Aero
11-09-2006, 05:45 PM
Hey everyone. You may have noticed that I havn't ben around much oover the past month or so. I havn't forgotten about everyone here, I've been alittle busy thats all.
Last year my friends and I started work on a Trebuchet. A Trebuchet is a device similar to a Catapault, except instead of storing energy in springs it uses a heavy weight. It started out as a small project, with plans calling for it being about 3 ft tall to maybe throw some stones across the neighbors yard....
Well..you see.. when you get 8 tenage boys togather with an idea...things start to grow. After a summer of talking we decided upon a machine 10 ft tall at the axle or pivot point of the arm. We build our machine and used approx 800 lbs of concrete as our weight. With our machine built we heard of the Morton IL Punkin Chuckin contest and figured why the hell not. So we drove the 4 hours down there and competed. We took 2nd the first day and 3rd the second. Our furthest shot was 394 ft.
We decided that this year we wanted that first place. So in August we broke the machine all the way down to the trailor it is built upon. We changed it from being a Trebuchet to a pure Catapault. We replace our wood boom (throwing arm) with a piece or cold rolled square tubular steel. The weight was replace with 10 garage door springs, each rated at 160 lbs of pull when fully extended. With this setup we again traveled to Morton IL this year. We again took second, but with a chuck of 673 ft, and our personal best unofficial shot being 693 ft.
So since we were having fun we said "Hey why stop now?" So we entered the Punkin Chunkin World Championship in Millsboro Delaware. We again change the design of the machine, adding a new spring mount to accomodate 20 garage door springs, totaling over 3000 lbs of pull.
So we called up school and were able to take off a few days for drive time. We drove the 850 miles there. One the first day we were almost disqualified because we didn't have a fire extinguisher or first aid kit (they have alot of crazy rules). We were luckly able to borrow one from the team next to us.
The way the Championship works is there are several divisions. We signed up for th Youth (11-17) Human Powered Catapault Division. Each team has 2 minutes to store the energy of one human in the machine.
We set the machine up with the 10 springs we used in Morton to makesure that everything was working good seeing as how we had never tested it with all the modifications. We were surprised to find we were able to throw only 424 ft. Another machine in our division was able to throw 692 ft the first day, so already we were behind.
We got it ready for the next day but with 16 springs this time. We wanted to slowly work upto the max of 20 to be sure we could still crank the winch in 2 minutes. When it came to our competition shot all was looking good. But then when we pulled the trigger the pumpkin flew amazingly, but so did the sling. And the rules state that if any part of the machine flys onto the field the distance must be taken from the piece, not the machine itself. Unfortunatly the sling was about 120 ft in the field, so our total distance was only 516 ft. But the shot to beat was still 692 ft.
So it all came down to the last shot on the last day. After a late night of calibrating the machine to release to pumpkin and setting it up we were able to get 2 test fires in. The first test fire went way high and only flew about 300 ft. The second shot exploded in the sling from the massive acceleration and landed about 50 ft behind us, almost hitting a food vendor tent. So we had to stop test firing for the competition. So we changed a few small things in hope of getting a straight shot. We had to just sit and wait for about 3 hours before the got to us. Talk about suspense. So we all back away and let the 2 members we elected for the final shot set it all up...
And then... they let it fly..
AND BOY DID IT FLY!!
At a near perfect 45 degree angle it just kept going. We could tell it was atleast a personal best. We knew we were the last in our Division to fire and needed to best 692 ft. We waited for about 2 minutes while the spotters reported the distance..
853.46 ft!
THATS RIGHT! We are now the world champions in the Youth devision. The only youth machine to beat us was an air cannon, but they are built by parents with sponsers and lots of money. We have a machine entirely designed, built, and paid for by teenagers. We think we may have even set the World Record for Youth Human Powered, but havn't been able to track down the offical previous record. I'm sorry I don't have any pics yet, my friend hasn't givin them to me yet. We also have about 3 hours of video that needs to be edited. I'll toss some pictures up when I can, but that about it for now.
Last year my friends and I started work on a Trebuchet. A Trebuchet is a device similar to a Catapault, except instead of storing energy in springs it uses a heavy weight. It started out as a small project, with plans calling for it being about 3 ft tall to maybe throw some stones across the neighbors yard....
Well..you see.. when you get 8 tenage boys togather with an idea...things start to grow. After a summer of talking we decided upon a machine 10 ft tall at the axle or pivot point of the arm. We build our machine and used approx 800 lbs of concrete as our weight. With our machine built we heard of the Morton IL Punkin Chuckin contest and figured why the hell not. So we drove the 4 hours down there and competed. We took 2nd the first day and 3rd the second. Our furthest shot was 394 ft.
We decided that this year we wanted that first place. So in August we broke the machine all the way down to the trailor it is built upon. We changed it from being a Trebuchet to a pure Catapault. We replace our wood boom (throwing arm) with a piece or cold rolled square tubular steel. The weight was replace with 10 garage door springs, each rated at 160 lbs of pull when fully extended. With this setup we again traveled to Morton IL this year. We again took second, but with a chuck of 673 ft, and our personal best unofficial shot being 693 ft.
So since we were having fun we said "Hey why stop now?" So we entered the Punkin Chunkin World Championship in Millsboro Delaware. We again change the design of the machine, adding a new spring mount to accomodate 20 garage door springs, totaling over 3000 lbs of pull.
So we called up school and were able to take off a few days for drive time. We drove the 850 miles there. One the first day we were almost disqualified because we didn't have a fire extinguisher or first aid kit (they have alot of crazy rules). We were luckly able to borrow one from the team next to us.
The way the Championship works is there are several divisions. We signed up for th Youth (11-17) Human Powered Catapault Division. Each team has 2 minutes to store the energy of one human in the machine.
We set the machine up with the 10 springs we used in Morton to makesure that everything was working good seeing as how we had never tested it with all the modifications. We were surprised to find we were able to throw only 424 ft. Another machine in our division was able to throw 692 ft the first day, so already we were behind.
We got it ready for the next day but with 16 springs this time. We wanted to slowly work upto the max of 20 to be sure we could still crank the winch in 2 minutes. When it came to our competition shot all was looking good. But then when we pulled the trigger the pumpkin flew amazingly, but so did the sling. And the rules state that if any part of the machine flys onto the field the distance must be taken from the piece, not the machine itself. Unfortunatly the sling was about 120 ft in the field, so our total distance was only 516 ft. But the shot to beat was still 692 ft.
So it all came down to the last shot on the last day. After a late night of calibrating the machine to release to pumpkin and setting it up we were able to get 2 test fires in. The first test fire went way high and only flew about 300 ft. The second shot exploded in the sling from the massive acceleration and landed about 50 ft behind us, almost hitting a food vendor tent. So we had to stop test firing for the competition. So we changed a few small things in hope of getting a straight shot. We had to just sit and wait for about 3 hours before the got to us. Talk about suspense. So we all back away and let the 2 members we elected for the final shot set it all up...
And then... they let it fly..
AND BOY DID IT FLY!!
At a near perfect 45 degree angle it just kept going. We could tell it was atleast a personal best. We knew we were the last in our Division to fire and needed to best 692 ft. We waited for about 2 minutes while the spotters reported the distance..
853.46 ft!
THATS RIGHT! We are now the world champions in the Youth devision. The only youth machine to beat us was an air cannon, but they are built by parents with sponsers and lots of money. We have a machine entirely designed, built, and paid for by teenagers. We think we may have even set the World Record for Youth Human Powered, but havn't been able to track down the offical previous record. I'm sorry I don't have any pics yet, my friend hasn't givin them to me yet. We also have about 3 hours of video that needs to be edited. I'll toss some pictures up when I can, but that about it for now.