Copper Marble Cannon

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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al-xg
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Mon Dec 31, 2012 9:13 pm

Fight Club
Das Boot
;)

That is a beautiful shot, the starch patterns are impressive.
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MrCrowley
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Tue Jan 01, 2013 2:53 am

Just saw this (linked by the well-known blogger 'Bad Astronomer') :)
http://www.slate.com/blogs/behold/2012/ ... hotos.html

Nice work with the new photos, I think the banana one is my favourite of the lot.
And I am curious about the photograph for Mr Crowley. It's just a strange little picture. Who, what, were is it from?
As al-xg has said above, it's from the movie Das Boot. Specifically, the 2nd Lieutenant played by the actor Martin Semmelrogge. If you love a good war film, I can highly recommend the Das Boot director's cut version in German with English subtitles.
cometboy
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Tue Jan 01, 2013 9:47 am

Mr Crowley, al-xg

Thank you for the explanation.

As far as the banana, in my experience if you shoot a lot of stuff, some pictures turn out. Maybe one in five. And out of those that turn out, a few turn out good.

The banana shot above is good.

It's the high speed version of "spray and pray"

Cheers.
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jackssmirkingrevenge
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Tue Jan 01, 2013 10:01 am

cometboy wrote:I ran it up to 200psi and shot a few bearings. Much faster, I don't have velocity numbers but it goes through ~100% more plywood, about 1".
That makes sense, as I said before, double pressure and double the energy.
Here is a banana at 110psi. I like it.
Love it, especially the fact that the bearing is clearly visible!
First what revenge is jack smirking about?
[youtube][/youtube]

Alas I was going through a bit of a nihilistic phase when I joined this forum

. :roll:
hectmarr wrote:You have to make many weapons, because this field is long and short life
cometboy
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Sun Jan 20, 2013 8:41 pm

I have slowly been putting together a higher pressure set-up for the steel bearing throwing cannon and got a speed reading a little while ago.

At about 200psi the speed is 680fps, much higher than the ~120psi/520fps from the standard air compressor. I don't have any pictures shot at the higher velocity but the two below are with the lower pressure set-up.

I have not been in any hurry to build the higher pressure set-up since the lower pressure results are pretty much good enough.

<a href="" title="Jumping Jellyfish by alan_sailer, on Flickr"><img src="http://farm9.staticflickr.com/8496/8365 ... 70398c.jpg" width="500" height="282" alt="Jumping Jellyfish"></a>

Above a christmas bulb with colored tempera paint inside.

<a href="" title="Green Eyes by alan_sailer, on Flickr"><img src="http://farm9.staticflickr.com/8229/8396 ... 10f72c.jpg" width="500" height="307" alt="Green Eyes"></a>

A ceramic dolls head filled with clear gelatin.

Cheers.
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jackssmirkingrevenge
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Mon Jan 21, 2013 1:08 am

cometboy wrote:A ceramic dolls head filled with clear gelatin.
... and my new wallpaper, fantastic!
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Brian the brain
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Tue Jan 22, 2013 9:45 am

The ceramic dolls head picture is just epic!

Do you have slowmo footage of that one?
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
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mark.f
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Tue Jan 22, 2013 6:23 pm

As I recall, these are strobe shots... probably no slomo footage (of the same shot).
cometboy
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Tue Jan 22, 2013 6:39 pm

Brian,

Video could be done but my hobby does not support a 30,000$ (new) price for a good color high speed camera.

In any case, what you gain in multiple pictures you lose in resolution. Like any engineering issue it's all about compromise.

I had a friend who has intermittent access to a high speed video camera come by last year. This doll head was not shot, it was exploded...



Cheers.
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jackssmirkingrevenge
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Tue Jan 22, 2013 6:41 pm

HAHA! Love how the eyes come off intact, brilliant!
hectmarr wrote:You have to make many weapons, because this field is long and short life
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