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time to man up & make a hybrid...

Posted: Fri Sep 19, 2008 3:08 pm
by FishBoy
well, just what the title says.

I would probably want to build someething very similar to this- [url>http://www.spudfiles.com/forums/the-lie ... 14345.html[/url]

It would most likely be 3-4x (5x?) mix maximum. I realize this requires no welding, soldering, etc. since all the parts are threaded, which i like. Anyway, I was wondering, what is the best (reasonably priced) ignition source, and what is the best thing to use as a propane reg.

Thanks, Fish

Posted: Fri Sep 19, 2008 3:15 pm
by Demon
Your link dont work.

Posted: Fri Sep 19, 2008 3:21 pm
by Davidvaini
http://www.spudfiles.com/forums/the-lie ... 14345.html


wierd its adding a space between the h and the t in html...

Posted: Fri Sep 19, 2008 6:27 pm
by FishBoy
any regulator tips/suggestions?
also any meter tips?

Posted: Fri Sep 19, 2008 7:33 pm
by DYI
1. Assuming you're staying at low mixes for now, a stungun or a flash cap. discharged through an ignition coil works well. If you want much higher mixes, a burning-wire type of system is more practical (although that's not to say that you shouldn't build a huge-ass, 500kV Marx generator instead :lol: )

2. You don't need a propane reg. The simplest solution is to take a torch, unscrew the curved brass pipe from the valve body, and then use a 1/4" compression adapter to connect it to NPT fittings.

3. Unless you want to build only one hybrid ever, consider using a manometric rather than a volumetric meter. I use one meter, with no adjustments, for everything from low-mix handheld hybrids, to a 3000fps airsoft gun, to the monster sitting in my shed right now that I haven't posted yet. All in all, manometric metering is the way to go for hybrids. I can guarantee that you won't regret the slightly higher startup cost it entails.

Posted: Fri Sep 19, 2008 9:50 pm
by frankrede
DYI wrote:1. Assuming you're staying at low mixes for now, a stungun or a flash cap. discharged through an ignition coil works well. If you want much higher mixes, a burning-wire type of system is more practical (although that's not to say that you shouldn't build a huge-ass, 500kV Marx generator instead :lol: )

2. You don't need a propane reg. The simplest solution is to take a torch, unscrew the curved brass pipe from the valve body, and then use a 1/4" compression adapter to connect it to NPT fittings.

3. Unless you want to build only one hybrid ever, consider using a manometric rather than a volumetric meter. I use one meter, with no adjustments, for everything from low-mix handheld hybrids, to a 3000fps airsoft gun, to the monster sitting in my shed right now that I haven't posted yet. All in all, manometric metering is the way to go for hybrids. I can guarantee that you won't regret the slightly higher startup cost it entails.
Whats manometric metering?

Posted: Fri Sep 19, 2008 10:49 pm
by DYI
Whats manometric metering?
Measuring the chamber pressure directly rather than using a fuel meter like most combustions and all but the most recent hybrids (so far, I believe that me, Spudfarm, and Larda are the only ones to build manometric meters for hybrids).

Posted: Fri Sep 19, 2008 10:53 pm
by frankrede
DYI wrote:
Whats manometric metering?
Measuring the chamber pressure directly rather than using a fuel meter like most combustions and all but the most recent hybrids (so far, I believe that me, Spudfarm, and Larda are the only ones to build manometric meters for hybrids).
Interesting, tell me more, how do you do it?

Posted: Fri Sep 19, 2008 11:57 pm
by mark.f

Posted: Sat Sep 20, 2008 6:46 am
by SpudFarm
since this is one of the topics i am PM'ing with fishboy about it is also one of the few i am watching if i can help on so i throw in a post.

it is simple, you have a 0-1bar pressure gauge and a air gauge. then you multiplies 0.045 by your mix number to find the amount of propane needed.

that would be for a 7x mix: 0.045*7=0.315 bar of propane and 6 bar of air.

just change the 7 in 0.045*7 to another mix number to find the pressure for another mix.

camera capacitor dumped into a ignition coil should work fine on 20x with a small gap (i would have used it up to 30x if i have made a cannon for it)

well, other members can take care of the questions raised from my post.

Posted: Sat Sep 27, 2008 8:32 pm
by noname
I used to use my hybrid at 6x and 7x with just a simple BBQ igniter. One wire from it is attached to the chamber wall (steel) and one is put through a schrader valve spark plug. The gap is less than 1/16" but works fine.

I'm setting it up again, and I've got a question for you guys. How bad is a thin layer of rust on the inside of the chamber? It's thin enough to flake off and see normal steel underneath, but I'd rather not take too many chances.