Pneumatic Pen-gun Project

[keep_it_real]

I was thinking about how to make an easy little pump for something like this and I figured out something cool. I'm not sure if this has been said yet though. A presta valve is basically a check valve. All you have to do is turn one inside out for the outlet and just attach another the regular way for an inlet.

Just get a presta valve and blow in and out of it and you'll get it.

This could also be used for a check valve inside a barrel sealing piston. They're really light.

[jackssmirkingrevenge]

I did some testing with half inch sections of nails with a masking tape tail, looks like much more effective ammunition than the lead shot. Target is a section of pine board.

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[Hotwired]

Good stuff

Pretty much like ball point cartridge darts but now they can actually fit. I don't think the lead pellets have enough mass to be really good projectiles.

[thrasmussen]

What's the size for the aluminum tubing?

[jackssmirkingrevenge]

the smaller one is 4mm i/d, 5mm o/d (the brass barrel is 3.5mm o/d so it needs some tape around it for the aluminium to fit snugly) and the larger one is 5mm i/d, 6mm o/d - your local model/hobby shop should stock these kind of sizes in 1 metre lengths.

[thrasmussen]

Thanks! As you can probably guess I'm thinking of making one myself just for the fun of it.

[A-98]

ok, i have to make this short.

first off: this is simply ingenious, ive already got a design layed out for mine, which is basically the same with some minor changes. i have also figured out a way to cram it inside a regular fine point sharpie. it will look basically the same. i was planning to build it last weekend, but i got my internet taken away from me for the rest of the year (i have a crazy dad, *sigh*) so i have to use school internet. ill see if i can upload from school laptops. i also got in trouble with school and blah blah long story short im not sure if i can build it for a bit. maybe this weekend.... i dunno.

i might be able to upload at friends house.

ive also figured out a firing mechanism, maybe, dunno yet.

i beleive my friend has a shock pump, so this is going to be a inexpensive project for me, good thing, cause im broke

ill be sure to PM you the pics first, cause after all, you are the inspiration for it! my friends are asking if i can make them for them. they have offered 40$$

second thing: you are amazing, definitely one fo the best. maybe im going to make a shrine...no wait, that would make me look crazy.... :tard:

[jackssmirkingrevenge]

Thank you all for the feedback. Anyone wishing to replicate the design and needs any pointers, feel free to PM me or ask here. I really, really recommend a high pressure pump - there's no worries about failure because it's all metal after all and on a small scale - and it really makes a difference to performance.

Still, maybe this is a little too small - I was thinking of scaling the design up a little to 6mm calibre and making an air-powered replica of the bicycle-pump 0.22 gun used in the film Munich (see attachment) - it would basically be an extended version of my original mini-piston design with a pump handle for a trigger and maybe an integral suppressor.

[Insomniac]

Hehehe you should make another one of these and fill the barrel with ink, then put a tiny bit of alfoil over the end of the barrel. Pressurise it and bring it to school/work/cinema. Fire it at the back whoevers head is closest.
'WTF JUST HAPPENED!!!!!!!'
"Errrm, my pen leaked...'

[bboymatty]

thats sweet. Id love to see how long the pressure could be maintained in that thing. Never know, might just be the next spy gadget hahah

[jackssmirkingrevenge]

I left it overnight at 300 psi, it was fine in the morning

[super spuder]

i told my friend at school about this thing, and now he wants me to make one for him so he can take it to school i need to figure out how to make one

[Hawkeye]

That sounds like great idea. Hopefully you can't figure it out.

[super spuder]

I can't now. Ok this is a funny story. I start out spudding last summer, Mom can i make a mini combustion, mom says "ok". Little bit later on. Mom, can i build a big pneumatic cannon. Mom says "ok". In the winter time (3 months ago) Mom, can i build a cannon using propane and oxygen to fuel it?, Mom says "ok" just lately, mom, can i build a golf ball cannon capable of launching a golf ball over 600 yards. Mom says "ok ". just last weekend. Mom, can i build a marble cannon. Mom says "ok" earlier tonight. Mom can i build a itty bitty pen gun that can only shoot through a piece of paper, Mom says "NO". i am lucky my mom doesn't go out in my shop hehehe. It will be easy to hide luckily

[A-98]

ah, dreamweaver class, able to get on internet!

i too have been contemplating scaling it up, but first i think i will cram it inside a sharpie and shoot my english teacher *cackle*

as for the scaled version, at my hobby store they have some brass pipe that looks to be 3/4", but im scared of using your epoxy methods cause i know it'll die . and the problem with using the one-size-smaller-sleeved method that you used on this one it will get expensive fast.

maybe ill make one that can fit inside an umbrella or ..Ooo! a crutch.
"i may look crippled, but dont try to push me over!"