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 55 users online :: 4 registered, 0 hidden and 51 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

First cannon

Built a combustion cannon? Then post it here! This section is for completed, finished cannons that you have built. Please include pictures and information.
Sponsored 
  • Author
    Message

First cannon

Unread postAuthor: PythonWallace » Fri Nov 21, 2008 4:55 pm

Here is a small gun I made last week. I thought I was being original by making a spark gap for ignition, and for bending he chamber down around the bottom of the barrel, but after finding this site I see that I just did a poor job of reinventing the wheel.

The barrel is 38" x 1.25" and the chamber is 12" x 2" plus the bend. It's solid core PVC, sealed and reinforced with #8 x 1/2" wood screws, with a gloss black paintjob. The ignition is a piezo from a fireplace lighter, keeping the original triger, and has a 3/16" spark gap. The fuel is canned butane.

Now tear it up for me so I can improve on my next one.

Edit: dimension typos
  • 0

Attachments
100_1686.JPG
100_1686.JPG (30.92 KiB) Viewed 1835 times
100_1687.JPG
100_1688.JPG
100_1688.JPG (35.28 KiB) Viewed 1835 times
Last edited by PythonWallace on Fri Nov 21, 2008 7:49 pm, edited 2 times in total.

PythonWallace
Private
Private
 
Posts: 3
Joined: Fri Nov 21, 2008 4:42 pm
Reputation: 0

Unread postAuthor: Hydra » Fri Nov 21, 2008 5:04 pm

Great work for the first cannon.
Try a Pneumatic next, theyre harder, but stronger. The gun might be solid core PVC, but I dont think some of the fittings are solid. DWV (Non-pressure rated) pipe and pressure PVC pipe look different. I think someone else might tell ya.
DWV is fine for a combustion, but don't use it for anything other than a simple combustion cannon.
  • 0

User avatar
Hydra
Sergeant First Class
Sergeant First Class
 
Posts: 131
Joined: Sat Mar 08, 2008 11:58 pm
Location: New South Wales, Australia
Reputation: 0

Unread postAuthor: Ragnarok » Fri Nov 21, 2008 5:15 pm

Looks pretty decent to me, and cleanly built. I assume you've painted it?

- On a more powerful cannon, those elbows and reducers wouldn't be up to spec, but here, they should be fine.
- The chamber's size is about right for a metered fuel, but for a spray fuel, it may be on the slightly small size for the barrel.

And heck, half of what we do here is badly reinvent the wheel. Not literally, that would of course be stupid... "I know, let's make it a Reuleaux triangle instead!"
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: jackssmirkingrevenge » Fri Nov 21, 2008 5:21 pm

Nice done for a first cannon, especially the muzzle detail. You forgot the all-important damage pics though :)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: jrrdw » Fri Nov 21, 2008 5:22 pm

What? No mashed potato pics? If your going to reinvent everything, don't leave the damage pics out! :D

Welcome to Spudfiles.

Edit: Dam Jack, got me by a minute......
  • 0

When life gives you lemons...throw them back they suck!
User avatar
jrrdw
Donating Moderator
Donating Moderator
 
Posts: 6538
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Country: United States (us)
Reputation: 25

Unread postAuthor: Radiation » Fri Nov 21, 2008 8:02 pm

Great gun! Hey, if your comparing your gun to the great stuff on this site you're being extraordinarily hard on yourself. That's like taking your first steps as a toddler and beating yourself up because you can't do gymnastics.

Things you did well: Trigger, handle, solid core PVC coming up with a great ignition source with your own brain regardless of whether it's already been done, over/under design for shorter length and easier handling, support structure to stablize the barrel, and nice serrated barrel for cutting potatoes - one of the best I've seen!

Things I think you can improve: Larger chamber size to allow for metered propane, metered propane, increase the number of spark gaps, tap your holes on double thick walls rather than the thinner wall (with the exception of using lots of epoxy to reinforce the hole), larger barrel, chamber fan.

Really for your first post on this site this is very good!
  • 0

User avatar
Radiation
Sergeant Major
Sergeant Major
 
Posts: 183
Joined: Wed Jul 09, 2008 10:57 am
Reputation: 0

Unread postAuthor: starman » Fri Nov 21, 2008 8:38 pm

I agree with the rest, pretty decent cannon here. I like it a lot actually...nice and compact, light carrying. I don't see how or where you're getting fresh air in your chamber and injecting your fuel.

Your potato cutter (I assume that's what that is) looks really cool and different although I'm not sure it will perform any better than just a standard blade sharpened onto the barrel muzzle.
  • 0

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

Sponsored

Sponsor
 


Unread postAuthor: Carlman » Fri Nov 21, 2008 9:04 pm

Radiation wrote:Things I think you can improve: Larger chamber size to allow for metered propane, metered propane, increase the number of spark gaps, tap your holes on double thick walls rather than the thinner wall (with the exception of using lots of epoxy to reinforce the hole), larger barrel, chamber fan.


So basically your telling him to make it a bigger gun and use metered propane...

You did a great job mate, especially for your first. I can see that you will go along way in these forums and your now addictive hobby. Not to mention be great pals with Starman lol.

Nice work.
  • 0

Image
Aussie spudders unite!!
User avatar
Carlman
Major General
Major General
 
Posts: 1618
Joined: Sat Nov 24, 2007 1:18 am
Location: Western Australia
Reputation: 0

Unread postAuthor: PythonWallace » Fri Nov 21, 2008 9:12 pm

Thanks. I'm surprised it wasn't immediately ripped to shreds here. I have the parts to put a 3" id chamber on my next gun, but this uses 2" because that's what I had on hand. If I didn't have the parts already, I wouldn't have thought to make this, and I never would have found this site.

The beveled muzzle is to help cut the potato. I just made the small bevels, as apposed to a single bevel around the circumferance, for appearance. The supports are poplar. There is a 1/16" hole for butane spray, and the end cap isn't epoxied to the chamber. It has a tight fitting, 3" bolt/pin fastener for semi quick access to the chamber. I went today after seeing some of the designs on this site and bought a 2" to 1" reducer and a 1" ball valve to upgrade this.

I can't believe some of the potato guns the members here have made. I always thought most potato cannons were 6' sections of PVC with an endcap and a hole to ignite it with a lighter.
  • 0


PythonWallace
Private
Private
 
Posts: 3
Joined: Fri Nov 21, 2008 4:42 pm
Reputation: 0

Unread postAuthor: starman » Sat Nov 22, 2008 12:47 am

Carlman wrote: Not to mention be great pals with Starman lol.


Hey hey now, I resemble that remark... :wink:

PythonWallace wrote:Thanks. I'm surprised it wasn't immediately ripped to shreds here.


Nah it's pretty rare really, especially if you make an effort to communicate your ideas or questions in a reasonable way. You had some decent pictures, presented some critical detail and wrote in complete sentences and paragraphs....a decent sense of humor. You made real effort and it shows.
  • 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: jook13 » Sat Nov 22, 2008 12:56 am

Its tough to beat the portability and convenience of a solid combustion. As far as spray and pray guns go, this is pretty slick.

You sound like you have browsed this site a bit, so you know there is a LOT more you can do with this hobby. For a "first gun post", it sounds like there is a lot of interest here, I cant wait to see what else you can create.
  • 0

I like to play blackjack. I'm not addicted to gambling, I'm addicted to sitting in a semi-circle.
User avatar
jook13
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 434
Joined: Mon Jan 21, 2008 10:39 pm
Location: Prescott Arizona
Reputation: 0

Unread postAuthor: Radiation » Sat Nov 22, 2008 6:55 pm

Python, you did the exact same thing I did after posting my gun for the first time and getting all kinds if suggestions, I ran out and bought more stuff. :D the addiction begins! I can't wait to see what you do next!
  • 0

User avatar
Radiation
Sergeant Major
Sergeant Major
 
Posts: 183
Joined: Wed Jul 09, 2008 10:57 am
Reputation: 0

Unread postAuthor: nibbler125 » Sat Nov 22, 2008 7:37 pm

great cannon id just add a chamber fan
  • 0


nibbler125
Sergeant
Sergeant
 
Posts: 80
Joined: Sat Jun 07, 2008 10:42 am
Reputation: 6

Unread postAuthor: PythonWallace » Sat Nov 22, 2008 8:50 pm

nibbler125 wrote:great cannon id just add a chamber fan


I already have a fan with a momentary push button switch and an 8x AA battery pack hooked up in the 3" chamber for my next gun. I also have an old 100,000v stun gun I'm going to dig up for my ignition source. About that, do you normally use the trigger on the stun gun, because I was thinkin about using a momentary switch trigger wired to the batterys in it, and gluing the actual triger down so it's always on. I have a 2hp air compressor for airbrushing, so I'm thinking about tryin a pnumatic design, but I'm laid off so I can't do anything that costs any money right now.
  • 0


PythonWallace
Private
Private
 
Posts: 3
Joined: Fri Nov 21, 2008 4:42 pm
Reputation: 0

Unread postAuthor: starman » Sat Nov 22, 2008 10:25 pm

Just replace the momentary switch for the fan with a plain on/off switch. You'll want to run the fan for A) mixing air and fuel, B) during ignition..improves performance noticably, C) to assist in expelling spent gases after firing.

So basically you need to just keep it running most of the time while you're firing. This is why I am a proponent configuring a little beefier battery/power supply setup in the cannon.

I just used rubber bands to pin the stun gun's trigger down while switching power to it externally for firing. See the trip thunder ignition from the sig link below.
  • 0

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

Return to Combustion Cannon Database

Who is online

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

Reputation System ©'