Author Topic: Catapult Build (Read 3253 times)

carronader · « **on:** March 26, 2009, 11:52:29 PM »

For anyone thinking of getting into this side of things.Maybe of help.

Victor3 · « **Reply #1 on:** March 27, 2009, 01:01:17 AM »

Nice little peashooter. How many peas can it shoot at once?

carronader · « **Reply #2 on:** March 27, 2009, 05:57:02 AM »

BornSouthern, have you thought about using your 2 inch tubing to build the frame and then experiment with the arm,would be a very good test bed for the most important bits - the pivot and the arm.Drawing I put up is ok for basic build in wood or tube and is a good stable platform,scale is good but can be changed to suit.A single tube arm could give you loads of problems at the pivot as some kind of cruciform would need to be attached(welded) Timber with an axle to either end of frame is simple.Got another drawing somewhere of possible solution I'll look for it.
Victor,
Never thought of launching peas,as hauling out a large launcher of any kind in UK would bring out the police helicopter it's better to keep your head below the parapet or apply for the three thousand permits you would probably need.

carronader · « **Reply #3 on:** March 27, 2009, 07:06:43 AM »

quality is bad but should give you ideas on how your tube could be used.

carronader · « **Reply #4 on:** March 30, 2009, 03:08:36 AM »

neat little trebuchet

carronader · « **Reply #5 on:** March 30, 2009, 03:10:35 AM »

and more

tapwater · « **Reply #6 on:** March 30, 2009, 05:09:14 PM »

Gotta tell you, that's a spiffy looking machine. Since my farmer buddies and I have taken our air cannon about as far as we can, a trebuchet or catapult may be next. We're not very good wood butchers, so it will probably be in steel. We don't try to be historically correct, but rather try for ease of manufacture and maximum performance.

carronader · « **Reply #7 on:** March 30, 2009, 11:34:51 PM »

Because I build small stuff,I can take time to polish/shape little bits of metal,use hard woods and generaly mess about to try to make things look good.If I had the freedom you amaricans still have I would be goin after big lumps........goin skyward........at a huge rate of knots,built from whatever I had available or could beg or 'borrow'.
For me,I prefer the ONAGER (catapult) more accurate and you can launch incendiaries safer but for pure awesome distance it has to be the Trebuchet.If you've just thrown a bowling ball 400 yards from something you and your buddies made in your yard for a minimum of dollars.............are you really worried what the 'experts' say.
Anyway once you get hooked you will want to see what you can do with traditional stuff.(trust me I'm a Scotsman

) Remember we gave the world Golf and look how rewarding that's been to marriages,bank balances and sanity

goodconcretecolor · « **Reply #8 on:** April 09, 2009, 03:40:15 PM »

My older son had to build a trebuchet for his high school physics class. They had to throw a 1 kilogram piece of produce as far and as predictably as they could. An additional rule was the team had to carry their trebuchet into the second floor physics class room and back out to the firing line out side. They estimated 58 meters and had throws of 57, 59 and 61 meters. The machine was about 6 feet tall and used a weight of 200 lbs. It was so cool to watch. My son is a sophomore engineering major now with one of his teammates there with him

carronader · « **Reply #9 on:** April 09, 2009, 11:38:40 PM »

yet another reason to keep alive forums like this,to get kids interested in science and engineering there is no bigger hook than cannons-catapults-rockets.They cannot all be computer games creators.
The reverse is also true,highly educated people can be reduced to 10 year old kids just by seeing any of these being fired.

gstewart44 · « **Reply #10 on:** April 10, 2009, 04:13:13 AM »

On a larger scale - Several years ago one of my hunting buddies brought his college age son up one summer whilest we were having a work weekend at the camp. His son thought it would be cool to build a treb. He put it together that weekend and set it up by our shotgun field. He then would launch plastic water bottles, unopened soda cans, and old tennis balls for some fun wing shooting. When you would say "pull" you would have to wait for that sling to come around and then acquire the target.

Too bad it burnt up in the wildfires of 2007.

carronader · « **Reply #11 on:** April 10, 2009, 04:30:52 AM »

build another one

tapwater · « **Reply #12 on:** April 10, 2009, 06:28:43 PM »

Just wanted to say thanks to you guys for posting and keeping this forum alive. I've been working some really long hours and just don't have the time or energy to participate right now. One of my punkin chunker buddies has a CD full of great pics of one of our shoots. When I get time, I'll upload some of them and post 'em. There are some great shots (pics) taken at 3 frames per second. You'll love them.
See ya'll later. Dale (tap)

ol smokey · « **Reply #13 on:** April 14, 2009, 09:26:32 AM »

im hoping to build a trebuchet over the next few weekends. i want to build one that is big enough to throw a bowling ball. anyone know where i should start?

carronader · « **Reply #14 on:** April 15, 2009, 12:56:59 AM »

Smokey,to give you an idea of scale I've posted a link to a working machine throwing one,you're idea of timescale is maybe a bit optimistic,a bowling ball travelling at speed has got to be treated with respect.Your counterweight alone ,just making the drop needs controlling.Have a look at the vid.
http://www.youtube.com/watch?v=cF6ADeZmORY
Before you start thinking the UK has been legislated into a bunch of old women,check out this link.We still have a bit of adventure left.........
http://www.youtube.com/watch?v=wVADKznOhY&NR=1
For basic design my previously posted drawing holds good,with obvious consideration given to bearings,structural strength,and major attention to the sling and pouch.
Remember the guy in the second link probably owns the land in a 5 mile radius ,so he doesn't need to worry too much about permits,health and safety inspectors and telephone calls to the police from ' concerned citizens'

carronader · « **Reply #15 on:** April 15, 2009, 01:15:21 AM »

Second link should read............
http://www.youtube.com/watch?v=wVADKznOhY&feature=related

ol smokey · « **Reply #16 on:** April 16, 2009, 07:27:13 AM »

that's pretty much what i was picturing in my head. i have about a 1 mile wide shooting lane about a mile and a half long. i cant see it going further than that. any info out there on where to start? or should i just learn with making something a bit smaller say in the 5' range? i guess i just dont know where to start.

carronader · « **Reply #17 on:** April 16, 2009, 07:57:00 AM »

If you take the drawing at top of this page........multiply the dimensions by 6 that gives you a throwing arm of around 10 feet........should be big enough.........start off throwing a pumpkin or such for safety.......watch out for any frame weakness.....add support (nail on extra bits-bolts would be better) and off you go.
That frame should be capable of taking a longer arm ........maybe 12 feet if needed. You got to start with a frame and arm..........trigger-sling-conterweight(wooden box full of concrete )can all come later,I'm sure you'll get more people coming in with ideas for you once you hit a specific problem.

ol smokey · « **Reply #18 on:** April 16, 2009, 08:24:54 AM »

thanks! ill take pictures as i go along to post and share. my pickup is in the shop so i wont even be able to start grabbing supplies until next weekend. i'm excited my 13 year old son is going to help me build it. should make for some fun if it stops snowing.

carronader · « **Reply #19 on:** April 17, 2009, 12:56:03 AM »

Maybe these posts will help,you're a lucky man to have your boy still wanting to do stuff with you ,it's painfull when you lose them to computer games.....their friends.......t.v. :-[So quit jawing and start making.

ol smokey · « **Reply #20 on:** April 17, 2009, 06:52:32 AM »

i know how easy that can happen. when my daughter started on that road. i bought a 40 acre farm. we only let the kids have one hour a day or TV, computer, or games. they do have unlimited access to shooting, dirt bikes, horseback riding, and such. it's a very nice change of lifestyle. we have been out here for 5 years. i wouldn't change anything.

carronader · « **Reply #21 on:** April 17, 2009, 07:18:16 AM »

I envy you the room to breath,I went from West Scotland ,now in stinky London,will post a photo of my old home golf course.Wish I had the freedom to build the big machines,Boy o Boy do I have some mad ideas,

most of them would be censored.Canons and catapults,once your hooked..........you're a goner.

ol smokey · « **Reply #22 on:** April 17, 2009, 08:17:44 AM »

wow that's beautiful. i live out on the plains in Colorado. not very green this way. this is a picture of my three youngest flying a kite.

carronader · « **Reply #23 on:** April 18, 2009, 04:45:28 AM »

You got room there to start your own horse clan,set to making more kids...........sweep across Colorado......today-the farm.....tomorrow the State.How do you think Ghengis Khan got started.
I would be looking for ground source of water,build a lake,then the shore battery,next comes the English 74 gun ships of the line,then of course the model city.........under siege of course from 3 Roman legions.........O well we can all dream,would only take a couple of million dollars,small change for guys like us.

BoomLover · « **Reply #24 on:** January 19, 2010, 09:36:50 PM »

Carronader...good to see you here, too! I have been thinking of building a small Treb. with PVC, maybe in the 4-5 foot range...had a drawing and now can't find the silly thing...any hints, tips, weak points, ect? Love that pic of your old homestead, beautiful country! My Great great Grandfather was Levi Scott, founder of Scottsburg here in Oregon...came from Illinois, but his parents came from Scotland...Scott Clan, Edinburgh area...BoomLover

NVWalt · « **Reply #25 on:** February 21, 2010, 05:28:38 AM »

Carronader,
Thanks for your input. I have been wanting to build a trev for awhile now and knowing some basics of it and your plans make things a lot easier. I enjoy scale building also and they make great conversation pieces also. You know not everyone owns one of those fine implaments of ancient warfare.
I have a friend that wants to build a large one but finances are a problem with a large one. Have thousands of acres here where I live to go out and shoot whatever we want. I couldn't imagine what it is like to not be able to play anytime anywhere and then be hassled by the powers that be. Thanks again....Walt

carronader · « **Reply #26 on:** February 22, 2010, 02:34:47 AM »

Walt, will get back to you within a couple of days with drawings......is no problem...just busy.....make sure I have your email address.