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Posted: Thu May 03, 2007 11:29 pm
by jackssmirkingrevenge
I've been using epoxy for years now, never had a single failure due to adhesive, unless you choose to eat it as well I don't see how it could kill you.

The sleeving method would get expensive on a larger scale, which is why I use different construction methods like here and here for by bigger designs.

Posted: Sun May 06, 2007 8:11 pm
by bboymatty
Im just thinking here that you could probably make this a very nice semi auto gun with the use of a larger(ish) pvc or metal pressure tank and a regulator or something attached to the valve of the pen gun.

I know its probably too small for breech loading but if you could hook it up for semi operation that would be one hell of an achievement!

anyways, your gun is a shining example of ingenuity great work! And good luck too mate :)

Posted: Sun May 06, 2007 10:25 pm
by jackssmirkingrevenge
Cheers :)

Actually, I was thinking... what if I shorten it a little... looks awfully like a cartridge, doesn't it? :D

Posted: Mon May 07, 2007 3:26 am
by bboymatty
haha yeah i guess it does!

whats the range on this little guy?

Posted: Mon May 07, 2007 5:17 am
by Mr.Russ
this gun is soooo cool! i want to make one like exactly the same.. to shoot my tiny metal bb's

Posted: Mon May 07, 2007 8:27 am
by jackssmirkingrevenge
bboymatty wrote:whats the range on this little guy?
Range is across-the-room, the way its fired means its incapable of any real accuracy though the power is there (for the size).

If I made the body wider and shorter (and got a good deal on schraders in bulk :D ) it could be the basis of a pneumatic cartridge gun without the need for a separate air supply like my previous experiments.
this gun is soooo cool!


thanks :)
i want to make one like exactly the same.. to shoot my tiny metal bb's
The materials are simple enough to obtain and you don't need sophisticated tools, go for it :) would definitely recommend a 300 psi+ air source though.

Posted: Mon May 07, 2007 2:57 pm
by clide
Congrats on winning the mini division :lol:

Posted: Mon May 07, 2007 4:18 pm
by A-98
neat, i managed to build mine yesterday. im going to fit it in the sharpie tonight, and then work on making a standard ammo type. this is the fisrt piston valve i have ever made sucessfully, and now i want to make a bigger one. i have a pretty nifty idea for a 6mm barrel one. i discovered that the ID of 1/4 brass tubing is almost exactly 3/8", so im going to solder/epoxy some tubing inside that and make a mondo ish one.

right now im just trying to pump it past 325 or so, but i dont want to break my shock pump. im amazed by the power of something so small, but i wa to sqeeze more ou of it.

Posted: Mon May 07, 2007 10:49 pm
by jackssmirkingrevenge
clide wrote:Congrats on winning the mini division :lol:
Why thank you my good man - It was a long and arduous battle but *wipes sweat from brow* we made it in the end :D
neat, i managed to build mine yesterday.
Go on then, show us! :)

Posted: Mon May 07, 2007 10:54 pm
by frankrede
I should have made a mini for the contest!
A pill gun hybridXD
Nah a hybrid made out 1" steel with a 1/8" barrel.

Posted: Tue May 08, 2007 11:42 am
by jackssmirkingrevenge
I always wanted to make a tiny hybrid to use as a compact and powerful cartridge - small scale fuel metering is a bit of a [female canine] though...

Here's a design I had posted on spudfiles:

Posted: Tue May 08, 2007 11:46 am
by A-98
well, mine was working beatifully, 40' of range and still able to go a couple mm into wood. i made 5 finish nail darts, with string-feathers for drag, they worked gret.

however, all of a sudden i noticed that air was leaking out of my barrel. by this time i had crammed it into a sharpie, so i to force it out by pushing on the barrel this cracked the epoxy and the barrel slid around. i tried to repar this and the leak at the same time by cutting it about .5" away from the front and splicing in some 1/4 pipe. by the time i was done with al this i had completely killed it and had to start over, i removed the o-ring and had to put the shrader/tubing part in my stove to burn off the epoxy.

i have now started over again, and i think this should be better than the old one. unfortunately sharpie is a bit shorter than your model, so its not as powerfull.

i was wondering if you have any tips on epoxying the barrel in. i have been taking a small peice one size bigger than thebarrel (1/8" and epoxying that on the barrel, and then epoxying that into the sleeved area. im a bit suspicious of this as being the cause of the leak last time.

im going to a friends house this weekend so i can make one for him, and grab some more tubing and shraders if i can make any reasonable quantity of "cartridges" ill make a pistol/rifle and if i feel lik egoing crasy i might go for a belt fed machine gun.

once again, sorry for any typos, i have to typethis during english class, so i cant check it.

Posted: Tue May 08, 2007 11:52 am
by A-98
hmmm...cant edit my posts.... must be 'cause of the competition...

also, ill try to get pics up when im at my friends house. just a teaser: then i unscrew the back (cover for shrader) and push the cap on it pops up a tiny red button. when you push the button it fires, and at anything above 150 psi blows the cap bach onto my finger, resetting the button so i can just slide it back on the front.

i have only gotten 7 hours of sleep in the last 48 hours cause of this. :D

Posted: Tue May 08, 2007 12:20 pm
by jackssmirkingrevenge
Are you sure you're preparing the surfaces to be epoxied well? and mixing the epoxy in the correct ratios? Epoxy only works well if you respect certain conditions.

Looking forward to seeing your pics :)

Posted: Tue May 08, 2007 2:36 pm
by A-98
yup, using JB-weld, quick type (cause im too impacient). i dont have a file small enough to roughen the insides of the tubes, but i used a coarse sand paper on the outsides. it want a casual press that moved the barrel, i had to press down with quite a bit of force.

ive been daydreaming about the possible use of the cartridges, and ive decided to go with a bolt action, but i need to figure out how to open the schrader. i was thinking of a spring inside of the bolt that would be released by the trigger acting like a hammer valve. i need to get back home and get scratch paper and plan this. i would love to make a belt fed design tho :?