SpudFiles

Well guys, It's been a few years since I posted any of my cannons and even so, a large majority of the guns I have built have never even been photographed. So pretty soon, I will be making a few different threads to show you guys what I have been up to for the past year.

As the topic states, this pengun is designed to be used at high pressures under 1000 psi. While many penguns are made of thin walled hobby tube that can only handle so much pressure, I used 1.5 mm thick high pressure brass tubing that i got from a local contracters supply. It is rated to about 3500 psi so there is no danger of it failing.

On this particular pengun I decided to the more advanced route and machine the piston out of solid aluminum rod. The piston has an oring and as far as I know, the smallest piston check valve ever built. The piston alone took 4 hours to make and it was tedious work, but I'm very pleased with the results. To make the check valve, i had to take a .5 mm drill bit and drill all the way through the piston, about 1mm from the edge. Then i took a 1mm drill bit and drilled 2 mm into one side of the hole. Next, I took a 1mm nail art ball and put it into the hole and glued a very small rubber washer over the top and it created my sealing face as well as the end of the valve.

I'll have a video up soon, as well as pictures of the piston, but for now here are a few to give you a general idea of what the pengun looks like.

nice, whats the caliber how did you connect the schrader valve? cant see any solder

-_- wrote:nice, whats the caliber how did you connect the schrader valve? cant see any solder

It is 3mm in caliber and I used clear epoxy because it looks better than solder and is quite strong.

Looking good, let's see some action videos

Wow just after looking at this, it takes me back to when I made my second working pengun. I was really proud of that one but compared to this one right now it looks like crap. Btw jack, what's the highest you have taken your penguns up to?

My original would leak beyond 200 psi, but I took the V2 happily to 800 psi.

nice clean looking pen gun. but we realy have to see some damage, no matter how small

for the check valve on the piston a floating oring would have been much easier and faster. also a HDPE or nylon one would be ligher and faster but would it make a difference in something this small? prolly not much

also im pretty sure that normal thin wall brass can hold that much pressure...

yeah its so small that it can be almost enything . but good looking gun, if i would been you i would solder the schrader because i think it would be more safe in high pressure, thats just waht i think

Making a check valve on such a small piston would have been easier just using the sealing face as a check valve, but nice job. Love it!

c11man wrote:nice clean looking pen gun. but we realy have to see some damage, no matter how small

for the check valve on the piston a floating oring would have been much easier and faster. also a HDPE or nylon one would be ligher and faster but would it make a difference in something this small? prolly not much

also im pretty sure that normal thin wall brass can hold that much pressure...

Originally I was going to make it a floating o-ring design, but i ended up making the groove to tight and couldn't get the o ring off So i opted to just leave it on and make a nice check valve instead.

this is something very very cool, looking forward the new photos!

Is it serviceable?

AAARGH!! Need damage pics!
I wouldn't have the patience to work with something as small as a pen-gun.
Jsr's pico-ax is even more terrifying tough.

As stated before, I know how eager you all are for the damage pics and I will have them up tomorrow. I promise

if you dont, we call to dirty harry and then lets see who is giving those photos