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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.

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.

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.

Honestly anything with the dimpled surface of the golf ball would really help your consistency, or at least distance.

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??

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?

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.

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??

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.

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.