Introduction: The Office Siege Weapon Series: the Pencil Trebuchet

Picture of The Office Siege Weapon Series: the Pencil Trebuchet

this is the ultimant office war-waging weapon. now, you can have this beutiful piece of history on your office desk for only 5$ or less. this project may look complicated, but really it shouldnt take you long to be firing paperclips and staples across the cubicles. (Its too bad i didnt know about instructables during the office supplies challenge!)
i am not responsible for anything you hapen to do with this. it would be a good idea not to aim staples at people, by the way.

P.S. (this is my first instructable, please help me out with constructive critism. Thanks!)

If you enjoyed this ible, you'll really like my pencil ballista:

Step 1: Materials

Picture of Materials

if you are like me, i usually look at the materials and say 'too many, not gonna do it.' but trust me, most of this stuff you can find sitting at your desk.

What you need for materials is:

-A box of 12 or more pencils(1$)

-Thick paperclips(1$)

-tape (I used electrical tape) (50 cents)

-rubber bands (1$)

-film canister for counterwheight (I used pill bottle ) ( fill with whatever, fishwheight,rocks, batteries, ect.)

as for tools, all you really need is:

-Drill or dremel tool with really small drillbit (about the width of paperclip)

-exacto-knife or pocketknife

-glue gun and glue


Step 2: Make the Frame Part One

Picture of Make the Frame Part One

to make the frame for your trebuchet, the first thing you do is cut half of the tips off of the wood end of four pencils (look at pics). glue two together at about a 60 degree angle.

now, cut an indentation about 3 inches above the eraser end of the frame on both sides. then, trim another pencil to fit in these, so that you end up with an A-frame shape. (you should have two A-frames now.) Next, drill a hole in the top of the A frame where the two pencils are joined.

Step 3: Make the Frame Part 2

Picture of Make the Frame Part 2

to conect your two A frames, cut one pencil in half. then, slot the ends like in step one and glue together the A frames at the base. Do this on both sides as shown.

Step 4: Make the Throwing Arm

Picture of Make the Throwing Arm

first, you need to take two scrap pecies of pencil and glue them as shown. then, renforce the connection with electrical tape so the two pencils dont wiggle. (you may need to use three scrap pieces to connect them. i used three because i ran out of hot glue.)

then, you drill a hole at each end and one about three inches up from one side paralel to the other two.

after that, cut a piece off of a paperclip about two inches long. then, secure it to the longer end of the arm with rubber bands or glue.

Step 5: Make the Counterwieght

Picture of Make the Counterwieght

for the counterwhieght, first you must drill a hole through both sides of the container. fill the container with your wheight (water(not recamended), sand, fishwheights.)

then, bend a strong paperclip into the shape below. thread the paperclip shape through the hole closest to the hole in the middle of the arm so the arm is in the raised part of the shape.

you then thread the ends of the paperclip into the holes in the container.

Step 6: Make the Sling

Picture of Make the Sling

to make the sling, first cut two lengths of string two inches longer than a pencil. then make a tiny loop out of a paperclip. tie this to one end of a string. tie the other legth of string through the hole at the other end of the arm.

to make the actual sling, take two pieces of electrical tape about three inches long each and stick them together. cut a tiny hole in each end of the sling. then, tie one legth of string through each hole as shone.

Step 7: Finish It Up!

Picture of Finish It Up!

to finish this project, you unbend one of your paperclips and slide it through the holes you made in the A frames. as you do that, also slide the paperclip through the hole in the middle of your throwing arm. next you need to twist the ends of the paperclip around the A frame.the last thing you need is to cut a notecard in half. then, tape it to one end of the frame to form a ramp.

Hooray! you finished the Pencil Trebuchet!

fyi: (you can also make a realease system out of string and paperclips.please, if you have any ideas on a good reasease system, please post a pic!)


Heywasup (author)2009-06-15

does anyone else have a tendency of gluing their fingers together with krazy glue???

mo5 (author)Heywasup2009-08-19

yes,yes i do

draghi (author)mo52010-03-20

go to Google imgs and type "I Like" don't hit enter and there will be something like "I like to tape my thumbs to my hands to see what it would be like to be a dinosaur"... I glue fingers together once and a while to. also nice 'ible

1414Wes (author)draghi2010-04-05

i've glued my fingers together few times on accident

The nerdling (author)1414Wes2011-07-01

me and my bother put our hands in a jar of superglue once
the jar had a leaking tube of glue in it

Morgoroth (author)2008-06-24

What kind of distance can you get? Also, how heavy does the wieght need to be? And what kind of stuff do you usually throw?

zaro12345 (author)Morgoroth2008-06-24

well, curently, i can get about 15 feet throwing staples, pennies and such. but, if you used better string then fishing line, i'm sure you could get farther. Also, the counterwhieght varies by what you're throwing. A heavier counterwieght for a heavier projectile.

Morgoroth (author)zaro123452008-06-25

The sling is probably the part that is the most tricky for the one I am making. I could probably use fabric, but I think that would be cheating a little since I don't have any at the office and I want to make it as much as possible out of office supplies. However, I have made a sling out of one of those little empty mustard packets and some string and I think that it will work out once I get the other details fixed. How long should the sling be?

yumadome (author)Morgoroth2010-02-09

I was thinking about your 'no fabric in the office' problem...
I haven't tried building this yet so I don't have a feel for how much you need but it doesn't appear to be much...

You might look under your office chairs... many of them have the fabric pulled around the seat and/or back and stapled.  You might have enough extra sticking past the staples it could be trimmed off... then it would certainly count as coming from the office!

Either that or see if you can talk your cleaning staff out of a rag... it seems like that would be legitimate too.

That or raid the first aid kit for gauze?

yumadome (author)yumadome2010-02-09

Oops... I just noticed how old this thread is... ah well...

zaro12345 (author)yumadome2010-02-09

Eh, it's an old thread, but I do actually reply to comments (for the most part). Great idea, I might incorporate that into my Office Floating Arm Trebuchet instructable (when i get around to it, that is.)

zaro12345 (author)Morgoroth2008-06-25

this also depends on what you're throwing. For lighter projectiles, use a shorter legth. Heavier, longer. BTW, nice inginuity on the mustard packet. I didn't even think of that.

Morgoroth (author)zaro123452008-06-26

Thanks. I also made one out of a paper towel that works well. I doubt it would work for anything heavier than a penny, but it seems to work for that.

killerjackalope (author)2007-08-13

My Uber catapult and yes thats a heatsink as a counter weight, they can have a pencil jammed down the middle apparently... I took apart my old Xbox recently and saw the heatsink sitting there and it's pretty heavy. now tell me that's not fun

finally, someone else who loves to take apart things. nice job by the way. looks deadly.

brainiac (author)zaro123452007-11-23

who doesn't like takeing things apart?!?!?!

zaro12345 (author)brainiac2007-11-26

You'd be surprised at how many people cant even take apart a mechanical pencil and put it back together.

riverreaper (author)zaro123452010-01-03

baackkk together ? ...opps

wii552 (author)zaro123452009-12-23

 there's this person who was in my class in grade 6 whose mechanical pencil got jammed so she had to take the end off, and didn't know how to put it on-there was a rubber grippy thing that she didn't know could SLIDE

chi chi chippy (author)zaro123452009-08-15

lol i know that is so funny like at school and u take ur frends apart and watch them put it together lol haha

Fredward Sr. (author)zaro123452009-07-23

O so true

the gizmoman (author)zaro123452009-04-02

i love doing that

the gizmoman (author)brainiac2009-04-02

i looove taking things apart(drives my parents crazy cause i would bye electronic toys just to take them apart for their various components)

riverreaper (author)zaro123452010-01-03

yea people give me there junk now took me awhile to figura out it keeps me outa there hair if im preocupied taken there old {tape}answermachiens apart , i built a delecsick robot each motor works againts the other one an it does nothing but if it ever did move im sure its eyes would light up an blink

yeah check out my beer can USB hub its another child of my boredom but the major flaw in my design is that the trebuchet keeps breaking its own legs because it hates being the bastard child of an xbox and pencils as the pivot screw is also from the xbox lol

where do the legs break? also, you might need to make it wider so the heatsink doesnt run into the legs. also, you can renforce the legs by rubberbanding popcicle sticks like you did the throwing arm

that's actually string but the legs get knock apart by the force of the swing, it's actually very powerful

how far does it launch?

it depends on the projectile but the angle is hard to work I need longer stronger legs really

to adjust the angle, all you have to do is bend the wire on the end of the arm. test it out enough, and you can get a perfect angle.

the gizmoman (author)zaro123452009-04-02

have you ever seen the trebuchet from fryers kits (free paper model that shoots grapes 30 feet)

zaro12345 (author)the gizmoman2009-04-02

Yeah, it's pretty epic. Papercraft that actually does something!

try putting a renforcment bar to make the legs into an "A" shape. that should solve you problem.

master moose00 (author)2009-12-07

 hey zaro i cant grasp this concept one end of a string is tied to a ring the other end of that same string to the sling then the other string is tied to the sling and the arm? how does it shoot where does the ring come into play plz help thanks

steampunk-punk (author)2009-11-26

knife:) i alwase keep a knife in my office desk ppl dont steal my mints anymore

Ezlo (author)2009-04-06

How do I cut a pencil like that?

zaro12345 (author)Ezlo2009-04-06

You cut just to the lead with an exacto knife, then the wood should separate easy.

lucariothelegend (author)2009-03-28

bwahahaha! i built one and fired on in school. i hit one of my friends, and he fired his pen bow at me. but both of us got in trouble and got our weps confiscated...

Yeah, I allways build these paperclip catapults and fire them in class. My writing teacher has _sooooo_ many of my weapons right now...

heheheh.... i built an army of them, and use a wall of lego bricks as defense. both me and my friends fire pennies at each other point blank range

Cool. Yeah, i make a lot of little siege weapons.

me and my friend had a full war today, and i fired at the catapults first to disable them and i won

magical nerf yoyo (author)2009-03-28

lucariothelegend is BUSTED

abehambino (author)2009-02-21

instead of paper clips for the arm pivot, use a smooth pencil and lash it to the arm. then modifie the "A" frame so that the top forms a "V" cup to put the arm on. just thought that would make it capable of heavier loads.

piplup1118 (author)2009-01-02

o ok thanks

piplup1118 (author)2008-12-28

im sorry but i dont get this one either. i need help on the paperclip part bout the looping part can u explain to me how thats done,or what would be most helpful would be a pic of it if thats not to much trouble. i just liike a lot of detail and instructions sorry and thank u

zaro12345 (author)piplup11182008-12-30

There. I added an extra pic. Hope this helps.

piplup1118 (author)2008-12-23

i dont get step 4 can u explain it easier please

zaro12345 (author)piplup11182008-12-24

basicly, drill a hole in one side of the arm for the counterwieght sorry about the wierd wording.

piplup1118 (author)zaro123452008-12-26

its cool thanks for replying

About This Instructable




Bio: I'm a poor college student currently getting a degree in Mechanical Engineering, and working on a minor in Fine Arts. I enjoy a wide ... More »
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