SpudFiles

Hey guys, first post here, so forgive me if I manage to screw this up!

Anyways...I’ve been making potato guns for quite some time now (about 6 guns over the course of a year...maybe a bit longer)...anyways, figured it was about time to make a mini pneumatic, so here it is.

<img src="http://img139.imageshack.us/img139/8673 ... opy8ij.jpg">

As you can see in the picture, the gun is pretty simple…A small handheld bike pump is connected to the chamber via a short length of pressure hose which is connected to the Schrader valve…

The chamber is 20” of 1.25” PVC with a pressure gauge screwed into the end cap so I can get consistent shots at about 45PSI, or about 5-6 pumps.

A 1.25”-.5” bushing (connected to the barrel with a coupler) has a short nipple from the half-inch side which leads to a half-inch ball valve. (ill talk more about this shortly)

Lastly, the barrel is just about 10” of 1 inch PVC which conveniently fits perfectly on the outside of one end of the ball valve. (The length of the barrel could almost be doubled, and work even better, but the short barrel is just more convenient)

Ammo is simply balled up paper with tape wrapped around it to form a sort of teardrop shape, and these can shoot approx. 50’ at 35PSI, and are great for indoor use.

Back to the ball valve I mentioned earlier, I simply removed the plastic grip from it, and then drilled a hole in the very end using a 3/16 bit. Then, I I screwed a long, thin screw about 1/8 of an inch into the hole, to serve as a handle…To use, turn the valve on the side grab the screw, and pull back sharply…

Using this in lieu of a normal ball valve I’m able to open it significantly faster and easier than I would normally be able to, and have noted increases of approx 15’ when using it




Anyways, I’m looking for some CONSTRUCTIVE comments...ideas on how to make it work better or opinions from the other members...Really anything that isn’t "OMG THAT CANNON IS AWESOME/TEH SUCK!" or "OMG GO GET URSELF A PAINTJOB AND ULL BEE IN BUSINESS!"

Two little side notes before I post this:
- I'd have posted the rest of my cannons, but currently, this is the only one that i have that it small enough to fit thru the door into my room, where my webcam is
- This post was not only meant to show off my gun, but also as a tutorial for a cheap simple and effective pneumatic, and if the mods deem it worthy, I’d love to have it posted as such.

It may look good, but it have a very bad power to lingth ratio.Much smaler ball valve pneumatic can be more efective.

i know that this isnt the greatest gun...was never supposed to be... i didnt want to make anything that required more than 20 minutes of work, and that i could make with parts that i (or anyone who wishes to build a small gun) have

as to "power to linght ratio"
spelling's always nice =) care to retype linght?

assuming that what you were saying was length, the first paragraph answers that.
not only that, but considering the whole thing is about 3 feet long with the barrel, it equals, or outperforms quite a few of the guns that i've seen that are this simple...On top of that, had i made it smaller:
A. there would not have been able to mount the pump, or the pressure guage directly onto the chamber
B. the Chamber would be so small, that t he pump would be inadequate to fill it to even 20 PSI

Anyways for gun that shoots balls of paper around my house, it works perfectly...it was just a quick project aimed for fun, not effeciency


hope that cleared up my reasoning for not making it as compact, and optimized for its size, as you'd expect

I didn't think that Rambo was insulting your gun, I think he was just pointing out that for it's length it might be quite inefficient. But seeing as he's from Romania and he makes some pretty sick combustions, we tend to give him a lot of respect.

I can understand why he said your cannon wasn't efficient, 1.25 in by 20 in chamber and a 10 in by 1 in barrel. As you mentioned above, you weren't going for efficiency so my whole rant was worthless.

It's a nice cannon, and that's all that matters if you have fun with it.

I liked that first post too, very well thought out, and I think one of the only first posts here that has used correct spelling and grammar! Welcome to the forums.

He's from Bulgaria, I'm from Romania.
I'm done being offtopic
Nice cannon, BTW. I'd make a rifle stock out of wood and mount it on it.

I admit that you guys are right.The most inportant thing is the fun.Next is the efficency and user friendly.My guns may be with good power to weight ratio, but to shoot them I must fill H2O2, put KMnO4, put an alkohol and all that in a gun that is all hold with tape.Very unpleasent when it starts leaking .

drac wrote:I didn't think that Rambo was insulting your gun, I think he was just pointing out that for it's length it might be quite inefficient. But seeing as he's from Romania and he makes some pretty sick combustions, we tend to give him a lot of respect.

I liked that first post too, very well thought out, and I think one of the only first posts here that has used correct spelling and grammar! Welcome to the forums.

Well first off, thanks for the warm welcome, as for the spelling and grammer, i just i figured that if i was going to do my first post, i might as well do it right (plus, it's oh-so much easier to read than what you'd get in an AIM chat, which is a plus) But yeah, especially coming from the "forum nazi," thats really cool =)

Anyways, back to the topic at hand...Rambo, i have seen a few of your guns, and let me take this moment to say that they are some of the nicest that i've seen... I was never really much of a Combustion fan (no pun intended...)because the simplicity and power of a pnuematic always made me lean away from them...

on a side note, my shop teacher and I are making a hybrid...he provides the materials and tools and some experience, while I provide the ideas and some know-how...Definetly a GREAT in-class project, wouldnt ya say?

OK..back on track...
Rambo, like you said

Rambo wrote:My guns may be with good power to weight ratio, but to shoot them I must fill H2O2, put KMnO4, put an alkohol and all that in a gun that is all hold with tape

You have to go through quite a process to prep your gun for firing...and while i would not deny that its superior, 5 or 6 quick pumps of the hand-pump, will still win my heart...or something like that (you get the point, never the less)...Anyways, if i wanted effiency, I can just walk to my garage and shoot a piece of 2x4 through a stop sign 8)

FiveseveN wrote:He's from Bulgaria, I'm from Romania.
I'm done being offtopic
Nice cannon, BTW. I'd make a rifle stock out of wood and mount it on it.

I must say, that thats a good idea, except for two minor details...
1. no place to effectively secure it to, since the hose at the rear is very delicate...can't have that breaking
2. I've found that i can do quite an arnold impression by just firing from the hip (actaully, it fits perfectly in the crook of my arm, but it's still fun)

talk to you all soon
-zev