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Thread: Looking to build a catapult/trebuchet

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    Question Looking to build a catapult/trebuchet

    Not sure if this is the right area, but I got the permission from my wife to construct a trebuchet/catapult to play with in the desert.

    My plans are to build one what can ultimately hurl baseballs/softballs a few hundred yard.

    I want it to be big, but not huge although i think I may need a trailer to haul it..

    Does anyone have any experience with builds like this? Has anyone done one before?
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    Google gave me pages and pages of links to designs and organizations from historical to pumpkin chucking.
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    Check on the graybeardoutdoors.com forums and I believe that the have the very forum you seek.Frank

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    http://hubpages.com/hub/trebuchetplansfree for basic dimensional and weight ratios. The bigger the trebuchet the heavier the projectile and the further it will go.

    Also, trebuchets throw further and more accurately if mounted on wheels which take out the recoil without tilting the whole machine forward.

    See http://www.allbusiness.com/professio.../422775-1.html for an engineering approach to the Trebuchet. A 20.5 foot beam and one ton counterweight will throw a bowling ball 150 yards.
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    We built a ballista back when I was in high school, in West Texas in the 1960s. It used a welded steel box frame with torsion skeins of oil field cable, and arms made out of a pair of truck axles. It would toss a one pound coffee can full of concrete for about four hundred yards.
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    Quote Originally Posted by Optimist View Post
    We built a ballista back when I was in high school, in West Texas in the 1960s. It used a welded steel box frame with torsion skeins of oil field cable, and arms made out of a pair of truck axles. It would toss a one pound coffee can full of concrete for about four hundred yards.
    NICE! i taught art for a year and one project was having the kids build them out of popsicle sticks and then compete tossing paint balls.

    As of right now, i am thinking of making a scaled down version so i can work out the bugs before building the big one.......
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    I made one with a pony keg for a counterweight. I hung it by the tap with an adapter I machined.

    I didn't get the sling right so it was a failure but I think the keg weight was a good idea.

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    Neighbor kids stretched several lengths of gum rubber tubing between the patio roof posts & attached a canvas swing seat in the middle. It took 2 of them to pull it back, but would hurl an impressive load of dog poo over the neighbors' house, across the street & into the park where a softball tournament was in progress.

    Consider, too, the lowly potato gun. Neighbors on the other side of me gave me one to disassemble - they wanted the ignition back for their gas BBQ. One of the kids got carless & fired a spud clear thru the metal side door to their garage - just missed one of the kids - woulda' gone clear thru him & left a hole you could see thru.

    Another neighbor built a golfball launcher - propane powered & an adaptation of the noisemaking canons once used at the nearby airport to scare off birds on the runway. He said they could blast a golf ball thru a 10" stack of newspapers. Never got to see it in action.

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    Quote Originally Posted by AZshooter View Post
    Neighbor kids stretched several lengths of gum rubber tubing between the patio roof posts & attached a canvas swing seat in the middle. It took 2 of them to pull it back, but would hurl an impressive load of dog poo over the neighbors' house, across the street & into the park where a softball tournament was in progress.

    Consider, too, the lowly potato gun. Neighbors on the other side of me gave me one to disassemble - they wanted the ignition back for their gas BBQ. One of the kids got carless & fired a spud clear thru the metal side door to their garage - just missed one of the kids - woulda' gone clear thru him & left a hole you could see thru.

    Another neighbor built a golfball launcher - propane powered & an adaptation of the noisemaking canons once used at the nearby airport to scare off birds on the runway. He said they could blast a golf ball thru a 10" stack of newspapers. Never got to see it in action.
    my brother and used to hurl dog crap with ordinary shovels...but our range was 50 feet tops
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    Quote Originally Posted by wash View Post
    I made one with a pony keg for a counterweight. I hung it by the tap with an adapter I machined.

    I didn't get the sling right so it was a failure but I think the keg weight was a good idea.
    You need to get the dimensional and weight ratios correct. Once those are set up the bigger it gets the more it can throw and the more efficient it is up to the material limits.
    I swear by Jupiter Optimus Maximus .... in the army of the consul Lucius Quinctius Cincinnatus and for 10 miles around it I will not steal anything worth more than a sestertius in any one day.

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    Quote Originally Posted by AZshooter View Post
    Neighbor kids stretched several lengths of gum rubber tubing between the patio roof posts & attached a canvas swing seat in the middle. It took 2 of them to pull it back, but would hurl an impressive load of dog poo over the neighbors' house, across the street & into the park where a softball tournament was in progress.

    Consider, too, the lowly potato gun. Neighbors on the other side of me gave me one to disassemble - they wanted the ignition back for their gas BBQ. One of the kids got carless & fired a spud clear thru the metal side door to their garage - just missed one of the kids - woulda' gone clear thru him & left a hole you could see thru.

    Another neighbor built a golfball launcher - propane powered & an adaptation of the noisemaking canons once used at the nearby airport to scare off birds on the runway. He said they could blast a golf ball thru a 10" stack of newspapers. Never got to see it in action
    .
    BATFE has some comments about potato guns - under some circumstances treats them then like Destructive Devices and demands considerable penalties for making or possessing one without first doing suitable paperwork and paying money. I suspect the golf ball flinger would attract their attention if they happened to hear about it.
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    Quote Originally Posted by Clyde View Post
    BATFE has some comments about potato guns - under some circumstances treats them then like Destructive Devices and demands considerable penalties for making or possessing one without first doing suitable paperwork and paying money. I suspect the golf ball flinger would attract their attention if they happened to hear about it.
    do you have a source for these 'comments'?
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    Quote Originally Posted by requiem View Post
    do you have a source for these 'comments'?
    Last ones i saw were on ATFE's web-site. Basically, if not designed or intended as a weapon, they will not look very hard and say it is OK. But - an example that would punch through a metal door with a potato or punch though a 10" stack of newspapers with a golf ball might (if they got wind of it) tend to make them question a claim it wasn't designed as a weapon. You do not want them asking that sort of question of you can help it.
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    Quote Originally Posted by requiem View Post
    do you have a source for these 'comments'?
    The ATF!
    Federal law is easy as you will see from the links below. State and local ordinances you are on your own.
    People get confused because the ATF website FAQ has an answer about getting a spud-gun classified. You don't need to get one classified. If it is intended for recreational use shooting potatos and not for use as a weapon, it is legal. I've listed two references, first the ATF FAQ which doesn't tell you it's a weapon, firearm, or destructive device. It just tells how to get one classified. If you were going to sell them, it might be a good idea to do so. The second is from a letter from ATF posted on the SpudFiles website. It says a spud gun is not a firearm if used recreationally to shoot potatos. It is a regulated device if intended to be a weapon or shoot exploding devices etc.
    From the ATF website FAQ: http://forum.pafoa.org/general-2/392...otato-gun.html
    Q: How do I obtain a classification from ATF for my “potato gun?”Any person desiring a classification of a “potato gun,” “spud gun” or similar device must submit a written request (not e-mail) to the Director and include a complete and accurate description of the device, the name and address of the manufacturer or importer, the purpose for which it is intended, and such photographs, diagrams, or drawings as may be necessary to make a classification. A final determination may require physical examination of the device. Such requests for classification should be submitted to: Bureau of ATF, Firearms Technology Branch.

    http://www.spudfiles.com/spud_wiki/i...r_from_the_ATF
    ..."We have previously examined that certain muzzle loading devices known as "potato guns." These potato guns are constructed from PVC plastic tubing. They use hair spray or a similar aerosol substance for a propellant, and have some type of spark ignitor. We have determined that these devices, as described, are not firearms provided that they are used solely for launching potatoes for recreational purposes. However, any such devices which are used as weapons or used to launch other forms of projectiles may be firearms and destructive devices as defined."
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    Spud guns are different in that they do use an explosion for propulsion and may possibly be considered a firearm if designed and used as "destructive devices". Catapults and trebuchets are no more firearms than a bow or sling.
    I swear by Jupiter Optimus Maximus .... in the army of the consul Lucius Quinctius Cincinnatus and for 10 miles around it I will not steal anything worth more than a sestertius in any one day.

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    Quote Originally Posted by jjk308 View Post
    Spud guns are different in that they do use an explosion for propulsion and may possibly be considered a firearm if designed and used as "destructive devices". Catapults and trebuchets are no more firearms than a bow or sling.
    so i could hurl pork at a mosque and get away with it - nice! j/k

    i did some research on spud guns and this i will give one a shot just to entertain my ADHD.
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    Quote Originally Posted by Ordtech View Post
    The ATF!
    Federal law is easy as you will see from the links below. State and local ordinances you are on your own.
    People get confused because the ATF website FAQ has an answer about getting a spud-gun classified. You don't need to get one classified. If it is intended for recreational use shooting potatos and not for use as a weapon, it is legal. I've listed two references, first the ATF FAQ which doesn't tell you it's a weapon, firearm, or destructive device. It just tells how to get one classified. If you were going to sell them, it might be a good idea to do so. The second is from a letter from ATF posted on the SpudFiles website. It says a spud gun is not a firearm if used recreationally to shoot potatos. It is a regulated device if intended to be a weapon or shoot exploding devices etc.
    From the ATF website FAQ: http://forum.pafoa.org/general-2/392...otato-gun.html
    Q: How do I obtain a classification from ATF for my “potato gun?”Any person desiring a classification of a “potato gun,” “spud gun” or similar device must submit a written request (not e-mail) to the Director and include a complete and accurate description of the device, the name and address of the manufacturer or importer, the purpose for which it is intended, and such photographs, diagrams, or drawings as may be necessary to make a classification. A final determination may require physical examination of the device. Such requests for classification should be submitted to: Bureau of ATF, Firearms Technology Branch.

    http://www.spudfiles.com/spud_wiki/i...r_from_the_ATF
    ..."We have previously examined that certain muzzle loading devices known as "potato guns." These potato guns are constructed from PVC plastic tubing. They use hair spray or a similar aerosol substance for a propellant, and have some type of spark ignitor. We have determined that these devices, as described, are not firearms provided that they are used solely for launching potatoes for recreational purposes. However, any such devices which are used as weapons or used to launch other forms of projectiles may be firearms and destructive devices as defined."
    That "other forms of projectiles" should make the golf ball shooters - nervous.
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    Quote Originally Posted by requiem View Post
    so i could hurl pork at a mosque and get away with it - nice! j/k

    i did some research on spud guns and this i will give one a shot just to entertain my ADHD.
    Need a big one and use it hurl hog carcases - ripe ones...

    We have plenty of feral hogs down here that could be used to supply the ammo. Or if you were feeling really evil, could trap them and keep the boars alive and throw them, with whatever you use to truss them for the shoot weakened enough that they could get loose after landing. Any that were not killed would be - ugly customers for the followers of Mohammed (or whoever else you delivered them to) to deal with.
    Absent comrades (sound of breaking glass)

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    How about a spud gun that shoots... SPAM!

    I have plans on PDF for a table top trebuchet made of card stock. Pretty neat for hurling grapes or Chi hua hua poop. If anyone is interested send me a PM.

    I've seen big ones hurling refrigerators and cars. There was a guy in Merry ole England hurling people into a lake until it didn't unhook just right and one lady got planted in the ground...
    "When bad men combine, the good must associate; else they will fall one by one, an unpitied sacrifice in a contemptible struggle."
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    Look into one of my professors from the Virginia Miiltary Institute, Col Wayne Neel. He was my drafting/CAD professor. He was featured on NOVA with building a couple of types of trebuchets. He would drag them out of storage every hear and launch beer kegs.

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    Quote Originally Posted by Clyde View Post
    BATFE has some comments about potato guns - under some circumstances treats them then like Destructive Devices and demands considerable penalties for making or possessing one without first doing suitable paperwork and paying money. I suspect the golf ball flinger would attract their attention if they happened to hear about it.
    No worries. The neighbors moved away a couple of years ago & doubtful the hairspray residue in the disassembled tubing, or any PVC crumbs in the hacksaw teeth could lead to anything conclusive. Never followed up with the golfball guys, but at one time an on-line vendor (Cheaper Than Dirt or Tapco-type place) manufactured several "salute" cannons. One specified a bore diameter that just happened to be suitable for golf balls, although the retail write-up was painstakingly careful to NOT mention the product & the sports item in their ads.

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