Bottle Rocket B

[space scientist]

What launchers will be used at the competition?

The most common launcher that you will see is the Aquaport one that was previously mentioned on this thread, but you may occasionally see other types of launchers (like the NERDS one that was previously mentioned on this thread or a homemade launcher).

On a side note, do you go to Woodcreek Junior High School (I want to know what active members on the board are in the same school as me.)?

[jma]

Is the bottle neck opening internal of the 1 litter smaller than the 2 litter? Does anyone have any problem of fitting the 1 litter into the launcher? I used the homemade one and the 2 litter fit perfectly but the 1 litter doesn't. I can fix my launcher but I just want to make sure I don't have the same problem on the competition day. I used the safeway cola and fruit flavor sparkling water bottle.

[Saturiea]

Nozzle size is extremely variable between bottles. So sticking to the 2.2cm opening specified by the rules is best. Get a set of calibers to check the inside diameter and if it is not 2.2cm don't use it. The variability is strong between bottles, for example Dr. Pepper work, but Diet Dr. Pepper are a bit too small. So just check before you build with a set of calibers

[jma]

Thank you Saturiea. I will get a set of calibers.

[Glopy19]

What launchers will be used at the competition?

The most common launcher that you will see is the Aquaport one that was previously mentioned on this thread, but you may occasionally see other types of launchers (like the NERDS one that was previously mentioned on this thread or a homemade launcher).

On a side note, do you go to Woodcreek Junior High School (I want to know what active members on the board are in the same school as me.)?

I go to Colleyville Middle school.

[jma]

So far, I had no luck in finding a 1 litter bottle with a 2.2 nozzle. All the bottles I got had 2.16 in nozzle size. Can someone kindly tell me the brand if you already found one? Thanks.

[fleet130]

the 2 litter fit perfectly but the 1 litter doesn't

I had no luck in finding a 1 litter bottle with a 2.2 nozzle. All the bottles I got had 2.16 in nozzle size

A 2.16 cm nozzle inside diameter should fulfill the "approximately 2.2 cm" requirement stated in the rules. Others may be able to shed more light on whether it will/will not fit on any given launcher.

The 2.2 cm statement was originally added to differentiate acceptable bottles from those with larger openings (3 or maybe even 4 cm) commonly distributed in some ares of the country. Exact inside diameter of the opening varies considerably from bottle to bottle and even more between manufacturers.

Five or six years ago we researched dimensions/tolerances of the various launchers and bottles and came to the conclusion that, if a piece of 1/2 inch PVC pipe just fit into the bottle opening (1/2 inch PVC pipe has an outside diameter of 0.840 inches +/- 0.001 inch), the bottle would fit on all (most?) commercial launchers available at that time. This may not/may not be true for launchers sold today.

[sciencechic]

Go to a store and get a bunch of bottles, then test them all. This is how we found the best bottle. We just launched the bottles for time and found the best launcher.
National times should be close to 25+ seconds this year.... jmho....

[KKForever5]

Anybody have a good fin design? BTW I'm new here.

[fishman100]

Anybody have a good fin design? BTW I'm new here.

The Image Gallery has some pretty good shots of different fin designs that you might want to test. Look on different websites; there are also some designs that my partner and I found to be effective.