Logo
HomeForumCannonsWikiAlbumArchive
SpudFiles
Users  Rules   Search  Search   Chat  Chat   FAQ  FAQ   Memberlist  Memberlist   How-To  How-To   Other  Other
Register  ::  Log in Private Messages


Random Cannon

Recent topics
» Vacuum Balloon
by Lentamentalisk on 09/02/2010 22:09 PM

» Dragunovish rifle
by linuxexorcist on 09/02/2010 22:02 PM

» Big Stuff
by MrCrowley on 09/02/2010 21:56 PM

» Homemade or store-bought?
by Mr.Sandman on 09/02/2010 20:24 PM

» propane meter
by Grignacke on 09/02/2010 20:00 PM

» Good Deals Thread
by Gun Freak on 09/02/2010 18:30 PM

» Another Contest Idea...
by Ragnarok on 09/02/2010 17:55 PM



Donate

Hi Guest!
As you're not registered, some features could be unavailable. Click here if you want to become a member of SpudFiles
Username:    Password:      Log me on automatically each visit    

Post new topic  Reply to topic
Goto page Previous  1, 2, 3, 4, 5, 6  Next
 How-To: Make a pneumatic cannon with a 2" piston valve. « View previous topic :: View next topic » 
Author Message
MrCrowley
PostPosted: 04/14/2008 13:05 PM    Post subject: Reply with quote

Kaleun
<b>Moderator</b>

Joined: 23 Jun 2006
Posts: 7619
4936.83 Spud Bux

Hmm weird, mine completely thread together. Confused
Back to top
niglch
PostPosted: 04/14/2008 19:20 PM    Post subject: Reply with quote

Staff Sergeant
Staff Sergeant

Joined: 07 Jul 2007
Posts: 117
195.48 Spud Bux

MrCrowley wrote:
Hmm weird, mine completely thread together. Confused

I just bought some new parts to replace the ones I broke. The first is a 2" female adapter and the second is a 2" threaded plug. Both parts indicate that they are pressure rated & schedule-40 (NSF-PW). However, when I tighten them with my hands, the two parts only thread about halfway in before they lock up. Trying to force it in any more is what broke the last set of fittings I had. Is this ok or am I supposed to use some sort of lubricant when threading the parts together? I read online something about it being bad to over-torque PVC fittings so should I just leave it how it is?

Thanks.



fittings_2.jpg
 Description:
Here are the two fittings separately.
 Filesize:  62.11 KB
 Viewed:  186 Time(s)

fittings_2.jpg



fittings_1.jpg
 Description:
The fittings only thread together this far before locking up . . . :(
 Filesize:  55.41 KB
 Viewed:  192 Time(s)

fittings_1.jpg


Back to top
MrCrowley
PostPosted: 04/14/2008 21:28 PM    Post subject: Reply with quote

Kaleun
<b>Moderator</b>

Joined: 23 Jun 2006
Posts: 7619
4936.83 Spud Bux

Yeah don't over-torque them.

The fittings I used were a female and male threaded adapter. They completely threaded together with ease.
Back to top
clide
PostPosted: 04/15/2008 16:07 PM    Post subject: Reply with quote

Donating Member
<b>Donating Member</b>

Joined: 06 Mar 2005
Posts: 790
2301.84 Spud Bux

Fittings in the US shouldn't thread all the way together. The only ones I have seen that do have gaskets on them and aren't very common or are DWV parts.

PVC manufacturers typically recommend one to two turns past hand tight, and that seems to work for me usually.
Back to top
MrCrowley
PostPosted: 04/15/2008 21:43 PM    Post subject: Reply with quote

Kaleun
<b>Moderator</b>

Joined: 23 Jun 2006
Posts: 7619
4936.83 Spud Bux

Yeah that's a good point Clide. I'm using metric fittings.
Back to top
DaGrimRaper
PostPosted: 04/26/2008 20:39 PM    Post subject: Reply with quote

Private First Class
Private First Class

Joined: 23 Apr 2008
Posts: 32
80.87 Spud Bux

wow thnks dude.
Back to top
tony48
PostPosted: 05/04/2008 14:11 PM    Post subject: Reply with quote

Private
Private

Joined: 06 Apr 2008
Posts: 8
29.32 Spud Bux

Where did you get your barrel? I'm looking for a golfball barrel and I think I might have to go to a plumbing store to get one.
Back to top
JDP12
PostPosted: 05/04/2008 14:26 PM    Post subject: Reply with quote

Major General
Major General

Joined: 30 Mar 2007
Posts: 1470
1624.37 Spud Bux

www.bcarms.com

(message too short)
Back to top
THUNDERLORD
PostPosted: 05/23/2008 0:07 AM    Post subject: Reply with quote

Loose Cannon
Major General

Joined: 28 Mar 2008
Posts: 1301
3816.56 Spud Bux

Great How-To, Thanks MrCrowley.
Been thinking about piston design/ GB pistons and this will be very helpful.

Also with your system of having a seperate fill and exhaust pilot it looks like a way to add an auto-fill by leaving the fill attached.

I would like to design something similar with electric solenoids some time.
I read over the replies but didn't see any comments about that?
Back to top
MrCrowley
PostPosted: 05/23/2008 0:17 AM    Post subject: Reply with quote

Kaleun
<b>Moderator</b>

Joined: 23 Jun 2006
Posts: 7619
4936.83 Spud Bux

Yes, sometimes I leave my compressor attached if i'm shooting in the garage or driveway. I should've put a breechloader on it, maybe even a manual hopper*. Don't think anyone brought up anything like that, any questions just ask.

I'm in the process of building a new 2" piston golfballer for a school assignment, should be done in a week or two. I learnt a lot from this cannon, so i've made a few advancements in my new one. I could make it more powerful then it would be, but i'm limited by my assignment unfortunately. So I don't have 100% freedom.


*As in manual I mean that you need to do something to make the next golfball drop down, otherwise half of them will get sucked out in one shot.
Back to top
drunkii
PostPosted: 07/19/2008 8:25 AM    Post subject: Reply with quote

Private First Class
Private First Class

Joined: 17 Jul 2008
Posts: 26
67.79 Spud Bux

how much did that cost you ?:p
Back to top
MrCrowley
PostPosted: 07/19/2008 16:16 PM    Post subject: Reply with quote

Kaleun
<b>Moderator</b>

Joined: 23 Jun 2006
Posts: 7619
4936.83 Spud Bux

~$350NZD


Something like that
Back to top
jon_89
PostPosted: 11/12/2008 0:19 AM    Post subject: Reply with quote

Colonel
Colonel

Joined: 11 Apr 2007
Posts: 606
826.20 Spud Bux

I figured I ask this here instead of starting a new topic. I have read several topics of people using 1.25in caps and couplers as pistons. How well do these fit in 2in pipe?
Back to top
MrCrowley
PostPosted: 11/12/2008 2:08 AM    Post subject: Reply with quote

Kaleun
<b>Moderator</b>

Joined: 23 Jun 2006
Posts: 7619
4936.83 Spud Bux

In NZ I tried using them, all the same brand, but they were a few mm off.

I hear different brands have different outside diameters, so i'd recommend taking a small piece of 2" pipe to Home Depot and trying some 1.25" couplers out.
Back to top
jmccalip
PostPosted: 05/13/2009 17:09 PM    Post subject: Reply with quote

Staff Sergeant
Staff Sergeant

Joined: 12 Apr 2009
Posts: 111
341.70 Spud Bux

niglch wrote:
MrCrowley wrote:
Hmm weird, mine completely thread together. Confused

I just bought some new parts to replace the ones I broke. The first is a 2" female adapter and the second is a 2" threaded plug. Both parts indicate that they are pressure rated & schedule-40 (NSF-PW). However, when I tighten them with my hands, the two parts only thread about halfway in before they lock up. Trying to force it in any more is what broke the last set of fittings I had. Is this ok or am I supposed to use some sort of lubricant when threading the parts together? I read online something about it being bad to over-torque PVC fittings so should I just leave it how it is?

Thanks.


Yeah, just thought I'd add that anytime you see "NPT" thread(nation pipe thread), it means it's tapered. Like this:



I'm not sure exactly why they taper the threads. At first I thought it might be easier to insure a leak proof fitting in case of tolerance errors in the the manufacturing process. But I work in a machine shop, and NPT threads tolerances for our parts are +-.0005 on how far the gauge threads.

Pretty much any plumbing/air supply pipe or fitting you buy in America is NPT. I guess we have to do things different from you NZ and AUS folk. Laughing


Last edited by jmccalip on 05/13/2009 17:13 PM; edited 5 times in total
Back to top
Display posts from previous:   
Post new topic  Reply to topic Goto page Previous  1, 2, 3, 4, 5, 6  Next

Jump to:  



You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


SpudFiles Version 7.0
Template based off DAJ Glass Template by Dustin Baccetti
Photo Album Addon © 2002-2003 by Smartor
Powered by modified phpBB © 2001, 2005 phpBB Group