item 2 of 7 for this year's state fair

Dan Noren

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while trying to figure out what kind of toy to make, i happened upon a set of plans for a small trebuchet. it will be fun to see what kind of range this thing will have.
 

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Judging by the size of the pieces that trebuchet is a bit bigger for a toy, so its range and power should be rather high. Are you planning to assault some castle?
 
just some place in spain toni, but mainly on the plain. opened up the shop today and did the cutting of the parts for the trebuchet. tomorrow i will be making the finesse cuts and drilling the necessary holes for the pivot pins and other attachments. i've also included a pic of the final design for the trebuchet.
 

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Is that trough in the SketchUp to be used to carry off the water in case you scare it out of someone?

Have fun throwing rocks, corn puffs, marshmellows, grapes or whatevers.

Enjoy,
JimB

Nah! You can't throw rocks. You might scratch that pretty thing---stick with corn puffs or ping pong balls.
 
picked up the aluminium rod for the pivot pins, string for the sling, and material for the pouch today. jim, i was originally thinking about using golf balls, but they were too big. then i thought about using the .69 caliber round balls that i use in my black powder shotgun, but then i thought that might not be a good idea (costs of glass replacement and possible injuries downrange you know). then i hit on a happy solution, .68 caliber paintballs. perfect counterweight to projectile weight ratio (they recommend a 5:1 ratio, but with a paintball weight of roughly .11 ounces, and a counterweight of 40 ounces (that's 2.5 lbs, not a large bottle of beer) that works out to about a 362:1 ratio. that should be enough to get some good distance and airtime. nice thing about a paintball is they don't bounce when they hit, and it will be easy to step off the travelled distance. mind you now, i did buy a sufficient amount (smaller bags were not available) to allow me a few practice lobs.
 

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The paint ball look to be the perfect size. I doubt they will break though. I believe that they need velocity that the trebuchet wont give.
The one I made a few years ago was about the same size and it would lob a grape about 20 feet.
 
Darn you make me miss the fair. We have a good county fair. My kids use to show sheep and sell them each year at the fair. It was a great time with 4H, well except for the day they had to say good-bye to their sheep as they were loaded on a truck to go to the slaughter house! Part of life's lessons. I have thought of putting some of my project in the fair but I never quite get to it.
 
well, got all of the half laps and dadoes cut, and all of the axle holes drilled. in doing the second mock up, i found that i need to redo the counterweight box (it will hold about 4 lbs of lead .451 round balls), shorten up the guide supports, and cut a slightly longer axle for the counterweight box. all in all, it worked as well as i had expected. after the quick fixes, it will be time to add the release hardware, and the sling and it's hardware. then it will be on to live fire testing.... :D:thumb:
 

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busy day today. fixed the guide supports, and cut the new axle for the counterweight basket. tomorrow the work commences on the new counterweight basket.
 

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fixed the problem with the counterweight basket, and assembled the new one. also assembled the throwing arm to test the assembled parts (4 lbs of lead really makes it move). found another part to fix, the guide is a bit too high, and i will have to take a touch off of the boards for that.
 

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not letting the dinged finger slow me down on this one. sanded all of the parts and started the final assembly of the structure. now all that is left is some final sanding and such, adding the hardware and sling, a coat of blo, and its off to the firing tests. :thumb:
 

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figured out and rigged the trigger. also glued the guide in place. i'll have to plane the top edges down a touch, as they are making contact with the bottom of the counterweight basket. i have included a video of a test release. sorry, no projectile this time....
 

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