Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 60 users online :: 3 registered, 0 hidden and 57 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

New to this, just made two spud guns, holes in .5" plyw

Post questions and info about combustion (flammable vapor) powered cannons here. This includes discussion about fuels, ratios, ignition systems, safety, and anything else relevant.
Sponsored 
  • Author
    Message

New to this, just made two spud guns, holes in .5" plyw

Unread postAuthor: kiwi of nitro » Mon Sep 01, 2008 2:05 am

I race nitro RC truggies, and one day I left a few head shims out of my engine after a rebuild and it caused detonation to occur in the combustion chamber (fuel and air mixture explodes rather than burns which damages engine), it blew the glow plug out of the head button with a gun shot like sound when I hit the throttle destroying my glow igniter which was on the glow plug at the time.

Anyway, it made me start thinking about building a cannon that operated like an engine. (igniting a mixture of fuel and air with an electric charge and using the energy released to drive a projectile rather than a piston).

So I went to Home Depot and started buying a bunch of piping, fittings, cements, sealants, and a piezoelectric igniter.

Built two guns, I have a video of me using one of them.

Click here for video of small spud gun.


Image

Daiwa sticker :roll:

Image

Used RTV and screwed the igniter into a 5/8" hole in the tee joint. That's 1.5" barrel and 3" chamber.

Image

Igniter leads run inside the chamber and come through a small hole where they are attached to 2 large bolts that create the spark in the chamber.

They are attached to the bolts with hex screws.

Image

Image

That wire in between allows me to adjust the gap.


NOW FOR CANNON #2 THE WHOPPER!!!


Image

That's 4" chamber and 1.5" barrel.

Image

I made the igniters removable by bolting them on and then sealing them with rtv.

Image

The spark jumps to one of 8 prongs on part of what was the gas concentrating vortex that came with the igniter, it is suspended by a small cable from an old dremel snake.

Image

Notice the stopper in the barrel, that is present in both my guns.

Image

Nitro cleaner is pure methyl alcohol, my favorite fuel.

Image

This target was shot from about 60 feet away with the whopper, this picture shows the back side of it, it's a half inch of plywood.

Image

a couple shots hit the wheel barrow

Image




Those are my cannons



-Matt
  • 0

User avatar
kiwi of nitro
Corporal
Corporal
 
Posts: 77
Joined: Sun Aug 31, 2008 9:42 pm
Reputation: 0

Unread postAuthor: starman » Mon Sep 01, 2008 2:46 am

Fairly decent guns here. The duct tape takes away from the look of the gun. I can't imagine why it's necessary for it to be on there. Next time, design your build without including using duct tape anywhere on it.

Also, your spark gaps seem more complicated than they need to be. It isn't necessary to use the gap bracket/holder that comes with the BBQ ignitors. And, how does the wire between the bolt heads allow you to adjust the gap?

I've used methol alcohol with a little nitro methane mixed (RC fuel) as spudgun fuel before and can attest it works well for a spray and pray gun. Your next gun however, you should plan to move to metered propane.

Good effort though and Welcome to Spudfiles!
  • 0

User avatar
starman
Donating Moderator
Donating Moderator
 
Posts: 3041
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC
Reputation: 0

Unread postAuthor: ALIHISGREAT » Mon Sep 01, 2008 2:53 am

nice cannons but that pipe doesn't look pressure rated, for your next i would use pressure rated because 1. its pressure rated so safer (duh!) 2. it looks better because its smoother and less angles, cluttered, indented or whatever.
  • 0

<a href="http://www.bungie.net/stats/halo3/default.aspx?player=ALI H IS GREAT"><img src="http://www.bungie.net/card/halo3/ALI H IS GREAT.ashx"></a>
Image
User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: CasinoVanart » Mon Sep 01, 2008 6:08 am

Silastic is good!
  • 0

User avatar
CasinoVanart
1st Lieutenant
1st Lieutenant
 
Posts: 281
Joined: Wed Jul 30, 2008 1:10 am
Reputation: 0

Unread postAuthor: TurboSuper » Mon Sep 01, 2008 9:10 am

That's a cool cannon. It seems to be made of ABS, which is great for added safety. I also thing the duct tape compliments it's "ghettoness" quite well, in this case.

The ignition system seems a bit bizaare, but I guess if it works, then it's all good :D
  • 0

"If at first you dont succeed, then skydiving is not for you" - Darwin Awards

TurboSuper
Brigadier General
Brigadier General
 
Posts: 986
Joined: Thu Jun 16, 2005 1:44 pm
Reputation: 0

Unread postAuthor: frankrede » Mon Sep 01, 2008 12:39 pm

ALIHISGREAT wrote:nice cannons but that pipe doesn't look pressure rated, for your next i would use pressure rated because 1. its pressure rated so safer (duh!) 2. it looks better because its smoother and less angles, cluttered, indented or whatever.
Your point is? I would think someone with over 1000 posts would think more.
This is a basic combustion, NSF-PW isn't really that necessary.
  • 0

Current project: Afghanistan deployment
User avatar
frankrede
Lieutenant General
Lieutenant General
 
Posts: 3220
Joined: Thu Jul 20, 2006 9:47 pm
Reputation: 0

Return to Combustion Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot]

Reputation System ©'