New to spud cannons and I have a question.

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Bigredpotato
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Fri Jan 26, 2018 10:58 pm

So I just got my first spud cannon and it fires like a charm,but I was wanting to use different ammo besides potatoes. So I went to Walmart today and got some foam practice golf balls. The thing is they are slightly bigger than my barrel ( about .1 of an inch bigger). They fit if I squish them a bit but they are a little tight. My question is how tight is too tight? I mean I can push it down the barrel without too much trouble but I feel like it might be too tight. I don't want my cannon to blow up on me.
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jrrdw
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Sat Jan 27, 2018 7:04 am

If it's soft ammo you should be fine. There are ways to test what ever you want to launch. Is your cannon a pneumatic or combustion?

Welcome to Spudfiles. :mrgreen:
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farcticox1
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Sat Jan 27, 2018 7:57 am

any pictures ?

Interesting, I might try some 22mm Nerf balls in a 3/4" PVC barrel, which is about 21mm ID :idea:

Also looking on Ebay there are different sizes of foam golf balls, 41mm upto 42+. The 41s would be a nice fit in 1 1/2" pvc :idea:
Bigredpotato
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Sat Jan 27, 2018 2:23 pm

jrrdw wrote:If it's soft ammo you should be fine. There are ways to test what ever you want to launch. Is your cannon a pneumatic or combustion?

Welcome to Spudfiles. :mrgreen:

Combustion. They are soft but I doubt they'd break apart under pressure or anything like that. They need to be slightly compresses to fit. When I pack them in they have a quite noticeable resistance compared a potato. The barrel I have has an inside diameter of 1.5 inches where foam golf balls seem to have a diameter of about 1.6 when uncompressed. Also the fuel I use is hairspray.
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Ragnarok
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Sun Jan 28, 2018 12:20 am

Unless you're actually having to seriously force a projectile down the barrel, the frictional forces are probably pretty small compared to the pressures involved.

Obviously though, you do want any launcher to be safe even in a worst case scenario such as a blocked barrel - if the construction leaves you in any real doubt about whether that would be the case, it would be a good idea to upload some pictures for people to take a look at.
Does that thing kinda look like a big cat to you?
Bigredpotato
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Sun Jan 28, 2018 2:27 am

Ok I a test. Dropping a 30 inch by 1/2 inch dowel rod a distance of about 32 inches down the barrel I was able to move the ball about 3/4 inch.
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jrrdw
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Sun Jan 28, 2018 6:43 am

Ragnarok wrote:Unless you're actually having to seriously force a projectile down the barrel, the frictional forces are probably pretty small compared to the pressures involved.

Obviously though, you do want any launcher to be safe even in a worst case scenario such as a blocked barrel - if the construction leaves you in any real doubt about whether that would be the case, it would be a good idea to upload some pictures for people to take a look at.
Well said and a good rule of thumb. If you don't feel safe you are not. After all you're not rescuing kids that fell through the ice if you know what I mean.
Look if you must.
Air2theBrain
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Sun Jan 28, 2018 7:04 pm

Half the fun is balancing the friction vs resistance.

Nice polished barrel...etc, etc.

I have a foam ball blaster where the balls fit pretty snug, loads of dead space but they launch out the barrel fairly hard. Sometimes you get this nice sound when loading some projectiles into a barrel..just sounds and feels right. :)
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Ragnarok
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Mon Jan 29, 2018 1:18 am

jrrdw wrote:If you don't feel safe you are not.
Indeed. With spudguns, airguns, firearms or any other such things, if you're not sure if it's safe, check, check again, then still treat it like it's dangerous.
Does that thing kinda look like a big cat to you?
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