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Prop-Gun idea Answered

I don't have that much confidence in getting this to work, but as an idea I thought I'd share it:
I have a concept of a rotating-barrel automatic-chain-gun, that I can do no problem. BUT, to simulate muzzle-flash, I'm thinking of feeding butane/air down the barrels (blow-lamp type device) and igniting it.
Initially, I think of slip-rings or similar and a camera-flash unit for ignition, motor drive on the barrels.
Any advice?

L

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Jaycub (author)2010-12-13

If you actualy build this you might try using hydrogen insted of butane because it is easier to get the fuel-air mix right, would would make a better sound, and burns with a more realistic orange flame instead of the blue of a butane-air mix.

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Arano (author)Jaycub2010-12-18

hum... if i rember right hydrogen burns with a light blue nearly invisible flame... the orange in most flames is hot unburned carbon... more gas than air and you get a orange flame...

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Jaycub (author)Arano2010-12-18

Mabey if it's pure, but every time I have burned hydrogen it has had an orange or yellowish flame. Mabey it has to do with a laminar vs turbulent flow of the flame or something.

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Arano (author)Jaycub2010-12-19

that shouldn't make a difference for hydrogen... but natrium salts make yellow colored flame (and are rather hard to get rid off, even in a laboratory...) and it is only a very very small amount needed for a strong yellow

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Jaycub (author)Arano2010-12-19

Ok that't probably why then because I use Sodium Hydroxide for making oxyHydrogen by electrolysis, and when making plain hydrogen with NaOH, water, and Aluminum.

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Arano (author)Jaycub2010-12-19

to show you how well natrium turns a flame yellow try this: light a bunsenburner or similar device that burns gas with the hot blue flame, hold a piece of metall or magnesia into the flame until it is really hot and hold it into a small amount of your sodium hydroxide solution that is about 20-30cm away from the burner... the flame should turn yellow for a short time... (works well with every sodium salt)

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kelseymh (author)Jaycub2010-12-13

Dude, if you had just waited four more days, your reply would have looked even less like a bump :-D

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KentsOkay (author)2010-12-14

A number of automatic guns used in movies use propane to provide the muzzle flash.
Of course I have failed to find any good linkage on how they work :T

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lemonie (author)KentsOkay2010-12-14


Interesting, I would have thought blank-rounds easier.

L

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KentsOkay (author)lemonie2010-12-14

Shooting .50 BMG gets pricey quick, also other expenses (taxes, ammo, upkeep, weapon costs) are reduced.

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lemonie (author)KentsOkay2010-12-15


Can you point me to such props?

L

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KentsOkay (author)lemonie2010-12-17

Here's one decent mention.
Also check out M134 minigun and rocket pods on the same page.

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lemonie (author)KentsOkay2010-12-17
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KentsOkay (author)lemonie2010-12-17

Yeah, I guess its a wee tad more bammy than propane.

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NachoMahma (author)2009-12-17

.  Drill two holes in a circular plate that is large enough to cover one end of the barrel assembly. It would fit between the barrels and the gas nozzle in your pic with the plate center on the horizontal grey line (barrel assembly rotation axis). Into the "upstream" hole inject your air/fuel mix (attach your nozzle to the plate). Mount a spark plug in the other hole.

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NachoMahma (author)NachoMahma2009-12-17

.  Oh. The plate would be fixed and you would depend on the fit between barrels and plate for a seal. It won't be a great seal, but should be good enough for your purposes. Not sure what to use for a lube between barrel faces and plate - graphite?

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lemonie (author)NachoMahma2009-12-17

I think a small gap would be acceptable. It was the ignition-triggering I was most stuck with, but that idea gives me something to work with, thanks.

L

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NachoMahma (author)lemonie2009-12-17

.  Mount a lever switch so that the barrels open it as they go by. Time it so the sw opens as the a/f filled barrel goes past the spark plug.

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lemonie (author)NachoMahma2009-12-17

I was thinking of olde-fashioned distributor technology, but that's worth thinking about too.

L

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NachoMahma (author)lemonie2009-12-17

.  What I was trying to explain is exactly that. The barrels act like the distributor cam.

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lemonie (author)NachoMahma2009-12-17

Yes, our ideas are converging/ed, the contact-breaker on the barrel, spark-gap distribution. That helps, so thanks again.

L

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NachoMahma (author)NachoMahma2009-12-17

.  Come to think of it, it wouldn't require a large circular plate that would cover the whole end of the barrel assy. Just a plate the would cover the ends of two adjacent barrels.

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lemonie (author)2009-12-17

Why am I not surprised this took 2 days to turn-up...?

L

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