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Mega Hybrid

Posted: Sun Oct 15, 2006 8:29 pm
by flamintennisball
Hi all.
I'm new here as you can see, but that does not mean I'm new to spud gunning.

I am currently gathering parts for a huge hybrid and almost ready for constuction. Here are the parts I have:

2 foot long sch 80 8 inch steel pipe (chamber)
8 foot long steel pop can barrel :twisted: (seriously, pop cans fit perfectly)
8hp gas motor
1/2 inch thick steel plate
misc. pipe fittings



I plan to cut six to eight holes in the steel plate via blowtoch, so the plate can be bolted to the chamber. Pieces of angle iron will be welded to the side of the chamber for the nut to hold on. Thy reason why I don't just weld the plate to the chamber is there is no way I can get an airtight weld. with the plates as endcaps I will then proceed to the barrel. The barrel will be on a hinge for easy burst disk placement. It will have a bolt to secure it in place for firing. I will have a standard propane meter mounte on the side. With the basics done I will move on to the hard part, the motor. The motor will be for turning an old air compressor piston mounted right on the gun. I am hoping that i will be able to get up to 300 psi fuel- air mix with this setup. No more running to the air compressor for each shot.

I have one problem though, ignition
I cannot obtain a stungun where I live and want multiple sparks so a bbq ignitor won't work (i think)

Posted: Mon Oct 16, 2006 12:27 am
by CS
What is the blowing force on your blow torch?

Posted: Mon Oct 16, 2006 12:28 am
by iamthewalrus
who are u blowing is a better question?

Posted: Mon Oct 16, 2006 12:28 am
by BC Pneumatics
I belive you will need one with a blow force equil to 19psi (prostitutes per square inch)

Posted: Mon Oct 16, 2006 12:29 am
by CS
What is being 'blown' might be a even better question...

Posted: Mon Oct 16, 2006 12:30 am
by CS
BC- But then you will need 19 PSI [Pimps per Square Inch] to equalize the force exerted.

Posted: Mon Oct 16, 2006 12:32 am
by SquishY
Haha, If I remeber right from welding class they should all have the same pressure granted you are using the correct mixture and torch tip.If using OxyAcet and a cutting tip instead of dual use it will cut up to around 4' thick material but hell I did't pay attention to that part.

Posted: Mon Oct 16, 2006 12:34 am
by iamthewalrus
ur mom had the right mixture with my torch head last night :)

Posted: Mon Oct 16, 2006 12:34 am
by BC Pneumatics
I am slightly concerned that Mr. Ball cant make an air tight weld, and that Mr. SquisY is taking our posts seriously.

Posted: Mon Oct 16, 2006 12:36 am
by CS
5 PSI Acetylene
15 PSI Oxy
You cant up the ratio? Ya you ride the damn short bus.

Posted: Mon Oct 16, 2006 7:08 am
by Jolly Roger
Edit

Posted: Sat Mar 10, 2007 8:41 pm
by carter
car battery and a spark plug

Re: Mega Hybrid

Posted: Sat Mar 10, 2007 8:50 pm
by Hotwired
flamintennisball wrote:I am hoping that i will be able to get up to 300 psi fuel- air mix with this setup.
Jolly Roger wrote:uh dude do you mean you wish to take this up to a 20x mix?
What he said :shock:

A 300psi fuel-air mix, if it's not liquid is going to make a crater when you pull the trigger.

Posted: Sat Mar 10, 2007 8:56 pm
by willarddaniels
use an ignition coil instead of a stun gun.
You can't go up to 300 psi using propane. Propane liquifies at 125 psi, for higher mix ratios, see this thread 40X mix
EDIT: even sch 80 black iron may not be enough to withstand that rate of expansion and the resulting pressure spike.

Posted: Sat Mar 10, 2007 9:53 pm
by Insomniac
Yeah, a mix that high will DDT in a spectacular way. (meaning everyone in a 1km radius dies)