Picture of Mini air-powered pen gun
How to make a small pneumatic gun out of a pen. It can be pressurized over 100 psi and shoot small nails into wood. THIS IS DANGEROUS if you choose to make this I am in no way responsible if you injure your self shooting it or if it explodes while your pressurizing it.

*I didn't know this but someone has already done a better job of a pneumatic pen on spudfiles thanks to Surfguy21 for this info
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Step 1: Parts

Picture of Parts
For this project you will need a bic pen and another piece of tubing (I got mine from a mechanical pencil) that fits inside the front peice of the bic pen if you remove the ink cartrige. You will also need a Zebra mini mechanical pencil (got from staples) or an eraser that fits inside a bic pen and you can drill a hole through. You need a schrader valve (the ones used on bike tires), and a airsoft bb.

Step 2: Tools

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All you need for this is a knife and some epoxy.

Step 3: Get the schrader valve

Picture of Get the schrader valve
The best way to do this is to get an old bike innertube and cut the schrader valve out, then sand off about 3/8 of an inch of the rubber off exposing the brass.

Step 4: Taking apart the pen

Picture of Taking apart the pen
This is really simple just disassemble the Bic pen and keep all the parts.

Step 5: Prepare the eraser

Picture of Prepare the eraser
ball and spring.jpg
All you need the Zebra pencil for is its eraser and spring. The spring is pretty self explanatory, just bust apart the pencil and take the spring out. The eraser will serve as a seal it will go on the end of the larger tube (not the ink cartridge) and be sealed when the airsoft BB touches it. In the drawings pink is the eraser.

Step 6: Prepare the end cap

Picture of Prepare the end cap
ball and spring.jpg
This step is a lot like the eraser step just cut off the end cap of the pen so you end up with a plastic tube.This is the black part in the middle of the drawing.
da_mann4611 months ago
Could u make this in a video cuz i learn by watching a listining not reading pls it would help me a lot
theegghead11 months ago

this looks cool but I can't grasp how you fire the thing do you press down on the top of the barrel? Or do you pinch the barrel then push inwards?

ramicaza3 years ago
wow really cool how you actually made it out of a pen. I had an old one made from a marker but the 4mm barrel crumpled at 170psi :D... lol i made a new metal one though, and posted that here.
mafzal23 years ago
And now I am grounded for shooting my brother with this gun.
Rehtes3 years ago
dude nice blade
stop spamming, nobody cares.
improyo3 years ago
what do you glue the eraser to???? is in the ink cartige
sabladask4 years ago
see my instructable, i made a spring powerd piston bb gun.
good build
Dreistein4 years ago
a mini pellet gun
ilpug4 years ago
this is just a mini piston cannon. but very dangerous.
eel laup5 years ago
that is very clever can u make a pdf url so non pro members can download
make six, put them into a cap gun cylinder XD that would be soo cool
iTraceur5 years ago
Erm, I'm probably confused with the drawings, but when you push the trigger in, wouldn't it fire and hit your finger? I know I'm wrong, so could someone kindly explain, WHAT THE HELL?!
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Personally, i just like showing off, so freerunning.

But i admire and appreciate the dudes who actually put backflips and 10m jumps into good use.
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Why do you hate freerunning?  And how the hell is parkour more 'peaceful'??

Oh, and i'm not american.  And, how old are you?
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Ok, i'm not going to bother arguing with you about parkour not being a martial art.  But you didn't answer my 2nd question: how the hell is parkour more 'peaceful'?!
what exactly is the difference.....

and this is a simple co axial piston cannon. when you push the scrader valve it lets air out, the pocket of air behind the piston becomes less pressureized. then the pocket of air around the barrel pushed back the piston and takes the path of least resistance, out the barrel.
Jor2daje (author)  absolute zero5 years ago
No, this uses a mechanically actuated piston, instead of relieving pressure from behind the piston you manually push the piston back using the inner barrel. I know a coaxial would be more efficient but I built this before I learned about pressure differential actuated pistons
not sure why i didnt get a message about your response.
But i was just looking back at this because my co axial mini isnt sealing, but i just notices that it isnt what i thought....
I think ill use this design if i cant get my piston to seal, trying to remove a ball pump as my exhaust valve(i dont actually have a schrader atm) isnt working very well...
do you go to anger classes
I think the idea is that you push the barrel inwards, by gripping it on both sides with two fingers. In other words, you don't have to put your finger over the end of the barrel to push it inwards. hopefully this helps LG
Nice name. Right. Guess that's why it's called a co-axial pengun then... It'd be 10 times better to have the button on the side though... TO THE WORKSHOP! Oh, hang on... TO THE PENCIL-CASE! QUACK!
thank you. the name refers to my inept gaming skills .......... btw, good luck making the pen gun, I would like to make one, but I don't nearly have enough skill to do so. LG
Meh, strike that side-button-pen-gun. Too hard to seal it off. Ok, new idea - you know those pens that rotate at the back, with a little mechanism in the middle that pushes the ink tube forward? Turns out they're really easy to seal off, and I've got a nice-looking one... BACK TO THE PENCIL-CASE! Oh, and relating to your pen-gun making skills (Or, rather, lack of), Who really cares? Is there anyone on this site who can say they studied for a degree in 'Pen-Gun Making'? QUACK! (iTraceur, PhD, D. Psych, PgMD)
good ible accept i didn't see where you got the 1st barrel from, the one that goes on the outside of the ink cartridge.
Ben Nguyen5 years ago
OMB I think I'm gonna try this.
which specific pencil did you get the "larger tubing" from? i wanna build this so bad....! awesome... faved
Jor2daje (author)  MadBricoleur5 years ago
Instead of building this design, I would try the gun jsr made that I linked in the intro. I made one based on that design and worked even better and is capable of much higher pressures.
Wambotrot5 years ago
I just don't get it.
i see what your saying. jrs is piloted from behind, while this is activated by a protruding out the front inner barrel. either way if you activated the shrader it would act just as jsr's. potato patato in my opinion, props for makeing it out of a pen. also, something like this could be modified into a rather more sinister auto injector. just saying, i dont really want to give that any more thought. cringe ick.
jamiespark6 years ago
really cool
JSR's pen gun is the same still though, cool
Surfguy216 years ago
Its called a co-axial pneumatic gun and the idea isnt his.jackssmirkingrevenge from came up with the idea of making it small and like a pen.You should give credit to him and all the other people that came up with the co-axial idea.
Jor2daje (author)  Surfguy216 years ago
Its different dude with a co-axial pneumatic you release a small amount of pilot air behind the piston that allows the piston to move backwards letting the air escape down the barrel. This gun has like a second barrel inside the other and you manually push the back. Also that gun was made out of copper and steel this is made entirely of pen parts. But I will agree that they did come up with a better idea before me.
O I see how it works now and sorry if I sounded mean before.Its a realy cool and concealable little gun.
Jor2daje (author)  Surfguy216 years ago
No problem, I definitely see the similarity between my gun and the one on spudfiles.
wow, very nice, but it could use a few things.... like a video of it working and more detailed instructions better quality pics but GREAT idea!
hoshi_neon6 years ago
this instructure is confussing... can u use the yellow box inside the pics ?
cheeseboy6 years ago
wow this is a new idea that I haven't seen before, I am definitely going to try this, good pictures too. Also it would be safer if you wrapped it in electrical tape so that if it exploded the shards wouldn't fly everywhere. 5.0!