Diameter of Neck

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scioly2
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Joined: Thu Nov 12, 2015 10:57 pm

Diameter of Neck

Post by scioly2 »

Hi everyone.

I am on my Science Olympiad team, and I am participating in the Bottle Rocket event. The instructions specifically say that the diameter of the bottle's neck must be 2.2 cm. However, many soda manufacturers have changed the standard size from 2.2 to 2.1, which will not launch from the Science Olympiad launchers. It fits too tightly on the apparatus.

Does anyone know of any manufacturers that still use the 2.2 size? If I cannot find this size, I cannot compete. Thanks.
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bugwubber
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Joined: Wed Dec 19, 2012 2:47 am

Re: Diameter of Neck

Post by bugwubber »

It varies by bottler, so basically by region. Not an issue in my region, but when I went to California, we found a number of them. If you can't find a suitable bottle by visiting different grocery stores, you may need to enlarge the neck opening either by reaming or gently heating while shoving a piece of pipe in the neck.
Bugwubber

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