Trebuchet

[Ianab]

Now this is FUN

Yongest boy has a science project - built something to throw a hard boiled egg as far as you can  ;D

Now explosives and school projects is probably out - so it's got to be a catapult.
We knocked it up this afternoon. The teacher wisely set size limits on any machine  ;)





Using a golf ball as ammo, the 2nd shot ended up in the neighbours garden 8)
After that we re-orientated the firing range, and are getting about 25ft with a golf ball.
Need to do a bit of experimenting with the sling and release timing to tune for max range, but I'm impressed. The counterweight is a small electrical transformer, the heaviest compact object I had on hand  ;)

There is already talk of a scaled up MKII  :P

Ian

[Paschale]

Very, very cool!   8)  I'm thinking your son'll get top honors for that baby!

[Tom]

WOW!  What a project.  You must make a scrap book of this for his keeping. 

[Furby]

I was called in to help out my Uncle's Daughter several years ago with the same type project.
She ended up with a 2x4 mounted to a piece of 2x8 or plywood with a hinge. Attached a spring between the two and pull the 2x4 all the way back the other way. Had a little cup on the end of the 2x4, and could launch a tennis ball a good 30-50'.
Her teacher requested the project as an example for future classes as it was the best he had seen.

I have to say that your boy has one fine looking project on his hands, and I'd love to play with it!  ;D

[Corley5]

 8) 8) 8)

[Percy]

Heya Ianab.
Doing stuff like that with your kids is great, and alot of fun too. He'll remember the time  together longer than you ;D

I see you are using golf balls as a substitute, wassamatter, run outta chicken friuts?? :D :D :D :D :D

[Rockn H]

Thats a nice looking Trebuchet.  I like seeing how much energy you can store before ya gotta let it go. ;D  It's a good thing the teacher set size limits, you know how excited some dads can get, liable not find them eggs.  I guess something along the lines of a pumpkin cannon is out of line? ;D

[Doc]

Very Cool!! My kids would be firing those eggs at me though 8) 8) 8) 8) 8) 8)

I am sure his teacher will be impressed.  ;D ;D ;D

Doc

[Ernie]

Hey Ian

Keep the eggs for a couple of months and do some testing in parliament, at least that should keep them awake :D :D

Ernie

[Dan_Shade]

I don't know how I missed this one the first time around!

I made a big one of these out of an old picneck table, i'd use it to toss my mom's bad vegitables from the garden, lots of fun

[Tom]

I'm wondering how the teacher took it, and how the contest went.   Did he win?

Dan, you wouldn't happen to have an old picture of the picnic table catapult, would you. :D

[Dan_Shade]

i'll have to see if I can find it, that was prior to digital cameras.

hah, my mom "loved" that thing, old rotted up recycled wood it finally met it's second demise in a wind storm, the counterweight caused the whole thing to pretty much demolish itself when it blew over.

the little ones are a lot more fun to play with, I made one about like in the photo above.  easier and safer to set them up and all of that stuff.

[rebocardo]

Ever see Max X where the U.K. farmer (?)  throws the compact car a few 100 feet and to make a hole in the floor board he blasts it witha shotgun and then they throw the gas tank too? It is a scream.

[Ianab]

I'm wondering how the teacher took it, and how the contest went.   Did he win?

Yup.. the catapult cleaned up.
With a new sling and a bit of fiddling with the release hook he was getting 36ft. Not bad for a little toy like that I thought.
That size is safe enough, but the arm flicks around at a fair speed, I wouldn't like to get my knuckels in the way 
The wood is bluegum Eucalyptus, it's slightly denser and harder than oak, so it handles the heavy counter weight. (the plan called for a 2 lb weight... we ended up a bit over 5 lb)  :D

Cheers

Ian

[Teri]

I bet that was fun!  ;D