Search found 16 matches

by userjjb
Mon Aug 20, 2007 6:00 am
Forum: Hybrid Cannons
Topic: Does 6x + a 20 foot barrel = Supersonic?
Replies: 26
Views: 5461

If I had to make a WAG on muzzle velocity, I'd say somehwere in the range of 1500-1600 fps from what I've seen out of similiar hybrids, and some rough models in GGDT based on your specs. We don't have much data from hybrids at higher mixes though, so we might all be suprised.
by userjjb
Mon Aug 20, 2007 3:01 am
Forum: Hybrid Cannons
Topic: Motorized tripod for Taternator II
Replies: 11
Views: 3864

I've followed this project for quite some time but I don't think I've ever complimented you, very nicely done! It's been very cool to see how the project has evolved. Also I couldn't help but notice I live very close by, I live over in Albany, NY. One quick question: on the record velocity shot quot...
by userjjb
Sun Aug 19, 2007 4:46 pm
Forum: Pneumatic Cannons
Topic: I've always wondered...
Replies: 34
Views: 5851

Re: I've always wondered...

Actually, it's the other way round. Steam is perfectly invisible with a refractive index of 1, but condensed water vapour is merely transparent, having a refractive index of about 1.3, which means it bends the light that travels thorugh. Humidity in the air is by a definition, steam - water in gase...
by userjjb
Sat Aug 18, 2007 12:21 am
Forum: Pneumatic Cannons
Topic: I've always wondered...
Replies: 34
Views: 5851

Re: I've always wondered...

snip>Water vapor is transparent to the naked eye <snip> Surely not as otherwise we wouldn't see clouds. Michael Actually water vapor is indeed transparent, what people typically call "steam" (for instance when water boils) is actually not vapor at all, but rather small condensed water droplets. Clo...
by userjjb
Fri Aug 17, 2007 9:15 am
Forum: BB, Airsoft, and Pellet Guns
Topic: my best cloud, new kind of internals
Replies: 32
Views: 14638

You would have been better off not even posting that video. Did you even fire the gun in it? I can't tell. Basically it's 3:30 minutes of boredom, you need to seriously edit it down to about 15-20 seconds; your gun is not so complicated that we need a 3 minute intro on how to load BBs and attach a b...
by userjjb
Fri Aug 17, 2007 8:54 am
Forum: Pneumatic Cannons
Topic: I've always wondered...
Replies: 34
Views: 5851

Re: I've always wondered...

Why is it that when I fire my pneumatic, I can't see any white "steam" come out the muzzle, but when I watch a video of the came shot, the camera seems to pick up the "steam"? It's been irking me for a while... :lol: I'm a little slow on the draw, but one reason not offered yet is that the CCD in m...
by userjjb
Wed Jul 11, 2007 6:39 pm
Forum: Hybrid Cannons
Topic: the JAUSH (in operational stage)[[[[UPDATES 28/3/2008]]]]
Replies: 36
Views: 14001

What grade of aluminum did you use, where did you get it from, and what was the approximate cost?
by userjjb
Thu May 24, 2007 11:19 pm
Forum: Pneumatic Cannons
Topic: Barrel sealing piston
Replies: 10
Views: 1999

thanks. its gonna be in a 2" tee and im using a 1.5" endcap with a neoprene seal as a piston. and ill be sure and post it. i need to get some damage pics of the cannon i built today after everything sets and then ill post it. look for some cannons from me over the next couple days/weeks Edit: oh an...
by userjjb
Tue May 22, 2007 11:27 pm
Forum: Pneumatic Cannons
Topic: Mach 1.6 Steam Cannon
Replies: 12
Views: 3688

Conventional burst discs are always a consideration too, the reason I didn't go that way at first was I figured it's be difficult to find a material that could stand up to the temperatures and pressures I'm shooting for (no pun intended). Light gas guns use scored steel plate with good results, alth...
by userjjb
Mon May 21, 2007 4:42 pm
Forum: Pneumatic Cannons
Topic: Mach 1.6 Steam Cannon
Replies: 12
Views: 3688

Interesting idea. 1. You don't know when it is actually going to fire. Never stopped anyone from making a traditional burst disk pneumatic. 2. If the chamber heating is uneven you may ( probably will ) get the solder holding the round melting unevenly. Really no reason to expect that the entire rin...
by userjjb
Sun May 20, 2007 9:01 pm
Forum: Pneumatic Cannons
Topic: Mach 1.6 Steam Cannon
Replies: 12
Views: 3688

I would suggest using threaded connections instead of brazing the end cap on, if possible. Lots of repeated heating/cooling cycles could eventually cause the brazed joints to fail. I'd use all threaded/flared connections if I could, it'd allow me to keep the pressure rating on drawn copper instead ...
by userjjb
Sun May 20, 2007 7:33 pm
Forum: Pneumatic Cannons
Topic: Mach 1.6 Steam Cannon
Replies: 12
Views: 3688

Mach 1.6 Steam Cannon

http://www.spudfiles.com/uploader/uploadFiles/GGDT.jpg [/img] http://www.spudfiles.com/uploader/uploadFiles/SteamDiag.JPG Simplicity at it's finest! Traditionally burst discs are triggered by pressure, this steam cannon instead uses a temperature triggered burst disc. The burst disc also happens to...
by userjjb
Fri May 18, 2007 3:07 pm
Forum: Pneumatic Cannons
Topic: piston in a cross?
Replies: 9
Views: 2290

by userjjb
Mon May 07, 2007 11:38 pm
Forum: General How-To & Discussion
Topic: stuck nipple
Replies: 11
Views: 1921

Desolder the other half of the "nipple" and solder on an elbow right to the stuck male adaptor, then solder on a long length of pipe. Place the QEV securely in a vice and push on the end of the long length of pipe to loosen it. I'm assuming you screwed the adapter in there and that's it, so you shou...
by userjjb
Fri May 04, 2007 4:05 pm
Forum: Pneumatic Cannons
Topic: TIBS Launcher (New Piston)
Replies: 6
Views: 3288

Thanks everyone for the compliments :) the only thing i would change, would be to have a 1/4' check valve instead on the BV on the filling portion.. I suppose I could have put a check valve there, but I like having the ball valve to be able to control the fill speed. When I'm filling with a large co...