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 70 users online :: 4 registered, 0 hidden and 66 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

Build log for 1st High Pressure Pneumatic

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Build log for 1st High Pressure Pneumatic

Unread postAuthor: Novacastrian » Fri Aug 24, 2007 4:11 am

I love combustions, but i wanted more power from a small chamber firing 12.7mm rounds.
I knew a pneumatic could do this under normal pressure, but with a large chamber. I asked a fellow member his expert opinion and he promptly sent me his idea for a 300 psi small chamber High Velocity Spud Accelerator.
I will post pics as i continue construction, here are a few to start with, the chamber with lfx sleeve, and the lfx piston with polyurethane integral sealing face.Image
Image
Image

I can't thank Jacksmirkingrevenge enough, and as he is as true Gentleman he gets full credit for this project, Thanks Jack :D
  • 0

Last edited by Novacastrian on Mon Sep 24, 2007 7:20 am, edited 3 times in total.

Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Fri Aug 24, 2007 4:34 am

I'm very impressed so far :)

In all fairness all I provided was a basic drawing:

Image

The interpretation of the drawing and choice of construction is all down to the builder - and that makes the difference. There are tons of good ideas out there, but if you don´t have the facilities to flesh them out, it's all they'll ever be.

kudos, keep it up :)
  • 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: wannabie » Fri Aug 24, 2007 4:58 am

looks good so far lol :P

what type of pipe are you using?
  • 0

In epoxy we trust.
User avatar
wannabie
Captain
Captain
 
Posts: 304
Joined: Sun Apr 15, 2007 11:44 pm
Location: Australia
Reputation: 0

Unread postAuthor: Novacastrian » Fri Aug 24, 2007 6:30 am

Pvc rod, machined to my specs :D I also use an internal sleeve of L.F.X. ,a self lubricating polymer.
  • 0


Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Unread postAuthor: Novacastrian » Thu Aug 30, 2007 4:18 am

I have just changed the piston to glass filled ptfe, the lfx one was too tight a fit, i also used softer polyurethane, so it seals better. pics soon....

Edit, i forgot to mention that the end cap with integral bumper is also complete, well iv'e gotta drill a hole out to place the schrader.
The poly is 55 duro, very good for this purpose. oh yeah and the whole gun will *weigh 600grm approx, the piston weighs 14 grams :twisted:

Edit edit, that *weight includes the silencer :P

Weigh is not a word

:cry:
  • 0


Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Thu Aug 30, 2007 4:33 am

Still keen to see the finished result :D
  • 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: Novacastrian » Thu Aug 30, 2007 4:39 am

Not long now Jack..... :twisted:
  • 0


Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: jackssmirkingrevenge » Thu Aug 30, 2007 4:42 am

Might I make one small suggestion for the silencer, if you're using multiple chambers I think a series of holes will work better than the slits you cut into the barrel of your 12.7mm combustion.
  • 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: chaos » Thu Aug 30, 2007 4:49 am

jackssmirkingrevenge wrote:Might I make one small suggestion for the silencer, if you're using multiple chambers I think a series of holes will work better than the slits you cut into the barrel of your 12.7mm combustion.


ill agree with jack here i have tried both slits and holes with baffles and the one with holes seemed to work a lot better.
  • 0

User avatar
chaos
Brigadier General
Brigadier General
 
Posts: 1205
Joined: Wed Jan 17, 2007 8:31 am
Reputation: 0

Unread postAuthor: wannabie » Thu Aug 30, 2007 4:49 am

Sounds better by the post :P I cant wait to see it, I wonder what kind of speeds you will get...

oh yeah there only seems to be 4 people posting on the thread... thats odd
  • 0

In epoxy we trust.
User avatar
wannabie
Captain
Captain
 
Posts: 304
Joined: Sun Apr 15, 2007 11:44 pm
Location: Australia
Reputation: 0

Unread postAuthor: Novacastrian » Thu Aug 30, 2007 5:04 am

Odd or not i will use your suggestion for the holes. i have the other barrel and it seems to port very quickly, it reduces db by approx 40 percent max.
Thanx for all the support...x4 :lol:

Edit: it sounds kinda stoopid but with the holes, would it change the frequency of sound disgharged by your gun, they could be tunable :twisted:
  • 0

Last edited by Novacastrian on Thu Aug 30, 2007 5:14 am, edited 1 time in total.

Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Thu Aug 30, 2007 5:07 am

Also for maximum effectiveness, why not have the silencer outer case shroud the whole length of barrel?
  • 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: MrCrowley » Thu Aug 30, 2007 5:13 am

On the subject of silencers, (note I don't helluva lot about the maximum effectiveness of them) couldn't you have a very effective silencer by doing what jack said, having the shroud the whole length of the barrel, and then what if you have a longer barrel then what you would have originally.

The wasted air wont shouldn't have too much effect on the velocity, so it would also be quieter and more effiecent then if you had a short barrel?
  • 0

User avatar
MrCrowley
Moderator
Moderator
 
Posts: 10207
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Country: New Zealand (nz)
Reputation: 4

Unread postAuthor: Novacastrian » Thu Aug 30, 2007 5:23 am

Jack, my dear friend, you have, have you not heard the story of the german
.22 calibre rimfire that is SILENT apart from the click.. i think you may have provided the link, YOU ROCK, i really like the idea, i will start brainstorming.
I would really like your help with ideas as i would other members :)
  • 0


Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Unread postAuthor: Novacastrian » Thu Aug 30, 2007 5:32 am

I'm designing a new "Flat Top" Silencer, it will be fat on the bottom and WILL require a pod, however it will allow aiming by eye, over the top of the barrel.
It will kind of look like a cam, with the barrel as the shaft.
  • 0


Novacastrian
Major General
Major General
 
Posts: 1604
Joined: Sat Aug 11, 2007 6:59 pm
Reputation: 0

Next

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'