SpudFiles

Well, I made a propane meter for my cannon. I am having a problem with get enough.......how to say it....uumph out of it. It really doesn't crack like it did with hairspray or shoot as far. I think it might be that the chamber size is too small, a .87:1 chamber to barrel ratio. It really cracks with a light projectile but heavier ones it kinda just blows it out. Any thoughts on what the problem could be? I have messed with propane % and that helps a little.

have you tried altering the ratios a little, higher or lower? your calculations might be a little off, and if the mix isn't right then performance will suffer. Note that noise is not always equal to the best ballistic performance

Have you tried the chart on advanced spud. com. It's exactly what you need. Google it and it should come up.

Yes I have adjust propane % up and down and have figured out what works best. I just am not getting the power out of it. I used to be able shoot potatoes, walnuts, and ear corn so far you could barely see it, now it just kinda lobs it not really up to it's previous ballistic performance. I have an air ram built into it, making for a recoiled gun like a field gun so I think it is robbing too much of the expanding gasses so I think I have to either shorten the air ram or make the chamber bigger. My thought was that there is not enough expanding gases supply both. Maybe the propane is not getting mixed good enough? Maybe I should add a chamber fan?

A chamber fan is necessary when using propane. It helps mix the gases and get air into the tank when you open the back of the gun. And what type of ignition are you using.

I am using an electronic grill ignitor with 2 points of ignition

Recoiled_monsteR wrote:I am using an electronic grill ignitor with 2 points of ignition

for 10-20 bucks get a stungun! =)

Some pictures of your setup will help us help you

for 10-20 bucks get a stungun! =)[/quote]

Stun guns aren't legal in alot of places.

still the ignitor was half the cost of a stun guns that i can find. I'll try to get some pictures up, they are on a micro SD card in my phone and I think I misplaced my converter to SD. I'll see if I can find it

Recoiled_monsteR wrote:still the ignitor was half the cost of a stun guns that i can find. I'll try to get some pictures up, they are on a micro SD card in my phone and I think I misplaced my converter to SD. I'll see if I can find it

i got two stuns, one was 10 other was 20

Lucky......the ones I can find go for $30 on the cheap end, but I always keep my eyes peeled for a good deal at gun shows and other festivities

Recoiled_monsteR wrote:Lucky......the ones I can find go for $30 on the cheap end, but I always keep my eyes peeled for a good deal at gun shows and other festivities

do you want where i got mine from?

for my big bertha cannon i needed something very powerful,my chamber alone is 4 feet

But, the electronic ignitor works great and I got a discount 'cuz I work at the hardware store I bought it from

Sure, where did ya get your stun guns? Always figured it'd be nice to have a stun gun ignitor. Prolly will need it in the future, I want to make a 3" barrel field gun essentially. Still workin out the kinks and designing it. Eventually I am gonna build a 1/2 scale soviet SU-152 and this is how come i am working on a recoiling, propane powered cannon. Figured I'd test it out on a small scale before I went and made a behemoth of a potato field gun.