rebuild after the explosion

[brplatz]

this is the rebuild of the double tank air cannon. works very nice and only spend $30 bucks on it .

oh and D-cell battery and some duct tape work amazing as projectiles, especially when shot at full soda cans.

here some pics

[hi]

hate to spoil the fun, but you have what looks like a dwv reducer. it might be pressure rated, so check and see what it says, but its probably dwv.

its a simple fix if it is, just saw it off and use a coupler and a bushing.

other than that it looks great.

ps- what kind of plane is that in the back ground? it looks like some sort of 3d airplane. i had a e-flite tribute that looked just like that.

[bigbob12345]

nice job and it is very clean but two things
you used DWV fittings(bell reducer) and they should be replaced immediatly or it may explode again(this is the reason it exploded before)

And the sprinkler is constricting flow quite a bit for a chamber that size.
Wht i would do is cut off the bell reducer from the chamber and take the sprinkler and barrel off it for other uses. then make a piston valve(3in tee 2in porting should work good)

but if I ignore the DWV nice gun

Edit:hi beat me to the DWV thing

[brplatz]

@hi,
that 3d airplane in the backround you see is my Airfoilz Yak 54.
it flew nice until i crashed it :-/.
http://www.airfoilz.com/
ok so the DWV fitting is the part on the tank going from 4" to 2" right?
ill go check it out.

thanks

[Counterstriker]

I don't see the blowgun?

[bigbob12345]

Oh yeah one more question
Hows power?
I would expect a lot off a chamber that large but then there is that sprinkler valve...
and about the DWV it is hard to find pressure rated fittings above 2in in most places so you may have to order online.
And im glad to see someone that is willing to switch out the DWV fittings, most people just have a fit when we mention it

counterstriker: the sprinkler is not modded which is fine

[brplatz]

yah so i just looked and it is DWV. Bummer. Im leaving to go to juarez tomorow so wont be able to change anything soon. is the DWV really that bad?

also i got the sprinkler mod working now

[bigbob12345]

is the DWV really that bad?

no, if you dont mind high speed pvc shrapnel
yes, if you do mind high speed pvc shrapnel

there have been numerous explosions due to the use of non pressure rated parts(DWV)

[hi]

well other than the fact that it can and probably will blow up, its just fine.

[brplatz]

ok ok i get it. i didnt really want to have to waste those 2 inches off the tank but oh well. safety first right?

[hi]

you could cut off 6 inches and the power would be about the same...

[watto]

Is the chamber pipe pressure rated?

[brplatz]

it should be sch-40 if i am correct. i will have to change out the adapter when i get back. thanks for the help

i am still trying to figure out how it all works with size of chamber and psi and valves and all the goods. and funds are running a little low ATM. so maybe time to get a job.

[Counterstriker]

safety first

Number 1 rule of making spud guns.

[SpudUke5]

t should be sch-40 if i am correct.

SCH 40 is not a pressure rating. That is wall thickness. SCH 80 is another wall thickness rating that is common, but not as common as SCH 40.

NSF-PW is a pressure rating, PW meaning "potable water". NSF-61 is a pressure rating as well that is usually given to mcmaster carr pipe. Also if it has a pressure rating on it, example: 330 psi means is pressure rated. And ASTM 2466 means that the pipe or fitting is pressure rated.

So take your pick