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 59 users online :: 4 registered, 0 hidden and 55 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

Combustion gun blowing cleanout off

This area is for the discussion of BB or airsoft sub machine guns, and or other small arms such as pellets.
Sponsored 
  • Author
    Message

Combustion gun blowing cleanout off

Unread postAuthor: devilman » Thu Jan 31, 2008 8:11 pm

Ive built myself a combustion bb gun, its a simple over under designe, it has a 90mm cleanout cap on it. the combustion chamber is 60mm pipe.

I spray some hairspray in there, put the cap on tight, and hit the ignighter. The problem is the cap comes flying out every time. Any one have any suggestions on how i can fix this problem, i carnt fire it till its fixed, cuz it hurts liek hell when it hits you in the arm :evil:

Edit- i have made 3 combustion cannons and never had this problem, they all used 100mm pipe
  • 0

Image

devilman
Specialist
Specialist
 
Posts: 42
Joined: Tue Jan 22, 2008 4:50 am
Reputation: 0

Unread postAuthor: OuchProgramme » Thu Jan 31, 2008 8:20 pm

Is the cap threaded? Or is it just a cap that you squeeze the chamber into.
  • 0


OuchProgramme
Major
Major
 
Posts: 371
Joined: Sat Jan 12, 2008 7:30 pm
Reputation: 0

Unread postAuthor: devilman » Thu Jan 31, 2008 8:22 pm

threaded cap of couse, and i twist it on tight to, and its still blowing it claen off the threads. The other thing is it hasent damaged the thread in the cap or on the chamber,

ill get soem pics if i can find the camra
  • 0

Image

devilman
Specialist
Specialist
 
Posts: 42
Joined: Tue Jan 22, 2008 4:50 am
Reputation: 0

Unread postAuthor: elitesniper » Thu Jan 31, 2008 8:25 pm

its beacuse your barrel is way to small for that chamber so when you ignite it the pressure goes out that small hole slowly so it just blows the cap off.
  • 0

User avatar
elitesniper
Brigadier General
Brigadier General
 
Posts: 1090
Joined: Sat Oct 13, 2007 8:40 pm
Reputation: 0

Unread postAuthor: devilman » Thu Jan 31, 2008 8:31 pm

Any way i could fix that problem? cuz otherwise i just wasted a fair bit of $ on stuff im not gonna use.

If i put like a hole or something in the combustion chamber to try and release some pressure, woudl that stop the cap comming off? Because here the only sizes they make threaded caps in is 90mm and 100mm. I have a reducer from 90mm to 65mm, or i could have done 100mm to 50mm
  • 0

Image

devilman
Specialist
Specialist
 
Posts: 42
Joined: Tue Jan 22, 2008 4:50 am
Reputation: 0

Unread postAuthor: mopherman » Thu Jan 31, 2008 8:35 pm

all your parts should be able to take the pressure of combustion in a closed chamber. scrap the back end and get a sch40 plug.
  • 0

searching for a modern day savior from another place,inclined toward charity,everyone's begging for an answer,without regard to validity,the searching never ends,it goes on and on for eternity
-Bad religion
User avatar
mopherman
Brigadier General
Brigadier General
 
Posts: 788
Joined: Sat Feb 03, 2007 8:20 pm
Reputation: 0

Unread postAuthor: devilman » Thu Jan 31, 2008 8:46 pm

What do you mean by a plug?

SOrry for the dodgy pic but i only have the web camatm, the missus has proper camra. This is what it looks like


EDIT- On another note, i have some small steel pipe (3/4) with a threded cap i could use, i just dont know how to get a spark inside of the metal pipe, ideas?

Image
  • 0

Image

devilman
Specialist
Specialist
 
Posts: 42
Joined: Tue Jan 22, 2008 4:50 am
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: sjog » Thu Jan 31, 2008 9:37 pm

Seal the cap end and fill it with air.
  • 0


sjog
Donating Member
Donating Member
 
Posts: 440
Joined: Sun Oct 15, 2006 9:43 pm
Location: Marthas Vineyard
Reputation: 0

Unread postAuthor: devilman » Thu Jan 31, 2008 9:55 pm

origionally i had the bb gun run of compressed air, but i got sick of pumping it after each shot, so i wanted to try and make a combustion one, less effort then.

I have changed all my pipes over to 3/4" steel, all i need to do is figure out how to make a spark inside of the steel, any suggestions?
  • 0

Image

devilman
Specialist
Specialist
 
Posts: 42
Joined: Tue Jan 22, 2008 4:50 am
Reputation: 0

Unread postAuthor: devilman » Fri Feb 01, 2008 7:32 am

Re-did the gun in all 3/4" pipe, and it was worse then bad. I could propell the lead bb further with my lungs then the combustion could (bb went maybe 1m with the combustion). The 3/4 pipe is just to small to use as a combustion chamber, it has no power what so ever.

So what size pipe should be used for the combustion chamber? should i just go 90mm thread to 90-60mm reducer, then another reducer down to my barrel size. Do this without added extra length with pipe, just enough to go into the fittings

Image
  • 0

Image

devilman
Specialist
Specialist
 
Posts: 42
Joined: Tue Jan 22, 2008 4:50 am
Reputation: 0

Unread postAuthor: OuchProgramme » Mon Feb 18, 2008 12:42 pm

Change it back to pneumatic :)

You dont have to pump it after each shot, just have a blowgun w/ a simple gravity fed magazine. Semi-Auto
  • 0


OuchProgramme
Major
Major
 
Posts: 371
Joined: Sat Jan 12, 2008 7:30 pm
Reputation: 0

Return to BB/Airsoft/Pellet Gun Discussion

Who is online

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

Reputation System ©'