Air Trajectory B/C

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joeyjoejoe
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Re: Air Trajectory B/C

Post by joeyjoejoe » October 15th, 2014, 8:05 am

Anybody using Ping-Pong balls seeing wild curving of the balls especially when launching in the 8m range?
As an example of how much inaccuracy we are seeing, ours can launch over 20m and if you were to launch 50 balls that far, the "debris field" would be roughly an ellipse 30 ft wide and 15 ft long.

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Re: Air Trajectory B/C

Post by JonB » October 15th, 2014, 8:07 am

joeyjoejoe wrote:Anybody using Ping-Pong balls seeing wild curving of the balls especially when launching in the 8m range?
As an example of how much inaccuracy we are seeing, ours can launch over 20m and if you were to launch 50 balls that far, the "debris field" would be roughly an ellipse 30 ft wide and 15 ft long.
Sounds about right. Ping-Pong balls will pretty much always do that. And to clarify- you can launch a Ping-Pong ball over 20 meters?? Sounds like there is plenty of force- enough to use a golf ball instead.

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Re: Air Trajectory B/C

Post by joeyjoejoe » October 15th, 2014, 8:53 am

Very astute observation! We did move to plastic golf-balls due to them being slightly heavier than Ping-Pong balls. I'm just used to referring to Ping-Pong balls.
Anyhow, the Ping-Pong balls have the same problem with inaccuracy but (and I just checked) launch about 11 m max.
Anybody tested out any other type of practice golf balls? We were going to try the foam ones but Walmart only had a bag of 50 for $23.99! Too rich for my blood.
Last edited by joeyjoejoe on October 15th, 2014, 9:15 am, edited 1 time in total.

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Re: Air Trajectory B/C

Post by iwonder » October 15th, 2014, 9:01 am

Honestly anything with the dimpled surface of the golf ball would really help your consistency, or at least distance.
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Re: Air Trajectory B/C

Post by retired1 » October 17th, 2014, 9:19 am

I am amazed on your being able to launch a ping pong ball that far. Can you share what you were using for a bellows/piston???
What have you found to be a suitable tube for the plastic golf ball??

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Re: Air Trajectory B/C

Post by cifutielu » October 23rd, 2014, 7:46 pm

Right now our team is using compression on a soda bottle to launch a plastic golf ball. It's working pretty well, except the bottle doesn't return to ambient pressure. How can we get it to inflate back up again by itself?

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Re: Air Trajectory B/C

Post by actionpotential » October 23rd, 2014, 8:06 pm

Really compressing soda bottles works? I saw a couple images of that, but I didn't think it would shoot reliably. I imagined dropping a mass wouldn't compress the bottle the same way every time, so the shots wouldn't be reliable.

Also, after your shot, if the pipe that's connected to your bottle is open to the outside, the air inside the bottle would automatically return to ambient pressure. The bottle would not completely be inflated, but the air would be at the same pressure as your surroundings. So you should be fine.

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Re: Air Trajectory B/C

Post by retired1 » October 24th, 2014, 7:28 am

Yes, it will make a big difference. You simply blow in the end of the tube and the bottle will go back to near normal size.

What are you using for a tube? any modifications to it??

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Re: Air Trajectory B/C

Post by iwonder » October 24th, 2014, 10:33 am

cifutielu wrote:Right now our team is using compression on a soda bottle to launch a plastic golf ball. It's working pretty well, except the bottle doesn't return to ambient pressure. How can we get it to inflate back up again by itself?
If there's no valve on the inlet to the bottle I don't see why it wouldn't return to ambient pressure. It's going to stay deformed (crushed) but the pressure inside will still be ambient, just at a lower volume.
'If you're the smartest person in the room, you're in the wrong room' - Unknown

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Re: Air Trajectory B/C

Post by retired1 » October 25th, 2014, 12:45 pm

The crushed bottle will be about a quarter volume of the expanded bottle. I seriously doubt if you will get 9 meters with a crushed bottle. 3 meters might not be possible.

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