Distance

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
Simple_Man66
Private
Private
Posts: 4
Joined: Sat Oct 24, 2009 7:45 am

Sat Oct 24, 2009 10:46 am

Hi All

Just joined. Been reading for a while now.
I was wondering aprox distance I should get with my cannon?
metered propane,3in X 24in chamber with a 1.5in X 4ft barrel.
I have been trying different psi in my meter. My best distance so far
is 50 yds
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26203
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 569 times
Been thanked: 345 times

Donating Members

Sat Oct 24, 2009 10:59 am

Welcome to the forum, it would help if you could furnish projectile and launch angle details, 50 yards is a little low for a cannon that size. Do you have a fan or similar mixing device?
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
Technician1002
Captain
Captain
Posts: 5189
Joined: Sat Apr 04, 2009 11:10 am

Sat Oct 24, 2009 11:45 am

When the mix is a little rich, this lower power is often seen. Too lean most often results in failure to fire. Vent the chamber fully between attempts. Start at lower pressure on your meter and work up until it fires. That first fire will be close to the right mix. Spuds should go at least 100 yards with the proper mix.
Simple_Man66
Private
Private
Posts: 4
Joined: Sat Oct 24, 2009 7:45 am

Sat Oct 24, 2009 12:09 pm

Sorry bout that I am just launching spuds,and yes I have a fan
Simple_Man66
Private
Private
Posts: 4
Joined: Sat Oct 24, 2009 7:45 am

Sat Oct 24, 2009 12:16 pm

lowest pressure that would fire gave me 25 yds. pound by pound increase til i got 50 yds. Then dramatic fall in distance. checked for leeks
in the chamber and in the meter,none.

Thanks
User avatar
Technician1002
Captain
Captain
Posts: 5189
Joined: Sat Apr 04, 2009 11:10 am

Sat Oct 24, 2009 12:34 pm

http://www.spudgun.info/Spud-Gun.htm

I'm not sure what the problem is then. Typical distance claims are about 100 meters. It is very important to fully vent out the burnt gas from the prior shot between each shot. Lack of oxygen due to being in a hurry will result in low distance. That should be able to shoot the length of an American football field.
Simple_Man66
Private
Private
Posts: 4
Joined: Sat Oct 24, 2009 7:45 am

Sat Oct 24, 2009 1:22 pm

Thanks for the input Guys.

I changed my spark source and WOW!!!!!!!
Guess I had a weak sparker?????

Thanks again
Post Reply