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 49 users online :: 5 registered, 0 hidden and 44 guests


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

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], jimmy101, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Insomniac's First piston gun!!!

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

Insomniac's First piston gun!!!

Unread postAuthor: Insomniac » Mon Jul 21, 2008 6:23 am

After seeing some of the mini coaxials posted lately, I decided to get off my ass and make one.

I originally intended this gun to be fired via a schrader valve, and when it refused to fire I assumed the piston was at fault. After going through several pistons, I decided to try a bigger pilot. I stole a T and schrader from my ball valve gun, and attached a pvc valve I had laying around and tried it . IT WORKED!!!! :D Because of the unplanned modification to the design, the piston has loads of travel because the rubber bulb of the schrader no longer takes up part of the chamber, and there is loads of dead space in the T, but I think the pilot makes up for it :lol:

The noise from the T venting through the pilot is louder than the actual gun firing :lol:

The gun is made of threaded poly pipe and has a 6mm pen tube epoxyed into the brass cap. The reason for the funny adapter is so I could use a cap with threads on the outside, letting me glue it without ruining the threads. The piston is made of a small plastic bottle I had, chopped in half and with a bit of bicycle inner tube epoxyed to it (is it epoxyed or epoxied? Epoxied makes more sence, but then you are changing the name of the glue, which makes it incorrect... hmm.... :? )

After a few test fires the sealing face came off, So I am currently gluing it back on. I might switch the fill valve and the ballvalve around, so that if I look along the barrel I don't get a facefull of air, and possibly a piston if it manages to slip through the lip that stops it (not too risky, seeing as I always wear safety glasses) The piston lacks a bumper but other than somtimes getting stuck it doesn't seem to be a problem. I think what I might do is get some 6mm brass tube, and make the piston travel smaller, the barrel and chamber longer, and keep my over-the-top pilot setup. I'm using it at around 150+ psi, I pump as high as I can with the bike pump.

I will post pictures in a moment. I tried to a few minutes ago but spudfiles gave me an error and I lost my post :( So I'll post this now and then add pics.

The gun:
Image

Semi-expanded view, minus piston (is gluing)
Image

The massive pilot valve
Image

The piston. Very light.
Image

Image

Damage from a white k'nex bit at a wooden domino.
Image

This is the gun in it's intended layout, which was a failure due to insufficient pilot.
Image
  • 0

I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
User avatar
Insomniac
Major General
Major General
 
Posts: 1297
Joined: Mon Dec 18, 2006 3:47 pm
Location: Australia
Country: Australia (au)
Reputation: 0

Unread postAuthor: Carlman » Mon Jul 21, 2008 7:26 am

hey mate

there is no point me posting mine now then :( (jj it will be up)

i made one just like it but with a 3/8" qev as pilot but went on holls so havnt finished lol

nice job though :D
  • 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: Mitchza89 » Mon Jul 21, 2008 7:40 am

Nice mate, Very nice :D
  • 0

Image
User avatar
Mitchza89
Brigadier General
Brigadier General
 
Posts: 1056
Joined: Tue Jan 09, 2007 12:05 am
Reputation: 0

Unread postAuthor: Insomniac » Mon Jul 21, 2008 9:31 pm

This thing is starting to annoy me.... I need a way to stop the piston flying back into the T, and I also need a way of making the piston longer... it has sooo much travel and I imagine a lot of power is lost moving the piston... I tried putting some plastic to stop the piston going into the t, and another piston behind the main one to reduce the travel, but the pistons smashed right through the plastic. I tried again with better plastic but now the double piston setup refuses to actuate. I think I will have to cut a bit of metal in the shape I need to stop the piston entering the T, and find a longer piston.
  • 0

I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
User avatar
Insomniac
Major General
Major General
 
Posts: 1297
Joined: Mon Dec 18, 2006 3:47 pm
Location: Australia
Country: Australia (au)
Reputation: 0

Unread postAuthor: iisthemuffin » Mon Jul 21, 2008 9:46 pm

You could glue a washer on the insde of the tee connecting to the pipe. Or in the nipple connecting the pipe to the tee. That is assuming your using a nipple.
  • 0

User avatar
iisthemuffin
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 497
Joined: Sun May 11, 2008 2:38 pm
Reputation: 0

Unread postAuthor: Insomniac » Mon Jul 21, 2008 11:22 pm

The pipe itself is threaded, but I've found a solution. One of the pistons fits so well it refuses to come out one end of the pipe because of a tiny tiny lip at that end... like, really tiny lip. To reduce the travel I have glued up another piston that I should be able to put infront of it, reducing travel (It will be dry in a few hours). This way the current piston will basically act like a bumper.
  • 0

I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
User avatar
Insomniac
Major General
Major General
 
Posts: 1297
Joined: Mon Dec 18, 2006 3:47 pm
Location: Australia
Country: Australia (au)
Reputation: 0

Return to Pneumatic Cannon Database

Who is online

Registered users: Bing [Bot], Google [Bot], Google Adsense [Bot], jimmy101, Yahoo [Bot]

Reputation System ©'