SpudFiles

You obviously cant get any sch 80 stuff at home depot and your those types of store. Just go in the yellow pages and go to "sprinkler" in there you should find some stores that sell pipe to contractors; those types of stores are more likely to have it. If it is sch 80 its pressure rated and Im almost sure that the walls of the pipe are strong enough for a hybrid but I dont know once you glue all the pipe together if it will blow apart. Because PVC glue and primer makes a strong bond between the pipes you are glueing because it will fuse them together, but I dont know if that is true with conduit thus making the joint in your gun weak not the actual pipe. The reason I say that is because conduit is made for carrying electrical stuff so when they say sch 80 I dont know wether that means it can hold a lot of pressure or that it can withstand strong forces in the ground. Now that I think about it I think I recall someone making a combustion out of conduit pipe BLB would proably know if conduit should be used on a hybrid.

Sch 80 is a wall thickness, that's all. Heck, you could have cell-core sch 80, though I'v never heard of it.

I would suspect that so long as the conduit is acctually PVC instead of something else, the solvent welding will work out... and check to make shure it's not cell core, or it won't be the joints that'll be failing! Personaly, I wouldn't cut this corner (it's not rated for pressure, but it <i>might</i> be built in the same way as the stuff that is), but they are your body parts. (Read: remote ignition)

One might wonder where you'll be getting the pressure rated fittings, considering that you can't find real sch 80 PVC pipe, but I'm suspecting that you'v either found a weird store (for instance, I have a local store that stocks some sch 80 fittings, and sadles, but neigh a pressure rated pipe. It's almost erie.) or you'll be ordering online.

conduit seems to be more brittle than normal PVC, it is thick, and seems durable, but i wouldnt trust it as it wasnt made for pressure and wasnt tested for the standards that pressure pipe needs to meet

ok thanks guys that helps alot, but im not plannin to buils a hybrid soon(maybe another year of smaller stuff) but thanks for the help

Aaron ????? wrote: the only problem is that i want to know how much pressure its making but i cant find any check valves

dont waste money on a cheak valve I know a better way, just go to kragen and buy a cylinder presure tester it6 is a big guage the goes to 300 psi and has a built in check valve for $10.

spudshot wrote:you'll probably not have a hybrid left after your first 4x shot, i believe your class 18 pipe is rated to something like 300 psi? well a hybrid creating 270 (lets just say that, since L13 recorded it) would be dangerously close to the breaking pressure, but also the repeated pressure spikes will start to weaken the pipe, and it will fail eventually
aaron, look around industrial tool stores, they sometimes have check valves that are used on air compressors

the pressure rating on pipes isnt the busrt pressure, thats just what its rated for. Dont forget that pressure rated pipe is rated for water pressure, not air pressure which is different.

Are the burst disks what holds the pressurized mix of fuel/air? seems to be thats all ive noticed holding back all that pressurized mix. I would like to try this out, it doesnt seem as complicated as it looks to me. Dump a metered volume of propane at a certain PSI and juice it with air?

Spudshot-SS wrote: Are the burst disks what holds the pressurized mix of fuel/air? seems to be thats all ive noticed holding back all that pressurized mix. I would like to try this out, it doesnt seem as complicated as it looks to me. Dump a metered volume of propane at a certain PSI and juice it with air?

Ok, build me a hybrid and then we'll see how complicated you think they are.

im not saying its not a complicated spud gun, but what im saying is that i thought hybrids had some sort of valve that was timed by point of combustion (custom circut board with the valve programming and ignition built into one board maybe?) it was just a burst disk it would be as simple as calculating the correct metered amounts of compressed air and propane (or mapp gas heeheheh)

since ive been looking them up it seems that a union and a burst disk is the best way to go seeing that the burst disk releases its charge faster than any timed valve.

SpudShot-SS wrote:im not saying its not a complicated spud gun, but what im saying is that i thought hybrids had some sort of valve that was timed by point of combustion (custom circut board with the valve programming and ignition built into one board maybe?) it was just a burst disk it would be as simple as calculating the correct metered amounts of compressed air and propane (or mapp gas heeheheh)

since ive been looking them up it seems that a union and a burst disk is the best way to go seeing that the burst disk releases its charge faster than any timed valve.

Oh, oops. Sorry about the misunderstanding. Nope, no fancy timing, although DR did make one with a self actuated sprinikler valve using a safety pop-off valve. You're entirely right about the metering thing. Add a couple shots of propane and add an equivalent number of atmospheres to compensate.

Just a small aside, how long have you been in this hobby? YOu sound like you've been spudding for a while.

well im 22 right now but ive been spudding since i was in my early teens

how small of a mini? like a marlbe sniper or somthing

if that was directed towrds me then yeah a small 2" chamber to shoot frozen and normal paintballs

yah it would be fine fore a while at that pressure but after a while fatigue would set in then boom and then ouch then hospital

i dunno man, pvc seems to take the abuse pretty good, ive gotten over 1000 shots off my propane cannon and the only sign of wear/burning is at the threads on the cleanout. i mean, 1000 shots through plastic should at least make the pvc a little yellow but it hasnt, i work a full time job making these fittings and when the temp gets too high pvc gets yellowish, then brownish black when its burnt, and that takes at least 400 degrees for more than a minute straight

Mechanical fatique is an entirely different phenomenom than heat damage.