Well, I just completed a physics project, in which I built a fully-functional trebuchet [wow, that isn't in Firefox's dictionary] in about 18 hours. It stands roughly 4.5 feet tall, and I have no idea how far, or how much, it can fling. It's rather narrow [hence not knowing the maximum counterbalance weight or projectile weight], inefficient [no wheels, poor hole angles, etc.] so I'm going to revamp it. Here's the original trebuchet plans. If you look at it, you'll notice I wasn't kidding about the narrowness.

My next project, which I am not in any rush to do, I will have an arm over 10 feet tall, and it should be able to throw stuffs much, much better. Plans are going to be based off of my own designs, which I'll figure out later, based off of the highest simulated efficiency. Your thoughts, SEN?

Post has been edited 1 time(s), last time on Jan 30 2010, 6:22 am by poison_us.

Make a fireball launcher like I did.

How big is that, exactly?

It's not at all big. I made it kind of "portable". It actually is more like a fireball gun and not really omggawdrocketlaunchersize big.
And it's nothing as fancy as your trebuchet. The one I did was a "test" model. I improvised it with a kitchen paper-towel's tube and a toilet paper tube


Also, awesome, you did a really good job with the plans and everything else, out of curiosity, where did you make them?

Thanks for the "fancy", but it's not superneat, nor super-nice looking. I actually had to grind the crap outta three or four spots just to get the counterbalance to not hit a leg. It shoots maybe 30 feet, when it's supposed to do over 100 with a similar object...but then again, 18 hours, 4ish of which were spent finding wood without knots, and 2ish spent driving. I'll have pix tomorrow or something, just to show you how gross it looks.

The .pdf? I found it on the Interbutt

EDIT: I'll have pix before 9:20



Post has been edited 2 time(s), last time on Jan 25 2010, 2:24 am by poison_us. Reason: PIX ZOMG!

This masterpiece won me a notebook. Goal was to build a trebuchet which could hit a target 20 feet away. We hit it on the first shot.

I thought you had done the pdf yourself too

I has been fooled

My fireball launcher goes to 9'' at exactly 45° . and I wouldn't want it defending my life unless the other person is showered in gasoline

Post has been edited 1 time(s), last time on Jan 25 2010, 5:26 am by Corbo.

Lol. What do you mean "45%"? He meant degrees
BTW, I found a nice site that has approximate relations for everything. It's even got it in notation for a simulator I already had downloaded.

Based off of the site's functions, I should have:

• 2.5' on the CW side of the throwing arm
  
• 7.5' on the opposite side of the same arm
  
• 7.5' tether (holding the sling & projectile)
  
• 2.819' (roughly 33.83") CW hanger
  
• 5.319' (roughly 63.83") axle struts
  
• Total length: 25.638'
  
• Simulator test: 552.1' range, 277.1' height, .65 Reff^*, .69 RGeff^*
  

^*Reff = efficiency from the counterweight alone. RGeff factors in the main beam as well. The efficiency is the "ideal range" divided by the resultant range. "ideal range is 2*h*m1/m2", where h is how far the counterweight can fall.

Of course, all these are gonna be changed because I can probably tweak it to get a couple more feet. I plan on posting the Excel book I'm doing this in whenever I've completed the trebuchet.

---

Update: Best [theoretically] achievable distance with about 10' of throwing arm found!

• Not posting the individual lengths, just because. They'll get put up eventually.
  
• Total length: 27.875'
  
• Simulator test: 661.7' range, 323.5' height, .69 Reff^*, .74 RGeff^*
  

^*See above.

By tweaking the numbers, I managed to pump out .04 or .05% more efficiency (considering some had over +.1%, but less range, I'm willing to deal with this). Also, it produced 46.4 feet of additional height (ok, great, who cares), and over 100 more feet of distance (now we're talking )
So for about 2 additional feet of tree, and 1/8^th inch extra twine, I get more efficient, higher, and farther. Sounds like a bargain, right?

Ok, I'll admit: I didn't mess with the weights themselves, because I can't measure the beam weight when I don't have the beam They stayed at a constant 800 lbs for the counterweight, 8 for the projectile, and 54 for the main beam. I honestly doubt I'll have 800 lbs as a counterweight, needless to say. I sorta need to figure out how much the beam will weigh to do any accurate stuffs with the weights.

Post has been edited 1 time(s), last time on Jan 25 2010, 6:43 am by poison_us.

I sooo love military stuff. When I was about 15, long after I stopped playing my lego, I decided to remember the good old days and built a trebuchet. I didn't use tissue to hold the projectile, but a hook. The entire thing was purely lego except the hook itself, which needed a piece off a metal hanger (hanger for clothes) and a bit of glue. The projectile was an AAA battery with a lego grip for the hook glued to it. The weight on the other end was a lego battery block for the electro engine. Because it was so hard to get the release working right, the range was limited to about a metre of pure flight.

Good luck on your project! You're definitely going to finish it!

KNEX! ..I missed those god damned things.

Yeah. I was ready to an hero because I thought poison was smarter than me for a second.

Ooh, awesome!
Some of my classmates a few years back made a small, functional trebuchet out of pencils

Side view drawings are completed, moving on to front and overhead views.

As a side note, the designs had me stumped because it's been forever since I've had Geometry. I mean, I know everything I had to, but I forgot little things that messed me up and caused many days of headaches. Not realizing that I wasn't accounting for the entire equilateral triangle legs' height was messing me up.

Quote from ClansAreForGays

Yeah. I was ready to an hero because I thought poison was smarter than me for a second.

BTW, what exactly is "an hero" supposed to mean?

Google it for more info, specifically the ED page. It's terrible what they did to that poor family.