Hybrid Mix

Woody · Wed May 13, 2009 4:22 pm

First of all I have a good idea of what 2x mix, 3x mix, etc means, but could someone tell me exactly what it is. Also, I know you should make hybrids out of steel or a similar strong metal, but what would be the highest safe mix to fire in a pvc hybrid of say a 4" chamber (propane for fuel) before the possibility of the chamber failing?

spudtyrrant · Wed May 13, 2009 4:38 pm

the ambient air pressure is about 14.7psi and combustion takes place at a certain mixture in the air so when you add twice the air you can add twice the fuel:1x=one shot of fuel no air pressure 2x=2 shots of fuel 14.7 psi pressure ect.
if you are using sch.40 i wouldn't suggest any higher that a 1.5x mix
if you are using sch.80 2x maybe 3x-4x if you have remote ignition

c11man · Wed May 13, 2009 4:48 pm

the highest safe mix for any sch PVC is 1X. at even 1.5X pvc can not take the large pressure spikes and will form smal cracks that you can not see and eventualy fail. it could fail after 3 or 30 shots but it WILL fail. these cracks will form even if the pressure spike is under the pressure rating of the PVC pipe because PVC is not good at taking pressure instantly but the pressure gain is at a slow enough speed in a 1X mix that it is safe for repeated use.

Woody · Wed May 13, 2009 5:23 pm

Okay, thanks for the information.

c11man · Wed May 13, 2009 5:32 pm

so get a iron or copper chamber and burstdisk holder. the barrel can be pvc but metal is always better. aslo download hgdt because i dont think you fully understand the power of a hybrid cannon. a 4inch would be extremly powerful. hgdt may seem complicated but its not

Woody · Wed May 13, 2009 6:17 pm

ok, well yeah I know as you bump up the mix it can really get powerful. I looked at a chart once that measured power with difference mixes in this one gun and it increased so much as the mix gets higher.

Well, say I used a 2" chamber out of galvanized steel or iron. I don't want to kill myself or anything, so in that case what would be the highest safe mix to use.

One other thing, is it okay for the pieces used to be threaded?

c11man · Wed May 13, 2009 6:48 pm

instead of me telling you all this why dont you look in the hybrid section at cannons like the ICON hybrid by Trigun

spudtyrrant · Wed May 13, 2009 6:59 pm

c11man wrote:the highest safe mix for any sch PVC is 1X. at even 1.5X pvc can not take the large pressure spikes and will form small cracks that you can not see and eventualy fail.

i am sorry but i have used a propane 1.5x hybrid for over 150 shots with no fail you are wrong in that assumption

c11man · Wed May 13, 2009 7:11 pm

what size chamber is it? the chamber size would play a huge role in its strengh.

am sorry but i have used a propane 1.5x hybrid for over 150 shots with no fail you are wrong in that assumption

thats the thing. you NEVER know when it will fail. its not like there is a set amount of shots before it fails. your cannon could last a lifetime of shooting but the next guy who makes a pvc hybrid might have it fail after just 5 shots. witch is the scary part because it could work fine one shot and expolde the nex

Moonbogg · Wed May 13, 2009 9:07 pm

c11man is just pointing out that low mix PVC hybrids have a noted failure rate, even though it may not be very well known. After all, not many people make hybrids in the first place, so any failure here and there is plenty to take note of. Plastic shards at 2 or 3x would appropriately suck in quite a splendid manner as they discover your skin during their trip through the atmosphere.
Oh, threaded fittings are great for hybrids. Consider aluminum pipe as well. Its plenty strong and much lighter than other metals. Keep in mind though that any holes in the chamber and even in the couplings will really weaken its strength. A single hole can reduce strength by about %50 or more.

c11man · Wed May 13, 2009 9:12 pm

thanks for the support Moonbogg.

again just brouse the showcase for other hybrids. if you want a seriosly powerful hybrid build one like Moonbogg's but make it out of thicker aluminum so that you can take it to 10x

spudtyrrant · Wed May 13, 2009 10:25 pm

i believe you guys know what you talking about but i have never heard of a "correctly" built full sch.40 gun failing at a 1.5x mix. a 1.5x mix will produce about 100-110psi if done correctly using propane as fuel. i have seen plenty of 4 inch piston cannons taking higher that that for prolonged periods of time. and if shock pressures were so much more dangerous than prolonged air pressures people wouldn't be so willing to let adv. propane dwv guns slip by with just "be careful next time"

Moonbogg · Wed May 13, 2009 11:43 pm

spudtyrrant wrote:i believe you guys know what you talking about but i have never heard of a "correctly" built full sch.40 gun failing at a 1.5x mix. a 1.5x mix will produce about 100-110psi if done correctly using propane as fuel. i have seen plenty of 4 inch piston cannons taking higher that that for prolonged periods of time. and if shock pressures were so much more dangerous than prolonged air pressures people wouldn't be so willing to let adv. propane dwv guns slip by with just "be careful next time"

I think people let those slip by because ABS is tough and gummy. It doesn't shrapnel like PVC.

spudtyrrant · Thu May 14, 2009 1:19 am

http://www.spudfiles.com/forums/viewtopic.php?t=5889&
i was speaking of pvc' of course i do think abs is much safer i agree with you their i just don't think a 1.5x spudgun is a dangerous as everyone thinks they are

Moonbogg · Thu May 14, 2009 9:11 am

c11man wrote:thanks for the support Moonbogg.

again just brouse the showcase for other hybrids. if you want a seriosly powerful hybrid build one like Moonbogg's but make it out of thicker aluminum so that you can take it to 10x

Oh I could just imagine the recoil...might as well choose a prosthetic arm now!

But yeah, do it.