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Micro chamber help which one? .... and other questiones

Posted: Sun Jun 28, 2009 5:13 pm
by theBOOM
Ok guys, im building a micro 2x hybrid out of PVC ... don't kill me for using pvc, I think that 1/2 pipe rated to 600 psi+ should handle the pressure spike... Anway as a chamber I had first been thinking of using SCH 80 Pressure rated pipe, sadly I went to 3 hardware stores and none of them even carried SCH 80 Pipe. What I did find where SCH 80 Nipples.

Question 1:My question now is.... What would make a better chamber ? Sch 40 pressure rated pipe (600 psi) OR a SCH 80 Nipple ( to make it my chamber i would cut the 2 threads at both ends and just keep the middle piece of it (the pipe piece) that dosen't have a pressure rating.... (if you answer maybe you could give me reasons why not to use the other one?)

INFO:On my chamber I'm also planning on drilling out the stop in 2 PVC couplings (nsf-pw) and sliding and solvent welding them onto my chamber just to make it safer.

INFO:Btw my chamber is 1/2 inch and im using NSF pw fittings (only 2) the rest are brass fittings...

Question 2: Does anyone know where I can get a metallic stand like this one , im talking about the stand where the schrader is glued on and screwed .... I tried finding them at lowes but couldnt find them i just found a mini door hinge or something that looks similar but I'm not gonna use it.

Question 3: is ... what do you guys think would make an ideal ignition?? A MINI spark strip (2 sparks) or a single spark ignition .... Im using a mini piezo sparker from a lighter.. amazingly it produces almost the same spark as a 10 dollar piezo does :O. Its almost a 1/2 inch spark so im confident it can spark at a 2x or 3x mix, I know I shouldn't judge from the spark's size but I'm sure it will get the job done.

LAST question: What drill bit size do I need to make a whole for a schrader neck? I think I saw it in a guide but cant remember the link.

Thanks in advance :D

Boom :twisted:[/img]

Posted: Wed Jul 01, 2009 5:24 am
by theBOOM
BUMP ... some1 HeLP?

Posted: Wed Jul 01, 2009 5:32 am
by inonickname
No need to bump.

I responded back to your questions before, the "mount" that the schrader is on is a piece of 90 degree angle aluminum. The screw is to mount the sparkstrip on the inside of the chamber.

Your chamber will probably be ok..but if you can at least go brass. If you can get it working, I promise you that you will want moar.

You could get SCH40, sleeve it in couplers, then sleeve that in a larger size of pipe. That's what I did with my first minibrid (and it failed, but was unrelated to firing it).

Well it depends, seen as I chuck mine in a drill press and file all of the rubber off, then find a drillbit to match.

Posted: Wed Jul 01, 2009 5:39 am
by theBOOM
Thanks for responding.. i did find the mounts and the sleeving isnt going TOO well... :cry: I only got a coupler in and it was VERY messy... good think it turned out O.K ill give it a paintjob afterwards just to give it a glossy finish.... Instead ill probably coat the remaining chamber space (bout an inch and a half) with jb weld which is rated to 3.5k psi... then coat the jb weld on a thin layer of epoxy puty rated to 1.1k psi I think... and THEN put a piece of sch 80 1 inch pipe over the chamber... I think that would be safe up to a 3x or 4x mix tops...

And dont worry... this is only my "prototype" of what is yet to come... :twisted:

Thanks :D

Boom :twisted:

Posted: Wed Jul 01, 2009 5:47 am
by inonickname
I challenge you to a race to a 200X mini!

No joke, as soon as I have a pressure source up to it I'm doing it. I even have the stainless bar ready...

I'm unwilling to buy a scuba tank, so it might have to be a PCP pump when I get one.

Posted: Wed Jul 01, 2009 5:52 am
by theBOOM
Hm.. I still consider myself a "noob" .. this is my first hybrid...

But I guess I could instead of buying 1 inch rod of 2024 aluminum I could buy a 2 1/2 inch rod and maybe take it up some mixes higher :wink:

I dunno... I wouldn't like to challange the mini master.... for now :wink:
:[ dont kill me in my sleep!!

BOOM :evil:

Posted: Wed Jul 01, 2009 5:58 am
by inonickname
The kind of stainless I have available is extremely similar to the stuff used on the HyGac- just less machining friendly I'd say.

It will be a mini of the HyGac- which is extremely small considering that it was machined from a 60mm bar...

I'm interested to know what you're thinking of using for a burst disk coupler- they have always been the biggest problem for me. Other than that, it looks like you have it under wraps. If it leaks and it isn't at the disk, then just add more epoxy until it works. Good stuff :wink:

Posted: Wed Jul 01, 2009 6:40 am
by Technician1002
Good thing I'm not interested in building a mini. I have a block of high purity Zirconium. Check it's tensile strength compared to steel. :D

Posted: Wed Jul 01, 2009 8:01 am
by POLAND_SPUD
lol why do you want to use PVC?? I am sure you can get 1/2" or 3/4" iron pipes and fittings where you live.. so what's the point ?

Posted: Wed Jul 01, 2009 8:07 am
by theBOOM
Its only a prototype for now, and I wanted to make it out of pvc... whats so wrong about pvc if your taking safety precautiones chill out people im not gonna kill myself this chamber is rated to 800 psi and the pressure on the this gun arent gonna exceed 300 thts like using 120 psi in a 4 inch pipe diameter pipe...

Posted: Wed Jul 01, 2009 8:33 am
by POLAND_SPUD
it won't be much more expensive and at least you could be sure that its safe...

plus you could try higher mixes

Posted: Wed Jul 01, 2009 8:42 am
by theBOOM
Oh dont worry... im only taking this up to a 4x mix at the most.. I prboably wont... its made for 2x but im making a high mix hybrid out of an aluminum rod... well im not decided on what material yet but im making a high mix hybrid 20x+ soon :wink:

Boom :twisted: