Air Trajectory B/C

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Re: Air Trajectory B/C

Post by Phys1cs » January 19th, 2016, 8:45 am

windu34 wrote:Ya ping pong balls are the way to go if you want consistency

Be wary at first of ping pong balls, though. They're super light, so if they spin too much when launched, you can see them spin left/right on some of the farther shots.

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Re: Air Trajectory B/C

Post by windu34 » January 19th, 2016, 8:54 am

Phys1cs wrote:
windu34 wrote:Ya ping pong balls are the way to go if you want consistency

Be wary at first of ping pong balls, though. They're super light, so if they spin too much when launched, you can see them spin left/right on some of the farther shots.
Yeah you need to comne up with a very consistent device as far as air flow/movement if you want to do well with ping pong balls. Small bursts of uneven air will cause alot of problems
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Re: Air Trajectory B/C

Post by sciolylover13 » January 19th, 2016, 9:53 am

windu34 wrote:
Phys1cs wrote:
windu34 wrote:Ya ping pong balls are the way to go if you want consistency

Be wary at first of ping pong balls, though. They're super light, so if they spin too much when launched, you can see them spin left/right on some of the farther shots.
Yeah you need to comne up with a very consistent device as far as air flow/movement if you want to do well with ping pong balls. Small bursts of uneven air will cause alot of problems
So far our device has been pretty consistent with a variation of 2-3 cm using ping pong balls. Of course for Nats 2-3 cm is 2-3 cm too much, so I'm working on making it more consistent.
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Re: Air Trajectory B/C

Post by bernard » January 19th, 2016, 1:04 pm

sciolylover13 wrote:
bernard wrote: And a related question: what do you do when you can't find a ball that fits your pipe perfectly (but of course your pipe is larger than your ball)? Last season we used tape, but noticed over time it lost consistently. Started with great consistency, but over time it would somehow act weirdly (making the projectile fit very, very tightly) so not so great consistency in the long run, at least from our experience.
What ball are you using? I use plastic ping pong balls that fit a 1 1/4* in. PVC pipe perfectly.

*I bought said PVC pipe last year, so I don't remember the exact diameter of it. I'm pretty sure it was 1 1/4 though.
Was a competitor last year--we used Joola orange ping pong balls off Amazon with 1.5" PVC (and I'm pretty sure you had 1.5" PVC as that's the approximate diameter of regulation table tennis balls). It fit nicely, but was not tight enough.
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Re: Air Trajectory B/C

Post by sciolylover13 » January 19th, 2016, 1:23 pm

bernard wrote:
sciolylover13 wrote:
bernard wrote: And a related question: what do you do when you can't find a ball that fits your pipe perfectly (but of course your pipe is larger than your ball)? Last season we used tape, but noticed over time it lost consistently. Started with great consistency, but over time it would somehow act weirdly (making the projectile fit very, very tightly) so not so great consistency in the long run, at least from our experience.
What ball are you using? I use plastic ping pong balls that fit a 1 1/4* in. PVC pipe perfectly.

*I bought said PVC pipe last year, so I don't remember the exact diameter of it. I'm pretty sure it was 1 1/4 though.
Was a competitor last year--we used Joola orange ping pong balls off Amazon with 1.5" PVC (and I'm pretty sure you had 1.5" PVC as that's the approximate diameter of regulation table tennis balls). It fit nicely, but was not tight enough.
Yeah, I think it was 1.5''. I thought ours was a pretty good fit. We used white plastic ping pong balls from Academy. I don't remember the company.
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Re: Air Trajectory B/C

Post by Leznupar » January 19th, 2016, 7:41 pm

Hey, I know it's a bit late to ask for help, but Id like to know if the weight has to directly trigger the device? Im buying a spring-loaded toy gun to use to launch the ball, however, my weight would have to indirectly set off the trigger, almost like a chain effect. In addition, would the fact that the gun is spring-loaded make it induced by air pressure? I was thinking in my head that the more compressed the spring is, the more air there is to "explode" once released. Although, the gun involves a bar hitting the ball, not the actual spring itself (which Im assuming is attached to the bar at the rear).

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Re: Air Trajectory B/C

Post by windu34 » January 19th, 2016, 8:15 pm

Leznupar wrote:Hey, I know it's a bit late to ask for help, but Id like to know if the weight has to directly trigger the device? Im buying a spring-loaded toy gun to use to launch the ball, however, my weight would have to indirectly set off the trigger, almost like a chain effect. In addition, would the fact that the gun is spring-loaded make it induced by air pressure? I was thinking in my head that the more compressed the spring is, the more air there is to "explode" once released. Although, the gun involves a bar hitting the ball, not the actual spring itself (which Im assuming is attached to the bar at the rear).
READ THE RULES PLEASE!!!
You must convert gravitational potential energy into Air pressure which you use to launch a projectile.
So basically, NO SPRING
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Re: Air Trajectory B/C

Post by Leznupar » January 19th, 2016, 8:22 pm

I thought setting off a ball to hit the trigger was considered "gravitational potential energy", since it'll be going down an incline of some sort to actually hit the trigger?

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Re: Air Trajectory B/C

Post by windu34 » January 19th, 2016, 8:36 pm

Leznupar wrote:I thought setting off a ball to hit the trigger was considered "gravitational potential energy", since it'll be going down an incline of some sort to actually hit the trigger?
No. You need actual air pressure to launch the ball either directly or indirectly. A spring does not qualify
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Re: Air Trajectory B/C

Post by Fanglin » January 29th, 2016, 3:48 pm

sciolylover13 wrote:
bernard wrote: And a related question: what do you do when you can't find a ball that fits your pipe perfectly (but of course your pipe is larger than your ball)? Last season we used tape, but noticed over time it lost consistently. Started with great consistency, but over time it would somehow act weirdly (making the projectile fit very, very tightly) so not so great consistency in the long run, at least from our experience.
What ball are you using? I use plastic ping pong balls that fit a 1 1/4* in. PVC pipe perfectly.

*I bought said PVC pipe last year, so I don't remember the exact diameter of it. I'm pretty sure it was 1 1/4 though.
Even better, is a practice golf ball, which is very similar to a ping pong ball, but since it has dimples, it has less of a tendency to drift away from the desired trajectory.
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