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 64 users online :: 4 registered, 0 hidden and 60 guests


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

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

The Team
Administrators
Global Moderators
global_moderators.png CS

my mini won't fire

Discuss miniature cannons built from things such as pill bottles and pen caps.
Sponsored 
  • Author
    Message

my mini won't fire

Unread postAuthor: JDP12 » Sun Apr 15, 2007 9:37 pm

K I built my mini today, loaded it up, but it wouldn't fire!!!!!!!!!!1 :(

I have several reasons why it might not be firing

1) My chamber is 10 cubic inches, which seems pretty big

2) I may be putting too much butane in, my dad thought that I could never overfuel it. How do I measure how much butane to put in when it comes out as a gas??

3) The spark is SUPER SMALL, the two pin-points are like 1/4" apart, and the spark is even then really small, could it just be too small to ignite the fuel??

Okay does anyone have input, and any other reasons???

Thanks guys (and girls)
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: spudthug » Sun Apr 15, 2007 9:41 pm

maybe u did over fuel because if ur using a direct squirt of butane to the chamber it sometimes comes out fast.. try putting it in in little squrts...the gap should be fine for a mini some of mine are smaler... i really never had any luck from pins...if ur using push pins u may want to get some copper nails... i have had the best from copper nails....
  • 0

4" piston valved cannon-half done..( i spilt my cement...)

Hybrid- 75% done. need to build propane holder and drill/tap sparkplug hole..
User avatar
spudthug
Brigadier General
Brigadier General
 
Posts: 936
Joined: Mon Feb 26, 2007 9:02 pm
Location: johnsonburg, Pa USA
Reputation: 0

Unread postAuthor: JDP12 » Mon Apr 16, 2007 10:14 am

K. How would you set up a butane injection system?? I'm setting one up, but I am just wondering, when you ignite it, won't the combustion go into the butane tank part and possibly melt it??
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Mon Apr 16, 2007 12:03 pm

with small chambers, it's really important to get the right fuel mix.

I suggest you use a syringe coupled with a lighter refill can:

Image

works perfectly with my small volume cartridges, just fill the syringe to 4% of the total chamber volume and squirt it into the chamber.
  • 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: JDP12 » Mon Apr 16, 2007 4:41 pm

but wont it come out as a gas?? Or not because it is not coming in contact with air??

EDIT: To find that four percent do you calculate the volume of the syringe or do you somehow convert the cubic inches of the chamber to milliliters or whatever syringes are measured in??
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Mon Apr 16, 2007 4:54 pm

You fill the syringe as per the photo with the can upright, the gas will push the plunger out and you stop filling when it reaches the desired volume. If you squirt it directly into the chamber then plug it quicikly, no gas will be lost.

Your 10 cubic inch chamber is about 165mL, so 4% of that would be about 6.5mL, and that's the amount of butane you need in your chamber.
  • 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: JDP12 » Mon Apr 16, 2007 5:52 pm

aaaaah okay thanks a lot jackssmirkingrevenge, I'll try that and let you know if it worked or not. How should I prevent the butane from flowing out of the syringe before I am ready to inject it? Sorry, I know it probably seems like a stupid question, my mind just isn't rolling the gears right about now.
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: jackssmirkingrevenge » Mon Apr 16, 2007 5:59 pm

Don't worry, it won't flow out. Do a little experiment, fill the syringe with butane and leave it for 5 minutes. Then squirt it into a lighter. Whether you do it immediately or after a few minutes, you'll get the same size of flame.
  • 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: JDP12 » Mon Apr 16, 2007 6:01 pm

k thanks jackssmirkingrevenge, I appreciate the help.......now to convince my dad that less fuel is better in this situation...
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Mon Apr 16, 2007 6:13 pm

You can show him this to prove what 4% butane in a small chamber will do:

[youtube]http://www.youtube.com/watch?v=V4q8QJr412Y[/youtube]

Don't forget to vent the chamber properly with a blast of compressed air after each shot/misfire, to get rid of exhaust gasses and or unburned butane.
  • 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: JDP12 » Mon Apr 16, 2007 6:19 pm

holy crap, that's pretty powerful...K I went and tried to inject some butane into a syringe, but the plunger did not move... I am just using the tank from my lighter, it has a valve thingy that when you push it let's the butane out...but the gas did not move the plunger....is the pressure just not great enough in one of those?? I did just put some butane into the syringe though, and you're right it does not come out, I tested it with a match and almost burned my hand :oops: ..But do you have any theories on that??Could that butane tank from the lighter simply not have enough pressure?? That seems to be it...Where can I buy one of those butane cans?
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: iPaintball » Mon Apr 16, 2007 6:28 pm

You can buy thaem at wal-mart.
  • 0

User avatar
iPaintball
Colonel
Colonel
 
Posts: 695
Joined: Sun Mar 04, 2007 8:37 pm
Reputation: 0

Unread postAuthor: JDP12 » Mon Apr 16, 2007 6:29 pm

Is that in response to getting my plunger to move in the syringe or just what fuel to use Da Pneu Kid??????
  • 0

User avatar
JDP12
Major General
Major General
 
Posts: 1943
Joined: Fri Mar 30, 2007 8:34 pm
Reputation: 0

Unread postAuthor: gotbass7 » Mon Apr 16, 2007 6:45 pm

your using to much fuel and you probably have a bad mix. shake it and blow on it. this is probably already said but just in case...
  • 0

User avatar
gotbass7
2nd Lieutenant
2nd Lieutenant
 
Posts: 214
Joined: Fri Feb 02, 2007 12:43 am
Reputation: 0

Unread postAuthor: iPaintball » Mon Apr 16, 2007 7:30 pm

You asked where you could buy a butane refill can, so I told you. As for your plunger not moving, the refill can will provide sufficient pressure to move it.
  • 0

User avatar
iPaintball
Colonel
Colonel
 
Posts: 695
Joined: Sun Mar 04, 2007 8:37 pm
Reputation: 0

Next

Return to Miniature Cannon Discussion

Who is online

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

cron
Reputation System ©'