Introduction: Pen Gun/ballista

Picture of Pen Gun/ballista

This is super simple and quick to make (also painful)

I’ve been looking around the site and saw many pen, rubber
band guns but I noticed they were a little complicated and
would take a minute or two to make , and the simple ones just
didn’t have the power. So I looked for my design and I haven’t
found it yet so I’m posting it for all you classroom commandos.

now for some reason every time i try and save my first step it
say error on page so bugger it its all going on one


Easy as pie (not pi, horribly complicated number)

1. A pen

2. A rubber band

3. sticky tape

That’s all but if you want to make it ALOT better you’ll get
those thick red rubber bands and a pen which has a thin
cartridge all the way along, no chunky metal bit at the point
like pic


now pull the pen appart into all of its components and keep
only the main tube and the ink cartridge

you then attach the rubber band to the tube like in the pic
with the sticky tape(if you want more power you can use
smaller rubber bands or have some extra rubber band sticking
out of the sticky tape to make it tighter)

and it built alternatively you could just tie the rubberband
to the tube for short term things.


if the rubber band is a bit loose and like in the pic hangs
then its fater and easier to load (but weaker)all you do is
drop the ink cartridgedown the tub so the metal tip is facing
out up when the gun is help like in the pic and grab onto the
other end with the rubber band and pull back, making sure at
least the tip is still in the tube so it goes straight, if
youve made yours tight (like i did) then youll have to make
sure that the rubber band is covering the bottom hole when
you "push" the ink down to be able to grab it to pull back,
let go to fire

i really dont suggest you aim these at people in less they
have thick jumpers on as at short range they break skin easily
and ive put one right through an aluminium coke can and still
hit some one on the other side.

enjoy and i dont accept any legal responsibility for damges to
persons or propery from the replication of this product.

when i can be bothered ill take a few photos of ones ive made
and of the destruction they can bring.
also this is only a basic model youll have to make your own
adjustments depending on what your materials are using


inoname (author)2014-11-03

I had also made a GUN which is like this pnly but much powerfull if u want to see it then visit

inoname (author)2014-11-03

I had also made a GUN which is like this pnly but much powerfull if u want to see it then visit

inoname (author)2014-11-03

I had also made a GUN which is like this pnly but much powerfull if u want to see it then visit

inoname (author)2014-11-03

I had also made a GUN which is like this pnly but much powerfull if u want to see it then visit

josiah.beltran.94 (author)2014-08-04

all you stuf suks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!1111

spartan1996 (author)2010-08-19

have a look on youtube for kipkays version of a pen gun it take about 5 mins and it can put holes and smash glass bottle it might give you ideas for an upgrade

He did it (author)2008-11-15

I used a cheap marker that was about 1 cm thick and I used 2 high tension rubber bands and a band to hold it and it went through my door!

bendog38 (author)He did it2010-04-14

 dont point that at anyone, even if you are just messing around.  Treat this like any other firearm.

bendog38 (author)2010-04-14

 I put a hole in my thumb with a modified version of this.  I even saw my bone and my life flashed before my eyes  (seriously, it hurt that much!)

JF196JF (author)2009-04-16

Not bad. perhaps an instructable on how to make ammo (not pen tubes, u only get 1)?

enjimann (author)2007-06-26

i always make these things when im bored at school and i find that instead of sticky tape use another rubber band to hold the rubber band on (its stronger)

Acer81996 (author)enjimann2008-11-28

Actually, string works excellent.

ray888j (author)enjimann2008-01-05

That is what i do

iluvrunescape (author)2008-08-23

this is the best instructable ever!!!! nice job + easy to understand:)

Mr. Chips (author)2007-04-30

I pulled the rubberband as far as it could go and the ink tube backfired ad hit my index finger. Really painfull, it stung for 3 and a half minutes

ray888j (author)Mr. Chips2008-01-05

I know ive done that before

zaro12345 (author)2007-11-26

As far as I know, it's spelled ballista. Not ballistra.

shadowg (author)2007-11-13

lol love the pi part

The_Reaper89 (author)2006-10-30

yeah i made em when i was in grade two i'm now in year 11. and sorry 'bout the pics. btw for highest strength try testing the makimum stretching length of the band against the length you can pull the cartridge before its end is out of the tube and tape in the right place for max efficiency.

I'm not sure i did it right because i used a Bic pen stuck the ink part in and shot it. But it left the part you write with and i was kinda kungfused but even if i did it wrong, it's awesome. ;)

Karim (author)The_Reaper892006-11-27

I took my mom's empty spool threads and put them onto the end of the gun and added other pen barrels and now it's like arifle version of yours

matt_the_awsome (author)2007-04-18

i wanna so badly pin my sis!!!i got this really big pen thing i could fit like 3cut up skewers in it!!

That Hurt This Time (author)2007-04-07

Theres gonna be a lock in at my school this week, so I pulled out my pen gun and got bamboo skewers and cut em into thirds and sharpened them, so now i have about 20 little arrows.

yellow elephant (author)2007-03-12

i gotta try this if its so strong.

thingygoboom (author)2006-11-18

put it through a popsicle stick and glue on an xtra holder put the stcik in the ground and fffffthunk, i got it further than my BB gun

RedGreen (author)2006-10-30

i love this design! i made one of these maybe 5 years ago. Shot it straight up in the air and killed a bird >_< in all seriousness, be careful with this will bury the ink cartridge in a tree, let alone flesh.

impossibble..... i need to make one if its as strong as u say.... lol

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