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

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.

Comments

[harrydo]

I mean where do you put the counter weight?

[harrydo]

how can you add a weight to it?

[thatblackguy]

YOU GUYS ARE ALL SUPER SEXY BTW. ;) ;)

[thatotherblackguy]

hey thatblackguy

[thatotherblackguy]

i agree with thatblackguy ;) ;)

[young skipper]

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.

[ineverfinishanyth]

Thank you!

[MR.builderguy]

funny. I have the same scroll saw.

[timmy01]

neeto!!!!!!!

[richhersey]

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

[THERCNERD]

how tall is this trebuchet?

[ineverfinishanyth]

With the throwing arm extended vertically, its between 6 and 7 feet.

[knexsuperbuilderfreak]

can you make a template?

[ineverfinishanyth]

well i could have a page with all the demensions but i don't think i could a make a print-out-"able" template

[hintss]

kinkos and ask about wide format printing. its expensive, though

[Shelexie]

This is a great tutorial!  Thanks for the ideas!

[spark master]

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 !!!

[graysonipper]

I made one out of wood with similer dimensions but double size I just fired it into a few houses over

[Riojelon]

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

[Dudemaster]

Hi,
can you post measurements in metric as well?

Thanks,
Γι¬ννης

[112251919112]

dude, this is awsome

[Analton]

+1!

[pyra_builder_1337]

neat i may try to make one out of actual wood but this is very innovative

[TCInc]

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]

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)

[TCInc]

Is A2 part of A1? It looks like they fit...

[ineverfinishanyth]

yes, they fit together to form the counterweight "basket" of the trebuchet

[the poodleo]

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.

[GianniMora]

how far does this shoot.

[ineverfinishanyth]

This throws a softball 50-60 feet. Heavier objects will not go as far

[GianniMora]

ok cool

[georges bou]

wonderfull

[kurth92]

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]

the counterweight is basically a hollow container in which i can place bricks, rocks, or anything else to provide the weight.

[soccercheese33]

With your first "technically deficient video" what is the final noise in it? contact? Was your quad layer board from a food business? And if you were to take it to a surface not of asphalt or concrete have a cardboard slide/bed that the projectile would slide along to provide minimal resistance in return providing better performance!

[ineverfinishanyth]

the noise is the projectile hitting an old scrap of sheet metal that was on the hill randomly my quad layer cardboard was not from a food business thanks for the tip i'll try adding a cardboard "bed" to reduce friction

[totally_screwed]

I researched trebuchets some years ago and while I was composing a post that might be of use to those interested, I happened-upon the trebuchet page in Wikipedia, which had almost everything I had found!

Since the behaviour of a trebuchet can be unpredictable, a good simulator is recommended. Remeber, the shot may go backwards, forwards or even straight up!

google trebuchet simulator

[totally_screwed]

The last instance of trebuchet use comes from the New World, at the siege of Tenochtitlán (Mexico City) in 1521. As ammunition was running critically low, Cortés eagerly accepted a proposal to build a trebuchet. The machine took several days to build, and at the
rst launch the stone went straight up, only to return and smash it.

[ineverfinishanyth]

while adjusting my release time i had a shot go straight up...and come back and smash my hand

[snworks]

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!