's why you programmed in that little curve at the end....

Jay O'Donnell

21-01-2013, 15:13

Very impressive! Was it a one in a million type shot, or something more repeatable? Either way it looks really cool!

bfk

21-01-2013, 23:09

Nice video. That looks awesome. I assume you know there might be a pyramid on the field, so that's why you programmed in that little curve at the end....

Of course.

bfk

21-01-2013, 23:14

Very impressive! Was it a one in a million type shot, or something more repeatable? Either way it looks really cool!

It was about a one in five shot. With quite a bit of variance in the trajectory. Once the Frisbee goes past its vertical peak it becomes incredibly sensitive to even tiny variations from horizontal at launch. Well at least ours do.

We spent some more time balancing the wheel today and got it a bit straighter, but we're more concerned with shorter shots, that one was just too neat not to post.

Those wheels and the hubs have enough play to rattle anything apart. In today's tests one of the students said "It's much smoother, the floor isn't vibrating enough to make my legs numb."

vinnie

22-01-2013, 13:20

Hello bfk,

What motor are you using to drive the pneumatic wheel? The results look great!

JesseK

22-01-2013, 13:42

Hello bfk,

What motor are you using to drive the pneumatic wheel? The results look great!

Answer is found in the Youtube Description:

Prototype shooter sinking the Frisbee at 57 feet. Single CIM running at about 90% power with AndyMark pneumatic wheel.

vinnie

22-01-2013, 13:45

Hello bfk,

What motor are you using to drive the pneumatic wheel? The results look great!

neshera

22-01-2013, 14:12

Jay O'Donnell

22-01-2013, 14:26

We spent some more time balancing the wheel today and got it a bit straighter, but we're more concerned with shorter shots, that one was just too neat not to post.

Those wheels and the hubs have enough play to rattle anything apart. In today's tests one of the students said "It's much smoother, the floor isn't vibrating enough to make my legs numb."

We had that same problem, which was causing some variance in our shot accuracy. We might've had a chance of making some shots like you're own, but they would've been very rare. Very impressed by your work!

neaanopri

22-01-2013, 20:23

Out of curiosity, what gear ratio were you using?

dtengineering

22-01-2013, 21:22

Brandon_L

22-01-2013, 21:31

That looks like the AM Pneumatic wheel. Were also using that, but it wobbles insanely. How did you manage to fix that? Yours looks pretty stable.

bfk

23-01-2013, 01:19

I fear I'm opening up a can o' worms here, but does anyone think the long shots, i.e. from more than half court or so, will be affected by air currents/movement much? The shorter shots seem to not rely much on the disc floating. Is there much air movement inside a typical arena?

I suspect that will be very venue dependent, unless they crank the bass way up on the PA, just to even things out between venues. Oops, maybe I shouldn't have said that.

bfk

23-01-2013, 01:20

Out of curiosity, what gear ratio were you using?

Gears? We don't need no stinking gears!

It was direct drive off a CIM, running at about 90% power.

bfk

23-01-2013, 01:21

Before I go all "safety mode", let me just point out that is a very cool shot and I'm pretty impressed. Okay... now its time for the tech inspector in me to express a concern...

I know this is just a prototype, and that you're probably already planning a safety shield for this shooter, but I think teams should be aware that not only are these wheels not designed to spin at high RPM, but that they store a significant amount of finger-ripping energy when they do.

It is much easier to build safety shields in to your design than to add them as part of tech inspection!

Thanks,

Jason

Definitely a design consideration. I personally need all the limbs and eyeballs I currently have, and I assume other feel the same way.

bfk

23-01-2013, 01:33

That looks like the AM Pneumatic wheel. Were also using that, but it wobbles insanely. How did you manage to fix that? Yours looks pretty stable.

Basically, first of all make sure your motor mount is very stable.
Make sure the hub is perfectly centred on the wheel. We used some thin grippy material between the wheel and the hub to prevent it slipping. Make sure all six bolts are tight.
Then find a piece of something that can fit in the hole in the hub and suspend the wheel like a plumb bob. You'll see it list a lot to one side or the other. The weight of the fill tube leaves it way off balance. Attach weights to the wheel until it balances as perfectly as you can get it. Make very sure that the weights are securely attached, these wheels are really moving fast and a couple of grams at that speed will do serious damage. See Jason's post above.

Then everything is great and hopefully your team-mates will have developed the world's best climber while you were working on the shooter. That part didn't work out that way for us, but a guy can dream.

TeamUpNext3528

23-01-2013, 09:39

WoW! That was awesome! Our team is going for the same approach. We are wanting to shoot full court shots. But that really depends if our shooter is accurate enough.

And I do agree, there could be air flow getting in the way of those long shots depending on where the regional is.

Willyspu

23-01-2013, 23:30

Any tips on balancing the wheel?

z_beeblebrox

23-01-2013, 23:37

Any tips on balancing the wheel?

Our team stuck a couple of long screws to the inside of the wheel opposite the valve. It seems to be working so far...

Akash Rastogi

24-01-2013, 01:03

Here's our full court shot - http://www.youtube.com/watch?v=rNT5cvXdsyk&list=PLpnmyvq38NB11eC2oV38eXefcZvJchc5w&index=5

rai337

24-01-2013, 06:25

Here's our full court shot - http://www.youtube.com/watch?v=rNT5cvXdsyk&list=PLpnmyvq38NB11eC2oV38eXefcZvJchc5w&index=5

what wheel you used? we've been trying pneumatic wheels and rubber wheels and the pneumatic wasnt stable, while the rubber didnt have much power..

Orion.DeYoe

24-01-2013, 12:13

Before I go all "safety mode", let me just point out that is a very cool shot and I'm pretty impressed. Okay... now its time for the tech inspector in me to express a concern...

I know this is just a prototype, and that you're probably already planning a safety shield for this shooter, but I think teams should be aware that not only are these wheels not designed to spin at high RPM, but that they store a significant amount of finger-ripping energy when they do.

It is much easier to build safety shields in to your design than to add them as part of tech inspection!

Thanks,

Jason

This is definitely a valid point. One our team has considered as well. We are not using the AM Pneumatic Wheel but we attached "Shrapnel Guards" as far around our wheels as we could, so if the wheels wear out and fragment they won't fly out and hit anyone.

tickspe15

20-02-2013, 14:40

Don't have a video yet but we were shooting above 90 percent into the 2 point goal from the feeder station. And able to get one load of 4 Frisbees every 10 to 15 seconds

SciBorg Dave

20-02-2013, 15:17

Any tips on balancing the wheel?

Team 4061 went to a tire store and got stick on wheel weights.
The valve stem was the heavy spot so we added 2 wheel weights at 120 and 240 degrees from the valve stem. This gave 3 points of weight the valve stem and the stick on weights. We had to use 1/4 oz at the 2 points. This worked very well to rid vibration.