strafer idea

[laz91]

i'm thinking about building a strafer bb gun but instead of using a air compresser could i just make a tank that is full of compressed air that is being filled by one of those little 20$ compressers that don't have a tank i can get the pressure to 180psi with the compresser even though it says 300 psi it only goes to 180 . but could i just connect the gun to a tank instead of a compresser. has anyone tried this.

[laz91]

or possibly if you could make a adapter to adapt it to hook up to a pressure washer instead.?

[saladtossser]

i was just thinking bout a reg and pressure washer

and the gun... its been done, by somebody. still great idea.

[laz91]

the only thing im wondering is how much psi would a powerwasher realy will be delivering since there like 3000 psi powerwashers but then like how much force are they really gonna be giving . it would probably be more then enough?

[spudshot]

if you're planning on using PVC FORGET IT even 180 in PVC is very dangerous, use something else like steel, aluminum, or brass.

[laz91]

y forget pvc i dont think that the pressure will be that constant since it will have a place to come out and if it's realy 3000 psi metal won't do much better?

[drac]

HAH! HAHAHA! HAHAHAHAH!!!!!!
Metal is capable of holding 10 times as much PSI as PVC if you construct your chamber well. And the pressure will be constant untill you fire, so even if you let out 100 PSI, youll still have 2900 untill the next shot.

[boilingleadbath]

Pressure washers deliver pressurized water.
This pressurized water is typicaly delivered at volumes like 3-5 gallons/min.
That's more than 1/2 of a cubic foot... normal air compressors deliver 30-50 cubic feet/min... totaly useless for our application.

I don't know where you got the idea that 180 psi is a dangerous pressure. It's only about 1/2 the pressure rating of 1.5" sch 40 pvc - quite safe, even for a theaded fitting, considering that they have generous saftey margines on those ratings. If you still don't feel safe, use sch 80 - the rating is significantly higher.

As to metal being rated 10 times higher, that's bull. A quick estimate tells me that steel should only be rated 5 times higher (30,000/6,000).
Searching indicates that carbon steel pipe in sch 40 1.5" is rated to 2100 psi - searching also indicates that 1.5" sch 40 pvc is rated to 330 psi.... Steel is rated 6.3 times higher.

Significantly delayed edit: And as to a gun with the air storage tank built into it, Full metal jacket has built such a contraption. (he's a member of spudtech)

[drac]

Oops. Guess i should research before pulling figures out of my ass.

[laz91]

but if a power washer is so much more powerful y not we all use them as compressers? but i don't think a powerwasher will realy compress but then why do they say 3000 psi? and you can use a pressure washer without water?

[boilingleadbath]

Pressure washers are capable of producing more pressure than your typical air pump, but not many here make cannons capable of holding 3,000 psi. (acctually, I don't think anyone has yet, but someone was going to make a 2,000 - 3,000 PSI burst disk cannon) Also, the rate of flow is terrible - it'd take forever for you to fill even a small tank. Thirdly, a pump for water probably wouldn't compress air well, if at all - it's just not made for it.