Help needed with O2 and C3H8

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.
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DYI
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Sun Jun 01, 2008 5:14 pm

That depends how strong it is. If it is designed to survive a detonation at whatever mix you're using, there shouldn't be any trouble standing beside it when it fires with an oxygen mix.
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SpudFarm
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Sun Jun 01, 2008 5:26 pm

i meant the first times..
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jimmy101
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Sun Jun 01, 2008 5:28 pm

BC Pneumatics wrote:Also, a chrony could easily measure a 2.5% change in the ~400fps most cannons shoot.
Really? I've never seen accuracy and precision numbers for a Chrony but 2.5% is certainly possible.

Actually, I wasn't referring to the Chrony's accuracy, I was referring to the shot-to-shot variability of a combustion spudgun. The average spudder can't get the gun to fire with 2.5% reproducibility. So, it really doesn't matter how accurate the chrony is, you can't measure a change of 2.5% in the performance of a combustion spudgun. Latke with his gasketed slug was getting ~3% standard deviations on five to ten replicates (shots). With spuds as ammo the SD was more like 7%.
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Sun Jun 01, 2008 5:40 pm

chrony= 99% on mark
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clide
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Sun Jun 01, 2008 8:34 pm

jimmy101 wrote:Really? I've never seen accuracy and precision numbers for a Chrony but 2.5% is certainly possible.
Just in case you were interested in the actual number, Chrony claims 99.5% accuracy. http://www.shootingchrony.com/manual_F1 ... tech_specs
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jimmy101
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Sun Jun 01, 2008 9:09 pm

Wow, Chrony claims less than 0.5% error (actually reproducibility) for a single shooting session.

Now if we just had guns that could be fired at anywhere near 0.5% reproducibility.
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Philbob1
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Mon Jun 02, 2008 5:11 pm

*cough* *cough* Sorry for my ignorance, but would anyone mind to explain me what in the hell is a Chrony? :D

EDIT: Nevermind, checked out on the site.
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