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 53 users online :: 4 registered, 0 hidden and 49 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

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

Blowback Hammer valve : Build log

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

Blowback Hammer valve : Build log

Unread postAuthor: Leonard » Tue Mar 17, 2009 6:54 pm

Hello Guys!

Im opening this thread as a build log for a blowback hammer valve launcher. The design is pretty straight forward but as much as i know i have never seen it done without a lathe or machinery. I will be building this without any special tools (but with a lot of Epoxy!).

Here's the final design, to scale : 10 pixels = 1mm. Caliber of ammo will be 10mm. The grey in the drawing are areas that will never be pressurized at any point in the shooting process. Trigger not pictured.

<a href="http://s342.photobucket.com/albums/o434/22leonard22/?action=view&current=Design1.gif" target="_blank"><img src="http://i342.photobucket.com/albums/o434/22leonard22/Design1.gif" border="0" alt="Photobucket"></a>

I am waiting for parts from RCwings.com to come tru mail, more precisly the brass tubes needed to build the hammer valve. I have started to build the hammer, it is currently curing in my room. It might take a few days for me to update since im waiting for parts. Like JSR says : Watch this space.
  • 0

User avatar
Leonard
Sergeant
Sergeant
 
Posts: 93
Joined: Fri Feb 08, 2008 1:38 am
Reputation: 0

Unread postAuthor: POLAND_SPUD » Tue Mar 17, 2009 8:04 pm

wow you are the first person who draw their diagrams trying to keep everything up to scale

hope it will work... I am not sure if there would be enough pressure to reset the hammer... I am not into this kind of guns but it goes without saying that this is essential in order to make it work properly (maybe there should be some flow restriction for the first 1 or 2 cm of the hammer reseting movement after hitting the valve just in order to let it get more momentum... obviously the fact that you are using epoxy doesn't help here as this might require some serious tweaking


JSR posting in 5.... 4.... 3.... 2.... (naaaaaah he is sleeping in his bat cave... but if you manage to get it to work fine I am sure he will hug you long time ) :D
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: jackssmirkingrevenge » Wed Mar 18, 2009 1:04 am

POLAND_SPUD wrote:JSR posting in 5.... 4.... 3.... 2.... (naaaaaah he is sleeping in his bat cave... but if you manage to get it to work fine I am sure he will hug you long time ) :D


He was actually out getting hammered on Guinness, I'm as Irish as Mother Theresa but any excuse to drink :D

People have made auto hammer valves but yes, hugs are on offer :P

One thing which bothers me about this design is that the air pushing back the bolt is wasted, I would rather have a system that exhausts only through the barrel.

On that note, I've started on a tiny hammer valve auto myself that will look more like this, and in untypical style, will make extensive use of threaded fittings to be *gasp* serviceable :shock:

Bit of a tight schedule at the moment though, ah well.
  • 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: psycix » Wed Mar 18, 2009 4:50 pm

Blowbacks and hammer valves are quite the hype these days aren't they?

Not to discourage you, but I have the feeling that the hammer will not be pushed back enough.
And as this requires tweaking, tweaking and more tweaking, a threaded fitting to make things serviceable may come in handy.
  • 0

Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
User avatar
psycix
Donating Member
Donating Member
 
Posts: 3684
Joined: Mon Jun 25, 2007 7:12 am
Location: The Netherlands
Reputation: 0

Unread postAuthor: Leonard » Thu Mar 19, 2009 10:48 am

Dont worry, ALL moving parts will be serviceable. I know i'll have a lot of tweaking to do, so i prepared myself for this. I got a bunch of different springs ^_^. Also, the holes in the back of the hammer shaft (in wich air that push the hammer back goes tru) will be hand drilled, so i will be able to adjust the airflow until i get what i need.

Thanks for the comments!

As for this thread : I have not received the parts for the valve yet, but the hammer is finnished. I'll post the pics as soon as i can.
  • 0

User avatar
Leonard
Sergeant
Sergeant
 
Posts: 93
Joined: Fri Feb 08, 2008 1:38 am
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Fri Mar 20, 2009 12:05 pm

psycix wrote:And as this requires tweaking, tweaking and more tweaking, a threaded fitting to make things serviceable may come in handy.


Even I have understoon the importance of this, y'all are going to be so proud :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

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'