Picture of How to Make a Medieval Trebuchet Out of Cardboard
Of all the Medieval siege engines, the Trebuchet was by far the most accurate and complex. Trebuchets were capable of throwing 350 pound objects over castle walls. While in this Instructable we won't be making a Trebuchet with that much firing power, the design I will show you is capable of throwing a softball 50-60 feet with a 20 lb counterweight.

Video of me shooting the catapult:
(Sorry the video is sideways, I was having technical difficulties)

Step 1: Materials

Picture of Materials
The Materials that you will need for this project are as follows:

Cardboard! - You will need A LOT of cardboard for this project unless you are lucky like me and find some quadruple-layer cardboard lying around.

Glue - I used Gorilla Glue and suggest that you use the same.

(Optional) Clamps - If you are using Gorilla Glue, you will most likely need clamps to keep your pieces together while the glue cures.

Pipes/Rods - You are going to need pipes for the axles and joints. I used a 3/4 inch acrylic rod for the axles and 3/4 inch PVC pipe for the axle to slide through.

Washers - You will use these to reinforce the joints that will be holding the counterweight and the the "arm" of the catapult. I used washers with a 7/8 inch hole.

Drill+Drill Bits - Depending on the size of your axle, you will need corresponding Drill Bits to make your holes. I used 13/16 inch and 5/8 inch.

Newspaper - Newspaper works really well when you are making your patterns for the cardboard

Rope/Cord - This will be for the "sling" that throws the projectile

Denim/Canvas Fabric - Also for the "sling"

3/16 Inch Steel Rod - This is also for the sling and only needs to be about 6 inches long

You will also need something to cut your cardboard into shape. I used a scroll saw but a knife or other saw might work.

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great, well done

Westornd made it!1 year ago

Thanks for this instructable. I could make a miniature version. ^^

Ha, I was randomly looking for things to make on this site and I saw this on the cardboard guide and was like "Is that a cardboard trebuchet?". This is truly amazing.
That was MY REACTION EXACTLY. With the then-instant addition of "*CLICK*".

Fantastic. My wife is going to just LOVE it when I dive into making THIS. Great!
Thank you!
fustigator3 years ago
Very impressive - just though I'd comment because youtube now have an 'edit' feature that lets you rotate your video. Keep up the good work, I watched the huge treblochet at warwick castle hurling a flaming cannonball this weekend which is why my internet wanderings have brought me here!
harrydo3 years ago
I mean where do you put the counter weight?
harrydo3 years ago
how can you add a weight to it?
funny. I have the same scroll saw.
austins pics003.JPG
timmy014 years ago
richhersey4 years ago
What is the biggest challenge you've had with building a Trebuchet?

I'm building a book with tips on building a Trebuchet and would love any tips or advice you have from building a Trebuchet.

Here is the survey form. I did a survey so I can have all the tips gathered from different forums in one place.

Trebuchet Survey
THERCNERD4 years ago
how tall is this trebuchet?
ineverfinishanyth (author)  THERCNERD4 years ago
With the throwing arm extended vertically, its between 6 and 7 feet.
can you make a template?
well i could have a page with all the demensions but i don't think i could a make a print-out-"able" template
kinkos and ask about wide format printing. its expensive, though
Shelexie5 years ago
This is a great tutorial!  Thanks for the ideas!
awesome, awesome awesome
suggestions put some wood in crucial areas for stronger,(longer lasting)  device , you could use old wall paneling for uter most layers or all the layers(you can cut with razor utility knife and do everything EXACTLY as you did here. it would be much stronger.

I think your push pull on the release arm was sheer elegance (simple), and if you do wood make it threaded rod into a nut set in the wood/cardoard arm then you can simply make it longer shorter by turning it.

thanks this was truely magnificent. My kid may want to build one, me too !!!
I made one out of wood with similer dimensions but double size I just fired it into a few houses over
thats a great idea! But don't use heavy wood on part c. use the heaviest avalable wood on the part a. for more power, lenghten part c
Dudemaster5 years ago
can you post measurements in metric as well?

dude, this is awsome
neat i may try to make one out of actual wood but this is very innovative
TCInc5 years ago
Hey, can you glue two cardboard together to make a bigger one for part B? If you can't, where did you get that big of a cardboard?
ineverfinishanyth (author)  TCInc5 years ago
The cardboard I used was from a 4 foot tall box, so that is how I got pieces that big......as for making part B with smaller pieces, you could cut out several smaller pieces and stagger them. This would create a semi-strong piece for part B that might do the trick. You would stagger the pieces much like a brick wall is staggered (see picture below)
TCInc5 years ago
Is A2 part of A1? It looks like they fit...
ineverfinishanyth (author)  TCInc5 years ago
yes, they fit together to form the counterweight "basket" of the trebuchet
snworks6 years ago
Very cool! Try putting it on wheels so it can roll easily back and forth in the same direction as the throw. It seems like the wrong idea, but it allows the counterweight to drop down in a straight line, instead of an arc, so more energy is transferred to the missle being thrown. I have seen it add distance. Worth an experiment!
ineverfinishanyth (author)  snworks6 years ago
Thanks for the idea i'll try adding some cardboard wheels now!
Old lawnmower wheels would be great if you had some..
I was going to say this too! Saw a great documentary on the BBC or Channel4 in England a few years ago. When they added wheels it stopped their trebuchet from rocking back and forth and made it much more accurate and powerful. The difference was remarkable. Just what every would-be conqueror needs!
Yes, I was that documentary as well, but I believe the wheels allowed it to rock back and forth, which changed the dynamics and improved the throw. It will be interesting to see if ineverfinishanyth belies his name and does a test with wheels.
the poodleo6 years ago
i thought this was just a mini one, so im gonna try and make a little desk one like about 10 - 15 cm.. it would be cool if it shot as far as this one in the video.
GianniMora6 years ago
how far does this shoot.
ineverfinishanyth (author)  GianniMora6 years ago
This throws a softball 50-60 feet. Heavier objects will not go as far
ok cool
georges bou6 years ago
kurth926 years ago
im impressed not by the cardboard people who make catapults normally go alright but people who try trebuchet normally fail it all in the sling so tell me the the counter weight completely cardboard ?
ineverfinishanyth (author)  kurth926 years ago
the counterweight is basically a hollow container in which i can place bricks, rocks, or anything else to provide the weight.
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