| Project by Jim55 | posted 195 days ago | 1343 views | 8 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!
| Pin It |
8 comments so far
Monte Pittman
home | projects | blog
7060 posts in 506 days
#1 posted 195 days ago
Pretty cool. Looks like fun.
-- Mother Nature created it, I just assemble it. - It's not ability that we often lack, but the patience to use our ability
Tom Godfrey
home | projects | blog
388 posts in 344 days
#2 posted 195 days ago
Nice. I want to make one of these one of these days. Just to business playing catch up now but maybe later on. You need a great job
-- Tom Godfrey Landrum South Carolina (tom@thcww.com) 864-384-4938
HalDougherty
home | projects | blog
1820 posts in 1405 days
#3 posted 195 days ago
Great looking siege machine… Lego forts are quaking in fear! Have you seen the 'Punkin' Chunkin' website where they show off modern trebuchet’s. The projectile is an 8 lb punpkin. Google it and build a big machine to compete next year.
http://www.punkinchunkin.com/results/2012
-- Hal, Tennessee http://www.first285.com
Jim Jakosh
home | projects | blog
7258 posts in 1273 days
#4 posted 194 days ago
Nice looking trebuchet.
The jerky drop may be due to binding in some of the pivots. Maybe opening up the holes for more clearance may make it smoother!!................Jim
Hal, I looked at the records this year and 3800 and something was the best. Didn’t they have one go over 4000 one year?
-- Jim Jakosh.....Practical Wood Products...........Learn something new every day!!
ChrisK
home | projects | blog
530 posts in 1249 days
#5 posted 194 days ago
Great build. I am almost done with a 6’ foot design for tennis balls and water balloons. My son’s scout pack will use it on our camps to toss water balloons. It should be able to hold 100# of counter weight, though 40 to 50 should be enough for balloons.
Mostly 2X construction, bolted together to help with transport.
Have fun. Try making the sling a little longer.
-- Chris K
Jim55
home | projects | blog
125 posts in 234 days
#6 posted 194 days ago
Punkin Chunkin is a blast! Watching that is loads of fun!
You know, I hadn’t thought of making the sling longer over all. We’ll give that a try. We did add the chain links so we could adjust the trajectory. One link can lower it from a nice low angle shot to a high angle lob.
Ben Simms
home | projects | blog
180 posts in 459 days
#7 posted 194 days ago
cool
-- I played with Legos as a kid and I never had the part I thought I needed, so I learned to improvise. Now I'm an engineer with a woodworking hobby.
exterminate
home | projects | blog
59 posts in 195 days
#8 posted 194 days ago
This looks like a fun project. Great job! I’m filing this one away so that one day, I can build one with my boys…..
-- Albert Einstein - "I'd rather be an optimist and a fool than a pessimist and right."
Have your say...