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micro hybrid

Posted: Fri Oct 10, 2008 2:13 pm
by jean
hi

i can´t find a really micro hybrid on this site.
what do you think about a micro hybrid with chamber volume 1ccm?
use syringe to fill up to 10x-20x?

jean

Posted: Fri Oct 10, 2008 2:21 pm
by i-will
sounds good to me. u can be the first to post one on this forum. go for it.

Posted: Fri Oct 10, 2008 2:46 pm
by jonnyboy
Sounds good to me. I doubt many people consider becuase for a little more money you can have a bigger one. Why would you go to the hassle to pre charge with air and whatever for firing a tiny bb. Doesn't make much sense. Where are you going to find pipe in micro size that can hold a 20x mix. Where are you gonna find a 1/4 or lower union. :shock: But if it is what you want go for it. :)

Posted: Fri Oct 10, 2008 2:51 pm
by jackssmirkingrevenge
jonnyboy wrote:Why would you go to the hassle to pre charge with air and whatever for firing a tiny bb. Doesn't make much sense.
If you could push that tiny BB past the speed of sound, that would be worthwhile in my book ;)

Posted: Fri Oct 10, 2008 4:02 pm
by FishBoy
I have always had a mini hybrid in the back of my mind, you should try it. Also, i would suggest talking to DYI about manometric metering, it would help. if you actually did it it would be sweet.

Posted: Fri Oct 10, 2008 4:10 pm
by THUNDERLORD
In my post Here , I was wondering about a component for fueling one.
Just after posting that, I started doing metal work in a factory welding shop (a lot of hours/week!) So I haven't been back online until today.
Interesting thing, in the shop almost everything is steel tubing, So I've really been interested in a micro or mini- hybrid.
I've been wondering if the pressure from a cartridge mentioned in that post could be sufficient to "diesel" a small chamber mixture(?)

It sure seems more practical to build a very small scale hybrid, especially if it will rapid fire. :roll: 8)

Posted: Fri Oct 10, 2008 4:48 pm
by jonnyboy
jackssmirkingrevenge wrote:
jonnyboy wrote:Why would you go to the hassle to pre charge with air and whatever for firing a tiny bb. Doesn't make much sense.
If you could push that tiny BB past the speed of sound, that would be worthwhile in my book ;)
That would be cool but what after that? Your not going to get much damage from an airsoft bb or a real one. I think its more for demonstration purposes. To repeat my question again where would you find a union small enough?

Posted: Fri Oct 10, 2008 4:48 pm
by mark.f
Well, there is a simple and slightly more reliable way to fuel mini hybrid than the conventional ways:

Simply fill with approximately the right amount of propane. i.e. for a 4x mix, inject approximately 16% of the chamber volume of propane (again, doesn't have to be exact).

Fire up your continuous spark inside the chamber. I'd suggest some sort of 555-chip driven ignition coil. The spark should have a fairly high frequency.

Inject air slowly through a needle valve. The air should agitate the fuel mixture enough to promote a good ignition when oxygen levels become high enough, and when they do become high enough, the cannon will fire.


That would be the route I would go.

Posted: Fri Oct 10, 2008 5:11 pm
by Hotwired
If fuelling one mini hybrid sounds like too much work then obviously a Brocock cartridge system isn't for you. It uses a small valved cartridge to hold a tiny charge of 3000psi air and one pellet then after firing needs to be reloaded with air and another pellet. The plus side of that is being able to use the cartridges like firearm cartridges.

But really I'm not seeing a problem in a minature hybrid, dam sight less of a problem to make than a large hybrid and could cope with extreme mixes very much more easily and cheaply.

Could be right fun and games getting the mixture right in a small chamber involving high pressures but I could see marks idea working. I just wouldn't like to have to feed the chamber til it fired.

Posted: Fri Oct 10, 2008 5:18 pm
by Fnord
If you're going to be using 20x mixes constantly, you won't even need a meter. Just flood the chamber with propane at atmospheric pressure and add 310 psi of air. Instant 20x mix.

(Note: this may be off slightly. I did the math a long time ago, but I think the mix may be slightly rich. Probably won't make much difference though)

Also, I'd tend to go slightly bigger than 1 cc. a short length of 3/4" steel would be fine.

Here are two good mini hybrids:
http://www.spudfiles.com/forums/cptn-la ... 12235.html

http://www.spudfiles.com/forums/the-bra ... 11795.html

Cptn law is around every once in a while, but I think Nova got banned for arguing, so he can't really give you any advice or details on his gun.

Posted: Fri Oct 10, 2008 6:19 pm
by DYI
If you could push that tiny BB past the speed of sound, that would be worthwhile in my book
My 30x mini-hybrid can fire that tiny BB at 3000 fps on its better shots. Such a goal isn't exactly a huge stretch for most of us.

There's a very simple way to fuel a mini/micro hybrid: simply build the chamber, and hook up your existing universal fuel meter to it. :P

Posted: Fri Oct 10, 2008 7:56 pm
by CasinoVanart
_Fnord wrote: Nova got banned for arguing, so he can't really give you any advice or details on his gun.
mmm, my bet is that he is still lurking, i also bet that he would love to see a tiny little Hybrid, 1ccm is a bit small i think though, from memory the Brass Bruiser was 107ccm, something a hundred times smaller than that would be a real challenge to get firing reliably... Not to say it can't be done though. 8)

thx

Posted: Sat Oct 11, 2008 3:36 pm
by jean
hi

thx for answer
i see you are positiv abaut nicro hybrid :)




in my head are many questions....

i will pump in the fuel/air mix in the chamber with a
syringe/homemade-pump and i don´t know
how much heat will enter my mix by compression
(up to 20 bar in one pumpstroke!). self inigtion like a diesel carmotor?!
scary or not?

what do you think about electrostatics? many friction come when stroke the pump!
scary or not?

inigtion....16kv bbq inigtor....?

hgdt say 200bar maximal chamberpressure by combustion a 25x mix. what is with ddt in a 1-5ccm chamber and how high can the pressure go?


a picture... first prototype cartridge

Posted: Sat Oct 11, 2008 3:47 pm
by ALIHISGREAT
i would have the mentality that bigger is better and make a bigger one for not much more money... maybe a marble shooter? although a mini-hybrid is a project worth pursuing as it won't be too expensive to get the materials for high mixes.

material

Posted: Sat Oct 11, 2008 4:31 pm
by jean
hi

first a link http://www.kupfer-institut.de/front_fra ... ai2006.pdf
site 15/16 show the workingpressure of copper tubes
site 16 show a picture of bursting 22mm copper tube at 280 bar

mh bigger is better yeah i know but its time for hybrid plinker;) hope for help.
in the end my dream is an small hybrid plinker, fast ready to shoot (piston valve like _fnord?), and power like 10-15 ftlbs.

in my basement i had 1/8 brass t
i don´t know the dimension but next morning i will show and and post a photo

jean