Crossbow
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Days needed: 2
Raw materials needed:
Objects: crossbow prod (1), bowstring (1), crossbow stirrup (1), crossbow stock (1), crossbow trigger (1), bow iron (1),revolving nut (1)
Tools needed: stone, bronze or regular hammer, screwdriver
A crossbow consists of a prod (similar in appearance to a bow) mounted on a stock similar to a rifle stock, which has a mechanism to wind and shoot its bolts. These bolts are typically called quarrels, and do not depend upon lift as arrows do. The stock and trigger of hand-held firearms may have been copied from crossbows.
Crossbow bolts must be made to have consistent weights as the mechanical process of engaging a bolt forces a more uniform process than that of using a bow and arrow. This consistent performance was part of what made the crossbow historically a significant force in warfare.
A crossbow contains a string which is held in place by a nut when the bolt is loaded and the cross bow is engaged (referred to as at full cock). Typically, the nut is at the end of the shelf (also called the bolt rest).
The prod ("bow") and stock of a crossbow were made of good hardwood, such as oak or hard maple. The central European bows were rather exotic as they were constructed of inlays as well as specialized woods. The prod is attached to the stock with hemp rope, linen, whipcord, or other strong cording. This cording is called the bridle of the crossbow. Much as a horse's bridle, it tends to loosen over time, and must be carefully respliced when appropriate.
The crossbow shelf is a flat section above the stock with a straight groove for the bolt to rest upon and travel along as it is shot.
The strings for a crossbow are typically made of strong fibers that would not tend to fray. According to W. F. Patternson, whipcord was very common; however linen, hemp, and sinew were used as well. Even cotton was tried with some success.
The crossbow also includes a trigger, which was later incorporated into rifles, muskets and other firearms. Triggers are known to have been used on crossbows from the early 1400s. Leonardo da Vinci designed many complicated triggers for crossbows, ultimately producing a "hair trigger" that could be shot with very little finger strength.
Crossbow bolts are lighter than arrows, but must be sealed with a varnish to ensure their consistent weight. They also typically only have two fletches per bolt instead of three commonly seen on arrows. This prevents them from snagging on the crossbow nut as they are shot.
