Using a fan

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.
miskaman
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Mon Jul 02, 2007 11:36 pm

I heard you can use a fan in a combustion chamber to help air it out after a shot. So when you actually are firing the gun, do you have to take the fan out, or can you leave it in?

And also, what fan would you reccommend for a 4" chamber exactly 12" long. It would be helpful if a link were posted too.
Last edited by miskaman on Mon Jul 02, 2007 11:43 pm, edited 1 time in total.
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spudkilla
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Mon Jul 02, 2007 11:37 pm

Leave it in!


Just a regular brush less computer fan would work well!
Last edited by spudkilla on Mon Jul 02, 2007 11:38 pm, edited 1 time in total.
Why do I try to make a relevant post?
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gotbass7
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Mon Jul 02, 2007 11:37 pm

hey whoa. the fan is filtering the air BEFORE the shot. keep it in definitly.
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noname
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Mon Jul 02, 2007 11:38 pm

People leave the fan in. You may not realize it, but the combustion takes place in literally a fraction of a second, which isn't enough to damage the fan.
Use any fan that fits, the more air it moves, the better.
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spudkilla
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Mon Jul 02, 2007 11:39 pm

gotbass7 wrote:hey whoa. the fan is filtering the air BEFORE the shot. keep it in definitly.


Doesn't he have to fire it in order for there to be gas in the chamber in the first place.....
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gotbass7
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Mon Jul 02, 2007 11:42 pm

isnt it for filtering the fuel with the air?
Obsolescecne is just a lack of imaginaiton-www.accrc.org
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spudkilla
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Mon Jul 02, 2007 11:49 pm

Yes, but also venting your cannon after the shot....
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gotbass7
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Tue Jul 03, 2007 12:06 am

ya but it didnt seem like he knew that its for mixing too
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miskaman
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Tue Jul 03, 2007 12:34 am

Ya, I was just talking about venting.
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BC Pneumatics
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Tue Jul 03, 2007 1:50 am

This is what you need:
http://www.bcvids.com/store/product_inf ... ucts_id=63

You leave it in all the time, and run it before you spray in the fuel, and right before you fire.
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mtronic
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Thu Jul 05, 2007 5:33 am

i went to my local electronics store and picked up a nice 12v fan that fits very tightly(after some taped edges, its wedged in super tight!!! no screw holes) into a 4'' chamber. It cost about AU $12.

Alternativly you could get a smaller 5v fan but then mounting it you'd need to screw it or glue it.

have a look at some of the guys cannons in the album section for ideas?
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