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The SEX (Scaled EXperimental) Pistol

Posted: Tue Dec 25, 2007 10:54 am
by dongfang
Hi,

Well it's been too long since I last presented anything here.

Really, I have something, but it is not finished yet ... but it's time to show the prototype!

The SEX Pistol is a DFTV based gun; valve housing is a 32mm tee. For an explanation of the DFTV and of the terms used, see http://antennalaunchers.com/dftv19/.
The main difference from the plain DFTV is that the exit disc and the vent disc are the same diameter, that the turbo disk has been omitted, and that the bolt is a pipe and is used as equalization hole.

This is really the same as the S-DSTV I once mumbled about; that was a pilot valve for conventional large barrel sealers. I simply added a barrel and a chamber, and then it became a SEX Pistol. Scaled, because I have a much larger scale-up of this in the pipeline .... (and I had it in the drain line too, if any of you read my story about how I blew up a clogged drain with it, that's it).

The PVC hose over the chamber end of the 20 mm pipe that centers the bolt/plunger is an RSCV (Ridiculously Simple Check Valve). It is the same as an old-fashioned bicycle rubber valve - a flexible sleeve over a hole in a pipe. The PVC hose around the pilot chamber end is a recompression damper - it seals pretty well against the vent disk seat and has some mechanical friction too.

The performance of this tiny thing (exit valve diam. is only 25mm, or 1 inch) is quite impressive. I'll see if I can get some damage done and post it later.

Regards
Soren[/url]

Posted: Tue Dec 25, 2007 11:02 am
by c19o
Very nice, what porting is your "meaner motta fokka version"?

Posted: Tue Dec 25, 2007 11:06 am
by dongfang
Hey,

50mm.

Regards
Soren

Posted: Tue Dec 25, 2007 11:13 am
by jackssmirkingrevenge
Impressive, what pressures are you running at?

Posted: Tue Dec 25, 2007 11:18 am
by ALIHISGREAT
ooh grey pvc goodness, i get the same colour in the uk, i think its EFFAST pvc... and thats a nice looking pistol and i'm curious as to what pressure you run at aswell. maybe to improve the looks you could use a smaller higher pressure chamber (not that it looks bad now :wink: )

Posted: Tue Dec 25, 2007 11:54 am
by dongfang
Hi,

Yeah I did think about a stubbier chamber. Or a 90 deg elbow.

I have no pressure gauge on it, but I'd say somewhere between 6 and 8 bar.
It can take more, but the threaded connection to the chamber starts to leak before that. I need to either replace the chamber (then if I cement the chamber on, the valve can not be used as a trigger anymore) or just improve the seal.

Regards
Soren

Posted: Tue Dec 25, 2007 12:09 pm
by hyldgaard
Very impressive. Did you built this in Denmark or Switzerland? not quite sure i understood where you normally live, as I have seen both countries mentioned as your location.

Posted: Tue Dec 25, 2007 12:20 pm
by SpudUke5
Very nice pistol :D

Nice job on creating the piston. I dont think i could do that. I would mess up somewhere.

Posted: Tue Dec 25, 2007 12:53 pm
by Novacastrian
Looks very fun to use, cant wait to see what it can do. I like the "Sex Pistol" name too, very original :)

Posted: Tue Dec 25, 2007 5:32 pm
by carter
looks super clean. nice name now can we see the damage

Posted: Wed Dec 26, 2007 1:39 am
by frankrede
<a href="http://s30.photobucket.com/albums/c325/ ... 11_9sl.jpg" target="_blank"><img src="http://i30.photobucket.com/albums/c325/ ... 11_9sl.jpg" border="0" alt="Photobucket"></a>

Posted: Thu Dec 27, 2007 8:01 am
by experament-u2
thats a nice looking gun chap
dont know why but i love the shape and nice job on the valve

great gun chap cant wait for the damage and the full scale version

Posted: Thu Dec 27, 2007 11:16 am
by dongfang
Hi,

As for the color: I think that's an EU regulated code color, so it should be pretty much the same all over Europe (light gray is waste water above-ground and orange is waste water underground. Black is ??? So much plastic plumbing in Switzerland is black, however Switzerland is not in the EU).

Heeey Hyldgaard, another Dane here! Jeg er dansker men bor og arbejder pt. i Schweiz. Pistolen er.... et eller andet sted. (I´m Danish but I live and work in Switzerland. The pistol is ... somewhere).

The best ammo I have found is pieces of 25 mm pipe with some tape wadding around them and ice inside. I will try do some damage pics with that. And maybe also with a 25mm barrel.

Regards
Soren