Trebuchet

Build a working scale model of a medieval siege engine by Russell Miners

In the Dark Ages, before the invention of gunpowder, the trebuchet was the most powerful artillery weapon in the world. A successor to the catapult, the trebuchet ("tre-boo-shay") acted as a giant sling to hurl 2,000-pound boulders, red-hot irons, and (on some occasions) unsuccessful negotiators over fortress walls 500 feet away.

My "treb" is a downsized version of a typical Dark Ages model. It can hurl small stones up to 70 feet. I'll also attest that it can heave a grape across a formal banquet hall.

Regardless of size, all trebuchets work on the same principle, which any kid who has played on a seesaw can understand. When you place a rock (projectile) on the low end of a seesaw and force the high end down abruptly (apply a counterweight), the low end accelerates upward and the stone gets tossed in the air. The main difference with a trebuchet is that the projectile end of the treb's beam, which is longer than the counterweight end. has a sling attached that increases leverage and typically doubles the throwing range. Also, the axle is high enough to let the counterweight swing all the way down without hitting the ground. (See "How a Trebuchet Works," below.)

How to Build It

I built my treb from oak, but you can use almost any wood spccies. Many medieval trebuchets were built with interlocking joineryr. A small model like this one can do fine with glued butt joints that are reinforced with dowels or with a few screws at strategic locations.

I have provided dimensions for this particular model. (See Fig. 1.) If you want to build a bigger trebuchet, beware: you can not simply scale it up proportionately. Big trebs require stronger joinery, for one thing, and the bucket's volume should be proportionately smaller in a larger treb.

You can build your own treb in four stages: counterweight bucket, beam, base and firing mechanisms.

Start with the bucket, Early trcbuchcts had a fixed counterweight at the short end of the beam, until it was discovered that a hinged counterweight provides greater downward thrust and stability. So I made a bucket with suspension arms and an axle, so it can swing from the short end of the beam.

To make the suspension arms, I laminated two '/2-in.-thick pieces together, bur you can use 1-in.-thick stock if you wish. Glue and screw the suspension arms to the bucket sides before assembling the bucket. During assembly, keep the suspension arm's axle holes aligned with a '/2-in. dowel, but don't glue the dowel in place.

I filled 13 plastic 35-mm film canisters with lead shot and loaded them in the bucket. This brought the bucket s weight to 7'/2 lb. You can also use steel bar stock, washers or any other compact counterweight.

Text continued on page 66.

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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