From Gray Co. Trebuchet Page
Stone Carving of a traction trebuchet throwing a carcass.
Dedicated to my new son Trevor born Oct 16th, 1999
Eric Have you ever wondered why, boulders never cross the sky? You can heave with all your might, boulders never will take flight. but here's a trick that you can do, to chunk a rock to Timbucktu. `A Catapult' as some might say, but be correct, it's `treb-u-chet.' Trevor I will not build this `treb-u-chet' I will not, shall not waste my day I shall not build it out of wood, I shall not build it, it's no good. Eric How can you think that it's no good? the trebuchet's misunderstood! You can fling a rock real far you can even fling a car. You can fling it through the woods thus I say that it is good. Trevor This trebuchet that's built of wood which you claim's misunderstood, Who would build it, please do say who would build this `treb-u-chet'?
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From Gray Co. Trebuchet Page Stone Carving of a traction trebuchet throwing a carcass. |
Eric The `trebuchet' from ancient years were built by Roman engineers. They could build them out of wood Near them castles fell, not stood. They could fling a giant rock, They could fling it in a sock. With them empires they did build and conquered towns where they willed They could build a `treb-u-chet', They could build it, so I say. Trevor This `trebuchet' has me vexed for it seems to me complex. With gyres and gimbles long and short and rocks a flying with retort Flying rocks did ricochet who else built a `treb-u-chet?'
Monty Python & The Holy Grail: "You stoo-pid Ka-Niggits!" |
Eric Medieval Frenchmen taunting kings They sure knew what to fling. Cats and dogs, pig and sow They would even fling a cow Knights in fear did "Run Away!" When frenchmen used the `treb-u-chet.' Trevor Medieval Frenchman fling a cow? For this purpose tell me how. Cow flinging may sound cliché how do you build a `treb-u-chet?' Eric To fling a cow, so it's said, you must find one that is dead. Dead cows are so much less crass Living cows would kick your ass. Trevor Dead or living I do not care I want to fling one fair and square. Let us build this `treb-u-chet' Let us build it now I say
Juggernaut 2 is laid out for assembly. |
Eric To build this structure we need tools drill and hammer, wrench and spool.
Roger packs Juggernaut 2 into his truck. |
For lots of lumber we must go make a trip to Home Depot. Gyres and gimbles, bolts and beams fulcrums, triggers, and big dreams Trevor With all these things there is no way that you could build a `treb-u-chet'. What is this bolt marked F-2 what on earth could this thing do? Eric Every piece's job is set no more pieces need we get. F-2 is important true, but so are all these screws and glue. To build a frame that is quite tall, to fling a cow across a wall, Geometry will tell us how to make a frame, and throw a cow. Trevor Geometry! My fate is sealed, classroom wounds have not yet healed. Triangles are bent obtuse strangled by hi-pot-a-noose. I cannot build the numbered way I cannot build this `treb-u-chet' Eric Numbers Shmumbers it's O.K. You can build this `treb-u-chet' Please remember this simple rule Geometry is just a tool
On Site Assembly of the System. |
A strong foundation you do need it's most important so take heed. A frame is first, I don't care how it must be tall and hold your cow. Triangles here without delay, We do not want to swing and sway. Nuts and bolts, make sure they're tight we need to keep these posts upright. Trevor Now I've built it tall and strong, but I profess; it does seem wrong. Looking here I can't see how It can be used to throw a cow. All this lumber could betray I do not trust this `treb-u-chet'. Eric Woah there fella, do not fret Your trebuchet is not done yet! Grab that pipe there named F-1 That will be a great fulcrum
Roger Carries the arm. |
And let us use this mighty tree, Label it L-1, 2 and 3. The lengths here are quite a mix a ratio of 1 to 6. In L-1 cut a hole like this A fulcrum pivot cannot miss. No not there! Right here will do right between L-3 and 2. Trevor Your ratio drives me to distress I do not get it, I confess!Looking here I can't see how It can be used to throw a cow. Killing trees leads to dismay I cannot build this `treb-u-chet'. Eric Hang on buddy, you're almost done and will be flinging just for fun. Next we need a counterweight and to hold it, a giant crate. How much it weighs, let me see You're cow here weighs 3-0-3 A ratio of 600 to 1 Oh my goodness, it's 90 ton! Trevor 90 ton does not seem good this large frame is made of wood. Looking here I can't see how It can be used to throw a cow.
Our Weight Crate with 600lbs in it. |
Giant boulders that are gray will now crush this `treb-u-chet'. Eric Well now, let us readjust, a new ratio is a must. If now I say 60 to 1 our new mass is but 9 ton. There's no need to be exact lets see how this treb reacts.
Loading in counterweight. |
Now L-2 is too short Lengthen it to gain support. The weight must hang a length L-4 with fulcrum F-2 at its core. Now the arm points straight up, there's one more thing to hookup. Trevor The cow, the cow, throw it's core before it decomposes more Eric Patience friend, the cow is last At this time we must haul our mast. For heave you may, and heave you might the Arm has gained far too much height. Pulling weight into the air requires some tough hard-a-ware. A pulley labeled 1 to 8, Surely it can loft that crate.
Roger winches back the arm. |
The sliding draw down mechanism. |
And hook it to a sliding thing We'll do it with this burly ring. Finish with the mighty winch to haul up rocks it is a cinch. Trevor Just a minute, stop right there hauling rocks into the air. These poor rocks are scared of heights you have given them quite a fright. I must call the S.P.C.A I shall not build this `treb-u-chet'. Eric Well now, be that as it may, We will finish our trebuchet. Look real close now at this figure, that is how you build a trigger.
Our toothy wheel trigger mechanism. |
Sling to arm ratio example. |
Add a lever and wheel with teeth loop some rope down just beneath. Now detach our draw down line and hope our trigger is benign. Trevor Your trebuchet does seem weak bolts are bending, pivots squeak. I do fear some foul play I shall not use this `treb-u-chet'. Eric First let's tie a mighty sling Here a bowlin, there a ring We'll measure it against the tree our length this time will match L-3 The length is special beam to sling then back again to our ring. Tie it on right near the end and now we need a hook my friend. Trevor This sling-ring-thing is so strange will it throw our cow down range? Should our cow fall to decay I cannot use this `treb-u-chet' Eric Do not fear your rotting friend, now our project is near its end Crank the lever arm down low not so fast, it is quite slow.
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The ring and hook. |
Bolt this hook upon the arm and to you will come no harm. Place this ring upon the hook the cow is nestled in it's nook. Now the event for which you waited; release the arm and be elated. Trevor I cannot, shall not throw this cow, I must profess I don't know how. Your gyres and gimbles do confuse Your ratios do cows abuse I cannot launch your `treb-u-chet' I cannot, will not go astray.
Ready to throw a gallon of water. |
Eric But this trebuchet, it is complete In castle siege, we can defeat Our weight is lofted, bolts did fix the cow is ready to deep six You must launch without delay you must launch this `treb-u-chet' Trevor Ok, maybe just this one time I'll push here to launch some slime.
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| Launching a gallon of water. | |||
Oh my goodness, watch it go over rooftops, into Stow*. I think I like it, so I say I think I like this `treb-u-chet'
Credits:
Footnotes:
Details:
Our trebuchet is 8' tall, and uses a 550lb counterweight.
Our weight ratio is about 60 to 1
Our best throw to date is 299 feet at the World Championship
Punkin' Chunk with a 9 lbs pumpkin.
We never bothered calculating what L2, L3, & L4 are.
Copyright (C) November 1999, 2000, 2001 Eric M. Ludlam. All rights reserved.
Unauthorized duplication and distribution of this page is strictly prohibited.
Twas' brillig, and the slithy toves did gyre and gimble in the wabe.