Pneumatic Pen-gun Project

Miniature guns are novelty custom, unique, and sometime downright crude! Common construction materials often include pill bottles or pens. Show us your work!
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Thu Apr 26, 2007 1:52 pm

Is this the smallest co-axial pneumatic yet?

Construction is all metal, with the main chamber being the 6mm I/D brass tube I normally use as a barrel for airsoft launchers. The barrel is 5 inches long, which set the dimensions for the rest of the device, end result is something a little longer than your average pen but not too far off. The barrel is 2.5mm (0.098") caliber, unfortunately the closest lead shot I have is 2mm wide so I need to use tissue wadding.

No chrono results yet, so far I've tested it to 400 psi, at which point it developed a small leak so I repaired it and limited myself to 200 psi for now. Still, high pressure testing is on the cards some time in the future :D

Also on the agenda is a proper firing mechanism which will basically consist of a pin inside a pen cap that will allow the device to be fired by applying thumb pressure on the cap which will in turn open the schrader and pilot the piston.

Interesting in making something similar? Check out the how-to ;)

How it works:

Image

For more advanced versions, check out:

Pen Gun v2

Pen Gun Deluxe


A couple of videos (on their side, thanks to my technologically inept sibling :roll: ) :

Update 29/04/2007: Test at 300 psi with nail darts:

[youtube][/youtube]


[youtube][/youtube]


Update 27/04/2007: I improvised a cap firing mechanism by sticking a few airsoft BBs in the pen cap, it works! :D

[youtube][/youtube]


[youtube][/youtube]


[youtube][/youtube]


I'll let the photos and diagram do the rest of the talking:

Image

cutaway diagram

Image

parts before final assembly

Image

piston and breech closeup

Image

lead shot in vernier for scale

Image

"closed" configuration with cap over muzzle

Image

"open" configuration with cap over schrader
Last edited by jackssmirkingrevenge on Sat Feb 26, 2011 3:39 am, edited 12 times in total.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Hotwired
First Sergeant 3
First Sergeant 3
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK

Thu Apr 26, 2007 2:18 pm

:lol:

I had to watch those clips a couple of times because I couldn't tell if it had fired or not.

Excellent work making such a tiny launcher :)
Freefall
Private 3
Private 3
Posts: 49
Joined: Sat Mar 17, 2007 4:04 pm
Been thanked: 1 time

Thu Apr 26, 2007 2:24 pm

When I first saw the title, I read it as "Pneumatic penguin", and wondered what you were doing with small flightless birds. Then I clicked the link and all made sense.

Nice work, looks good. Have you considered using a presta valve instead of a schrader? You don't need a pin to depress a presta stem.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Thu Apr 26, 2007 2:24 pm

Yeah, the videos are shite, sorry. I'm trying to make some better ones as we speak.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Thu Apr 26, 2007 2:27 pm

Freefall wrote:When I first saw the title, I read it as "Pneumatic penguin", and wondered what you were doing with small flightless birds. Then I clicked the link and all made sense.
I know! I kept looking at the title from the corner of my eye while typing out the post, convinced I had written "penguin" by mistake hehe
Nice work, looks good. Have you considered using a presta valve instead of a schrader? You don't need a pin to depress a presta stem.
Thanks :) very logical suggestion... though can a presta handle the sort of pressures I'm likely to subject it to?
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
mega_swordman
Corporal
Corporal
Posts: 526
Joined: Wed Nov 29, 2006 2:37 pm
Location: Bay Area, California
Contact:

Thu Apr 26, 2007 2:47 pm

You're just full of ideas arn't you. Seriously, I need to state that you are a spudgun revolutionary. :notworthy:
"Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity." George S. Patton
User avatar
CpTn_lAw
Corporal 5
Corporal 5
Posts: 987
Joined: Sun Sep 11, 2005 9:10 am
Location: France

Thu Apr 26, 2007 3:00 pm

Do you have any idea of the muzzle velocity achieved by your launcher at 200 psi with a 2mm lead sinker?

BTW: very clean, very cool gun.
"J'mets mes pieds où j'veux, et c'est souvent dans la gueule."
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Thu Apr 26, 2007 3:08 pm

Thanks for the compliments :)
Do you have any idea of the muzzle velocity achieved by your launcher at 200 psi with a 2mm lead sinker?
I've given up trying to get a chrony reading, the projectile is too small and the chrony isn't seeing it :? ah well, as far as power goes, I can tell you it will go clean through a folded piece of A4 paper at 200 psi :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
super spuder
Corporal
Corporal
Posts: 558
Joined: Fri Apr 06, 2007 9:05 pm
Location: Ontario Canada

Thu Apr 26, 2007 3:41 pm

:lol: what drove you to make a gun that is soo small that it can only shoot through paper? not that i am saying it is stupid, i actually think it is quite cool.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Thu Apr 26, 2007 3:50 pm

super spuder wrote::lol: what drove you to make a gun that is soo small that it can only shoot through paper? not that i am saying it is stupid, i actually think it is quite cool.
Fair enough, I usually aim for high power, but felt like something a little different. Also, this is only 200 psi, I'm sure things will get a little better at 400...
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
super spuder
Corporal
Corporal
Posts: 558
Joined: Fri Apr 06, 2007 9:05 pm
Location: Ontario Canada

Thu Apr 26, 2007 3:59 pm

kool. i would never have the patients to fidle around with somthing that small :?
User avatar
lukemc
Corporal
Corporal
Posts: 565
Joined: Sun Feb 25, 2007 8:48 am
Location: NY

Thu Apr 26, 2007 4:06 pm

very cool! you should keep it loaded and in your pocket just incase someone wants to borrow a pen :wink:
"Those who are different change the world. Those who are the same keep it that way"
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26179
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 543 times
Been thanked: 319 times

Donating Members

Thu Apr 26, 2007 4:15 pm

super spuder wrote:kool. i would never have the patients to fidle around with somthing that small :?
give it a few years *chuckle*
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
rna_duelers
Staff Sergeant 3
Staff Sergeant 3
Posts: 1739
Joined: Mon Sep 26, 2005 7:07 am
Location: G-land Australia

Thu Apr 26, 2007 5:10 pm

Hahahah,a few year nice call..But this is really cool,look out you don't hit some one or yourself in the eye it would cause some damage.400 PSI!Nice what gas source are you using?
Image
PVC Arsenal 17
Staff Sergeant 3
Staff Sergeant 3
Posts: 1762
Joined: Mon Mar 27, 2006 4:18 pm
Location: United States

Thu Apr 26, 2007 5:16 pm

You've inspired me! Now I have no choice but to make one. Thanks a lot...
Post Reply