Team Big Bertha

[Flight School Capt]

I figured since this is the air cannon forum, I can ask you all specifically since you all will know better than other groups (if its in the wrong section, I appologize).

I watched the show on the Science Channel and then brought together three other people from my school (yes we are going to grow to about six members max) to build a cannon as well. We figured that it looked fun and, since it is for charity, it would be a good deed.

Problem is, although we designed the cannon, we don't know where to get parts and otherwise. We decided it to be a 125 foot long barrel with three tanks to fill with compressed air, but we don't know the average size of those tanks. We know that it will cost us alot, but were ready to take on costs.

I'd like to ask you all a few questions while this thread is made:

• Is there a team known as Big Bertha already made? If so, we will simply change our name. Easy fix-up.
• Where do we register to be a new team, but not register to be in the competition? I want to reserve our name so we dont have to go through our in-team voting process again ) but we won't have our cannon ready for a few years as it is very big and we are nearly finished with high school.
• Just out of curiousity, if you would like to share some basic (I don't want to steal your cannon's dimensions ) information regarding the construction of your cannon, that would be great
• What are some companies that you bought things like valves, cannon barrel parts, and pumpkins? I fully intend on following all the rules, I just need help finding out where to get those specialized parts.

[themetknack]

Hello and welcome to the chunkin form

I will try to answer as many question that I can. Parts: Barrel has to be made from either aluminum or steel, and seeing that you are trying to go 125 feet I would recommend aluminum, I use a 8 inch barrel for my air cannon, but most people use 10 inches. It is hard to find a pumpkin to fit 8 inches that weighs 8 or more pounds, but it allow less air to blow by. For a rule of thumb I use a 7 to 1 ratio of tank to barrel. My tank is about 700 gals and the barrel is about 100 gals. About the name, there is no air cannon named Big Bertha, not sure about the trebs and other stuff, you could look down last years list of machines that are online. You register machine when you are ready to chunk. New machine can register to get into the chunk after June 1st with a limit of 100 machine and about 30 air cannons, and it fills up quickly each year. For valves I and most other people use what is called a butterfly valve which you can find in McMaster Carr and MSC are a few place you can find them. In regard to a tank I got mine from M & M Refrigeration in Maryland, not from the chunkin field. Mr. Duffy is who you will have to talk to, I do not remember his last name. Where a you located? Mr. Duffy usually show up the the membership meeting here in Delaware. Also on a side note, bigger is not always better Mr. Duffy has Fire and Ice which has a 152 foot long barrel and a huge tank, like 10,000 gals, and still his best placement was third, and he has been chunkin for 4 years and has put some money into it. On the other hand, there are smaller cannons that shoot farther then him. By the way I am the captain of Ozone Blaster and it is for sale if you want to get in.

[Flight School Capt]

Very interesting. I'll look into those places.

I saw your post about Ozone Blaster, and, although it looks good based on what it has goten in the past, my team and I want to take pride in building our own machine. If you would like to help by giving us information here and there about how to build it and everything, that would be awesome.

Our barrel is going to be a 10" or an 11" barrel to make sure that our pumpkin doesn't pie or scrape. That would be baaaaaaaaad

Location is Kentucky. Obviously a bit far away, but I want to go off to the US Air Force Academy so that I can minor in aeronautical engineering (to make a better cannon) and to be stationed up near New England.

Do you have any site URL's for parts or phone numbers?

[themetknack]

That cool that your are going for Aeronautical Engineering, I am in Mechanical Engineering at a local college. Good luck on finding 11 inch pipe, but 10 inches is enough. With the valves, you can get ones with air rams on then, but we just pulled off the handle off and put our own air ram on it. In the way of pumpkins we just go to the local farmer. The only rules are must weigh 8 to 10 pounds and have to be left in the original state, no alternating the pumpkin. Another thing about air cannons is the air pressure most cannon only run about
150 psi, the issue is that the pumpkin is so close to the sound barrier that it can not handle the energy to close the barrier which is what can cause pie. More often then not the pumpkin is getting hit to hard with the air. I will try to get some phone numbers. Let me know what else you are looking for.

Michael

Here is a few URL
McMaster Carr Butterfly Valves the largest is 8 inch http://www.mcmaster.com/#butterfly-valves/=5nwkn3
MSC Butterfly Valves the largest is 10 inch http://www1.mscdirect.com/CGI/GSDRVSM?PACACHE=000000125598312

[Flight School Capt]

Sweet. Thanks.

It is never as easy as "Stick pipe on tank - Check", so it is good to have a person who has experience to help.


Yeah. I wanted a 10"-11" barrel so there is less of a risk to pie, but if you recommend smaller, we will take that into consideration heavily.

[Flight School Capt]

Were going the route of a smaller cannon. Which means our name changes to Flight School too.

65 foot barrel with one tank is good? Or would you recommend longer?

[themetknack]

That sound more reasonable. If your are going with a 65 foot barrel and a single tank. The tank will need to be 1800 gallons if you want to maintain a 7 to 1 ratio of tank to barrel. Which is not bad, but what might help is getting two tanks, 1000 gals a piece and do two stages like the Great Emancipator, which shoots good when they can get their timing down. Another cannon that is about that size is Young Glory III and their tank is about 1500 gals and they took first in 2008 and set the world record. Good luck.

[Assoc Pres]

It is VERY important you understand you must either use unaltered ASME tanks with the name plate data attached or have tanks custom made. Neither are cheap.
You may not use DOT propane type tanks and you may not alter an existing tank in anyway. All ASME tanks have drawings which are on record with the national board and validated for alterations before entering.

Hate to see you waste money on a tank you can not use!
John