Page 2 of 4

Posted: Wed Jan 16, 2008 11:08 am
by psycix
Ragnarok wrote:Excuse me - lack of homemade pumps?
Well, thats ONE.
Still call it a lack. :)

I might be building one in some time but I will need O-rings im afraid and I have never used those yet.
But on the other hand its a nice project for me to learn how to work with O-rings.

Posted: Wed Jan 16, 2008 11:17 am
by Ragnarok
How odd. PCP airguns in modern warfare.

@psycix: There are others - I think SB15 made one, AliH is due to make one, BigJon recently posted about some difficulties he was having, and BTB is supposed to have had one try to relieve him of his front teeth.

IIRC, that's at least two working ones, two in progress and one that went wrong.
They don't seem to have enjoyed a great success rate, which might be what's putting some people off.

Posted: Wed Jan 16, 2008 12:09 pm
by ALIHISGREAT
@psycix: There are others - I think SB15 made one, AliH is due to make one, BigJon recently posted about some difficulties he was having, and BTB is supposed to have had one try to relieve him of his front teeth.
damn i got beat :( thet were all the things i was gonna mention now i just have to talk about nothing :(

Posted: Wed Jan 16, 2008 12:26 pm
by Brian the brain
ptfffft!!


I made one that was safe up to 79.9 bar..and tried 80 hahaha

It can be made safe, just make your own checkvalve out of an O-ring and a ball bearing.BB should be BIG enough to never get through the hole...


Ehhmm..it didn't knock my teeth out completely..it just loosened them...and split my upper lip in three places, broke part of my upper jawbone right under my nose, tear the gums off my front teeth :shock: ( still looks kinda strange) and somehow managed to give me two black eyes and a headache that would drop a Rhino!
...( edit: forgot to mention the chipped tooth..)I couldn't eat solid food comfortably for 3 weeks..

So don't go around telling people it knocked my teeth out..
That kinda talk scares people..:wink:

Posted: Wed Jan 16, 2008 12:49 pm
by ALIHISGREAT
^ oooh nasty i'm definitly gonna make my pump properly :shock:
(although 400psi is considirably less than 80bar :shock: )

edit: and if you are interested in mking one http://www.spudfiles.com/forums/pump-design-t12567.html

Posted: Wed Jan 16, 2008 3:39 pm
by clide
Hotwired wrote: Back to the pump though, with no check valve in the stem, the poor sod pumping it would have had to pull the piston up against a vacuum until the head reached the vent in the cylinder wall. Talk about uphill both ways.
It wouldn't be so bad, that pump head looks to be about 1 cm in diameter so the maximum force created due to vacuum pressure would be less than 2 pounds. I'm sure the friction was more significant than that.

Posted: Wed Jan 16, 2008 3:58 pm
by al-xg
Oh... that has scared me a little.
I was about to make a pump, hoping to achieve 50-70bar. (I have this design for a Girandoni rivaling repeating airgun.)
The check valve broke then, turning the pump into a ram ?
Did the handle actualy come right out or did it hit you because you were bent over ?


Oh and does anyone know what pressure the internals of a schrader valve would hold ?

Off topic... Has anyone seen the trailer for a film with that spudgunner gone evil ? Some kind of assassin using a silenced air cannon and draging a high pressure gas tank around ?

Posted: Wed Jan 16, 2008 4:07 pm
by Ragnarok
al-xg wrote:Off topic... Has anyone seen the trailer for a film with that spudgunner gone evil ? Some kind of assassin using a silenced air cannon and draging a high pressure gas tank around ?
No, I haven't... do you know what it's called?

I don't think Schrader internals should go much above 30 bar, and that's pushing it.

Posted: Wed Jan 16, 2008 4:27 pm
by al-xg
Something long... Like No country for an older man .... mmm well it had a few of those words in it.


Google found it...
But i saw a diferent trailer to this one... a little more gory and showing the cannon.

Posted: Wed Jan 16, 2008 4:33 pm
by MrCrowley
No country for old men.

New Coen brothers film.

The bad guy carries around a portable N2 tank I think it is, and has a cattle killer on the other end. You know those gun that shoot a bolt into a cows head, and then it retracts. Well he kills people with that.

He also uses it to knock out door locks, good movie, one of the best ever made.
<A HREF="http://en.wikipedia.org/wiki/Captive_bolt_pistol">This is what he uses</a>
Image

Posted: Wed Jan 16, 2008 7:12 pm
by al-xg
Mmm yes, the cannon is actualy a silenced shotgun... he just hold both at the same time.
Image
Turns out i saw the restricted trailer. And it seems it has been removed from a lot of places.

Posted: Wed Jan 16, 2008 11:19 pm
by MrCrowley
al-xg wrote:Mmm yes, the cannon is actualy a silenced shotgun... he just hold both at the same time.
Image
Turns out i saw the restricted trailer. And it seems it has been removed from a lot of places.
Wrong.
He has another cannon, which is the shotgun. I've seen the movie and he has the cattle killer and a shotgun, two different guns. The shotgun doesn't run off the N2(?) tank, the cattle killer does.

Posted: Wed Jan 16, 2008 11:26 pm
by jackssmirkingrevenge
cheers for that guys, that went straight to my downl...er... shopping list :D

Posted: Wed Jan 16, 2008 11:28 pm
by MrCrowley
Yeah the DVD rip is available onli.... I mean the DVD came out in the shops awhile ago. :roll:

Posted: Wed Jan 16, 2008 11:31 pm
by jackssmirkingrevenge
Here's me heading out to my favourite DVD store, Blockbuster :D