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Measure Twice, Cut Once...

We need to start out by cutting all the pieces of wood that we will need.

I gave you a brief look at the sizes of wood you will need to have after they are cut. I will go into more detail now... Keep in mind, I am going to give you exact directions on how to build the trebuchet that I built. Doing it your own way is always promoted here at GhettoRigIt, just make sure you stick with these basic ratios in your head:

• The ratio of the long section of the throwing arm, to the short section of the throwing arm should be about 5:1 or (4:1 if you are planning on throwing massive objects to cause great and glorious destruction).
• The ratio of the counterweight to the projectile should be about 100:1. If you use a 10:1 ratio, you may be sadly disappointed!
• A good point to cock your trebuchet back to is about 30 degree under the horizontal plane of the axle rod.
• The vertical arm that holds the axle rod and should be as long as the short arm + the height of the counter-weight container + the distance between the container and the short arm (if any...) + about 2" of lenience for the counter to clear the trough at the bottom of the machine.

Okay, any more detail than that would be too much to provide on this site. Those are good rough ratios to help guide you if you choose to stray from the rigidity of this article. From now on, I will assume you are making exactly what I did.

So, here is a list of all the cuts you need to make with your wood.

Actually the only ones that really need to be shown are the two types that have angles on the ends. Keep in mind that these are 45 degree angles:

In the whole scheme of things, this is the smaller of the two diagonal supports for the vertical beam that supports the axle rod that the main launch arm rotates on. It is important that the vertical beams stay as stiff and sturdy as possible. When you are dealing with the forces a trebuchet creates, you need to keep in mind the stresses that the centripetal forces create in the x, y, and z planes. If you don't attach the vertical planes PERFECTLY vertical (essentially impossible), you are going to have the frame moving in unpredictable, or, rather, undesired ways. For these reason, there needs to be myriad supports holding up the vertical support beam. This is the small one. There is another that is 12" longer, but is the exact same design. I will show you how these will attach later. For now, simply stick with cutting the pieces you need. This is using the 1.5" x 5/8" wood.

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