How to build a trebuchet catapult?

Question

I need to build a catapult for class.

I do not want to do it but am trying

the weight of what I have to fling is about the weight of a golf ball,

the catapult has to be under 50x50 cm

and it has to fling it a distance of 8meters

anyone have any help?

I've been trying to use the internet but.. beh

so far the catapult i've made only flings things about a foot.

Answer 1

Trebuchets are complex pieces of equipment, and have many variables.

Mass of a golfball = 0.04569 Kg

50 cm = 19"

8m = ~27 feet

I plugged some values a treb simulator on my mac

height of axle= 18", .457 m
length of arm from axle to CW = 4", 0.1016 m
length of arm from axle to firing pin = 20", 0.508m
length of sling lines = 12", 0.3048m
length of CW hanger = 2", 0.0508m

mass of Cw 3 Kg
mass of projectile =- 0.04569 Kg
mass arm = .3kg

The program calculated the range to be 8.1m increasing the CW mass would increase the range. The range effiency was 32%, good for an HCW.

I havebuilt 3 trebs, the largest of which is 15 feet.

If your treb has similar dimensions, then the problem is the cw mass or the firing pin angle. If the treb is throwing the projectile into the ground with alot of force, bend the pin back a way (towards horizontal). If the treb just throws the ball late, add CW mass.

CW = counterweight

I hope that helps!

Answer 2

1

Answer 3

The internet should be one of your best sources. If you need some 'hands on' type advice, contact the physics department of any college close to you.
My trebuchet is about 18 inches high, has a five pound weight, and will fling stuff all the way down the hallway (about 20 to 30 feet).
There are a lot of variables involved, but the first one that comes to my mind is whether you made it all in one stable platform or if you put it on wheels or used a swinging or a fixed weight. Those can effect the distance tremendously.
If the site you are working from doesn't address those issues, find another site.

Answer 4

The trebuchet folks are well organized and got the obvious web site, see below. Did they require you to make a trebuchet? That's quite a long way for a small trebuchet. You are going to need a comparitively large weight and a pivot near the weight to get the speed you'll need.

Answer 5

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Answer 6

A few years back Scientific American magazine published an article about this mediaeval weapon, which was used to launch infected animal carcasses into besieged castles; an early form of biological warfare. It consisted of a seesaw with the dead animal at one end and a hoist which had a heavy weight on the end of a rope wound round a drum. You wound up the drum, lifted the weight a few metres then dropped it on the other end of the seesaw. The authors built a copy of a mediaeval trebuchet and they were able to send a small car flying about 100 metres through the air.

Answer 7

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Answer 8

You need popsicle sticks,(make a platform out of them), hot glue guns, and strong string. I did this before for my industrial tech class and its quite simple, you just have to make sure its even on all sides. Good luck =)

Answer 9

http://www.ripcord.ws/plans/plans.html and scale it down