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Posted: Fri Jun 23, 2006 11:14 pm
by NeoSpud
there a hand held mini hybrid on this forum with sch 40 dwv fittings on it that can handle 2x mixes.
obviously that guy doesn't have weak-pipe-a-phobia like most people on this site
Yep, thats my MiniHybrid.
Don't forget that the original hybrid built by DR was ALL SCH 40!!
There's no need to be hybrid-freaked, but don't be too nonchalant either.
Posted: Fri Jun 23, 2006 11:25 pm
by huse_spud
you built a hybrid like mr. plow's? cool! you're fearless. i like that!
wait... i can't find it on spudfiles, if u really made it please post something.
Posted: Sat Jun 24, 2006 12:42 pm
by WOW!!
NeoSpud wrote:WOW- what the fork would a coupling every 10" do? Are you just talking out of your ass or what?
Anyways, nothing on a hybrid is safe. Nothing. If you have pipe rated to 200psi, then a 2x or maybe 3x can be repeatedly done without failure, but this does NOT make it safe by any standards. It took a 4x mix to blow the DWV cleanout on my MiniHybrid, but that is no scientific determination of a DWV cleanout strength, much less pipe strength.
On an unrelated note: "responaple" just got added to my list of favorite idiotic spellings.
What it does is gives a extra layer of plastic for more strenght. My friend's Hybrid is made out of Sch40 2" and we take up to a 4X mix and it is fine, by putting a coupling every 8" i think it was and pipe clamps on it to it is fine, we do fire it behine a block wall that I made, It works well. And no I dont think Iam talking out if my ass but I might be.
Posted: Sat Jun 24, 2006 6:33 pm
by boilingleadbath
2" sch 40 has a pressure rating of 280 psi.
That's above the average peak pressure generated by a 4X mix, and those ratings have generous saftey margains.
Your couplers arn't doing anything. Remember, just because you did x and y didn't happen, doesn't mean that x prevented y from happening.
Anyway, yeah, an extra layer of plastic.
But if only a small portion of the chamber is wrapped like that, who cares?
Posted: Sat Jun 24, 2006 7:19 pm
by cannon freak
If you were making a mini hybrid you could put couplings up the whole length, that would help would it not?
Posted: Sat Jun 24, 2006 9:42 pm
by carlbelcher
I think that’s probably a bad idea. I think that if anything on a cannon is going to fail, the glue joints will probably go first.
Posted: Sat Jun 24, 2006 9:48 pm
by ProfessorAmadeus
i think thats what he iis trying to say. I dont know about you but i would rather have a joint fail than be exploded into lots of little pieces.
Posted: Sat Jun 24, 2006 9:49 pm
by huse_spud
so lets review hybrids are you not supposed to go over a 4x mix with a plastic hybrid?
and a let's say 2x mix for example, if i use 37 psi (propane) for a regular shot i should use 74 psi for a 2x? and then add 14.7 psi of air pressure?
just how much energy in psi is created in a 2x mix?
Posted: Sun Jun 25, 2006 9:30 am
by WOW!!
It all depends on te chamber size, you need a metering pipe, that mesures out the propane and injects it in the chamber.
Posted: Sun Jun 25, 2006 11:49 am
by beebs111
yeah, you want 4.04% propane/ air ratio, so lets say you had a 2" chamber that it 18" long, you need,a .5" pipe that is just a hair under 3" long to meter out a 1x mix. for a 2x mix, you meter the propane out 2 times, and add 14.7 psi, 3x mix you meter it out 3 times, add 29.4 psi. so on and so forth
Posted: Sun Jun 25, 2006 1:03 pm
by cannon freak
No I don't mean taking couplings and attaching them to the pipes and then to another coupling, I mean what if you took a hybrid and then took a coupling that fit, grinded out the little lip inside and then solvent weld them onto the outside of the pipe the whole way down. This would increase the streangth wouldn't it.
Posted: Sun Jun 25, 2006 7:26 pm
by dan116
thats a good idea, but its defeating the whole purpose of me tryin to make a clear hybrid, it will just cover it too much.
Posted: Mon Jun 26, 2006 2:41 pm
by dan116
also i've charged my air cannon to 125psi and its made out of ABS, which is not even pressure rated. To this date I have had no problems with it.
Posted: Mon Jun 26, 2006 10:47 pm
by carlbelcher
ABS to 125psi thats asking for trouble.
Posted: Mon Jun 26, 2006 10:59 pm
by frogy
Dan don't talk about ABS pneumatics, someone who doesn't know what their doing, well, someone like you, will see it and make one out of ABS and hurt theirself...
Really, ABS combustions are ok for Aerosol (I don't really trust mine with propane)
But don't use it for pneumatics... Cellular Core isn't good for that, it wears over time...