|Project by Jim55||posted 11-07-2012 09:24 AM||3039 views||9 times favorited||8 comments|
A home-school project encompassing understanding many things- history, engineering, physics, ballistics and yes, wood working. Also some fun. :)
Our projectiles are typically marbles. They seem to combine the best combination of size and weight. We have broken the 100’ distance a couple times but about 85’ is the norm. Eight pounds is the most weight used.
The string wrappings are functional to help hold things together where the throwing beam is pierced for the trunnion. There were no plans, the design was our own based upon several working examples and largely influenced by “War Wolf” a BBC sponsored attempt to recreate a full sized trebuchet from history.
I believe the design needs improved. The counter weight seems to just drop down with a jerk rather than swinging an arc. I believe the frame needs to be taller and more length of beam from trunnion to counter weight pivot.
There is one neat thing, the engine creaks with rubbing wood making it sound more like a massive machine. I believe the sound is the by-product of some binding in the build. It is held together by toothpick ‘pegs’ and the bindings. Wood is a collection mostly of pine scraps but some pieces of hickory. The counterweight basket is made of that.
Anyway, it was fun building it with the boys and we enjoy ‘shooting’ it. By the way, “Mammoth” is just what we named it and some one day, a considerably larger, say, about a 6’ high frame, is in the works. Should be fun!