My hybrid plans

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
Potato Demon
Private 4
Private 4
Canada
Posts: 60
Joined: Tue Oct 16, 2018 4:22 pm
Been thanked: 1 time
Contact:

Sat Jan 12, 2019 7:24 pm

Hi, I’m thinking of building a handheld burst disk hybrid which operates with a 4x mix of propane and air. Here are the specs: schedule 40 steel pipe construction, 3” x 16” chamber, golf ball size x 40” barrel, spark plug and modified arc lighter ignition (or nichrome wire, a 9 volt, and a toggle switch). Can I fire this without a stand without falling over? Or do I need to make a stand for it? I’m considering a muzzle brake because it might actually help because of the amount of gasses from a hybrid (I think so anyway). I’m not a very large person (I’m 13) so the recoil might be a little much for me.
Last edited by Potato Demon on Thu Mar 28, 2019 12:05 pm, edited 1 time in total.
The world is the problem, the atomic bomb is the answer!
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25658
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 20 times
Been thanked: 8 times

Donating Members

Wed Jan 16, 2019 8:59 am

Plugging your specifications into HGDT gives us the following:

Image

1785 ft lbs (I assumed a 1 lb projectile) of muzzle energy is less than what you would expect for a typical 12 gauge shotgun load.

Here's a 13 year old kid shooting a much, much more powerful 10 gauge shotgun:

Image

If it's well supported and you lean into it properly, it shouldn't knock you over.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Potato Demon
Private 4
Private 4
Canada
Posts: 60
Joined: Tue Oct 16, 2018 4:22 pm
Been thanked: 1 time
Contact:

Wed Jan 16, 2019 1:04 pm

Ok, thanks. I guess it wouldn’t kick much more that the dumpster cannon (a bad idea!).
The world is the problem, the atomic bomb is the answer!
Potato Demon
Private 4
Private 4
Canada
Posts: 60
Joined: Tue Oct 16, 2018 4:22 pm
Been thanked: 1 time
Contact:

Fri Mar 15, 2019 8:54 pm

And if my metering pipe was made out of 1/2” schedule 40 steel, how long would it need to be?
The world is the problem, the atomic bomb is the answer!
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25658
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 20 times
Been thanked: 8 times

Donating Members

Sat Mar 16, 2019 5:13 am

hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Anatine Duo
Specialist
Specialist
Canada
Posts: 138
Joined: Sat Feb 01, 2014 11:16 am
Location: cottage country
Has thanked: 3 times
Been thanked: 2 times

Sat Mar 16, 2019 12:06 pm

regarding recoil, I use http://www.shooterscalculator.com/recoil-calculator.php

Muzzle energy is related to recoil energy BUT things like propellant mass and momentum are significant. I plugged in the numbers for the 7000 grain projectile at 339fps in a 10 lb launcher and the recoil was considerable with zero propellant.
Potato Demon
Private 4
Private 4
Canada
Posts: 60
Joined: Tue Oct 16, 2018 4:22 pm
Been thanked: 1 time
Contact:

Sat Mar 16, 2019 1:52 pm

Ok, thanks.
The world is the problem, the atomic bomb is the answer!
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 25658
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 20 times
Been thanked: 8 times

Donating Members

Sun Mar 17, 2019 6:16 am

Anatine Duo wrote:the recoil was considerable with zero propellant.
That's why recoilless guns work ;)

Image
hectmarr wrote:You have to make many weapons, because this field is long and short life
Post Reply