cartridge fed combustion build log

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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jackssmirkingrevenge
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Tue Jan 26, 2010 8:52 am

Ragnarok wrote:Yes. I see you are still talking when there's science to do.* :tongue3:
You forget that during work hours I'm posting from a laboratory so yes, I'm doing science as I speak, just not the projectile firing kind ;)
*Heck, I want to see you start one of your showcase threads with the line "This was a triumph".
The title would be a note on the lines of "HUGE SUCCESS!" :D
...It'd make a change to your usual performance at least.
ImageImage :P

:D :D :D
hectmarr wrote:You have to make many weapons, because this field is long and short life
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deathbyDWV
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Tue Jan 26, 2010 9:12 am

I have been watching this and it looks really good!

A pump action would be soooo cool!

Also, it seems everyone on here has played portal...
Life's too short to mark off the items on your wish list...
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Ragnarok
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Tue Jan 26, 2010 9:24 am

jackssmirkingrevenge wrote:You forget that during work hours I'm posting from a laboratory so yes, I'm doing science as I speak, just not the projectile firing kind.
Well then, there is research to be done.
*Heck, I want to see you start one of your showcase threads with the line "This was a triumph".
The title would be a note on the lines of "HUGE SUCCESS!" :D
I've been listening to that song repeatedly recently. I've got the whole Orange Box soundtrack on my computer - it's hard to overstate my satisfaction with it.
ImageImage
You know, there would have been a better response there... But there's no sense crying over every mistake.
deathbyDWV wrote:Also, it seems everyone on here has played portal...
I'm being so sincere right now - one of the best games <s>of modern years</s> ever.
Does that thing kinda look like a big cat to you?
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psycix
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Tue Jan 26, 2010 1:27 pm

But there's no sense crying over every mistake.
You just keep trying 'till you run out of cake epoxy.
And the science gets done and you make a neat gun

for the people who are still online.

:D



On a side note, I took the liberty to create a steam group for us spudders, since so many of us play games there.
http://steamcommunity.com/groups/spudfiles
Join up! :D
Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
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jackssmirkingrevenge
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Tue Jan 26, 2010 2:44 pm

Here's some science for you :P

[youtube][/youtube]
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 26, 2010 4:08 pm

It seems a bit slow... :D

Huh-huh-huh..


WTH?? no parts came off!

Nice work!

This puts hybrid cartridges within reach..It might me feasable to build 6mm bb firing hybrid cartridged the size of shotgun shells...

That would open up a whole world of design posibilities...


After so many projects dying an early death it's good to see one come alive again..

Image

OMG!! He's an actual zombie..he came back to life after some epoxy experiment turned ugly!! :wink:
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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jackssmirkingrevenge
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Tue Jan 26, 2010 5:34 pm

An oxygen fuelled hybrid would certainly be a reasonable proposition, this prototype has faily crap power but it does make for some good high speed footage :D

[youtube][/youtube]

I might have a play with electrolysis soon, should't be too hard to set up something like this:

Image

on the plus side, you'd also be getting hydrogen, hmm...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Ragnarok
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Wed Jan 27, 2010 5:52 am

jackssmirkingrevenge wrote:on the plus side, you'd also be getting hydrogen
The downside to a H2/O2 mix is that it doesn't actually provide much of a pressure improvement over a straight Propane/Air mix.

Of course, if you mean to use the hydrogen for other things...
Does that thing kinda look like a big cat to you?
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psycix
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Wed Jan 27, 2010 5:58 am

OMG!! He's an actual zombie..he came back to life after some epoxy experiment turned ugly!! Wink
The epoxy must have conserved his physical body and replaced/fixed all neurotransmitters with binary adhesive bonds, forcing the body to stay alive... for ever.
That is not him... it is the epoxy speaking. He has no soul! :lol:


Nice video's, the camera is totally worth its price.
Next time try to film under indescant lights though, the fluorescent lightning flickers.

JSR wrote:I might have a play with electrolysis soon, should't be too hard to set up something like this:
The good old water + electricity trick. I'd recommend stainless steel electrodes and NaOH (drain cleaner) as electrolyte. Carbon electrodes will break up and make the whole water black. Platinum would be better, but hey, if you have the money for that, just buy H2 and O2 cylinders.
Ragnarok wrote:The downside to a H2/O2 mix is that it doesn't actually provide much of a pressure improvement over a straight Propane/Air mix.
But it burns faster and gives better reaction products (H2O instead of H2O + CO2).
Beware of DDT.
Till the day I'm dieing, I'll keep them spuddies flying, 'cause I can!

Spudfiles steam group, join!
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Insomniac
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Wed Jan 27, 2010 6:03 am

Be mindful that when you use stainless steel, you'll probably end up with chromium compounds in the water. At what concentrations will obviously depend on the steel and a myriad of other factors. I'm not sure of how much of a safety issue it is, but it's somthing to keep in mind.
Last edited by Insomniac on Wed Jan 27, 2010 8:47 am, edited 1 time in total.
I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
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jackssmirkingrevenge
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Wed Jan 27, 2010 8:37 am

psycix wrote:That is not him... it is the epoxy speaking. He has no soul! :lol:
Are you suggesting that I will live on forever in an epoxy exoskeletonin a similar manner to Stephen Hawking? :P :D
Nice video's, the camera is totally worth its price.
Next time try to film under indescant lights though, the fluorescent lightning flickers.
Thanks, it's hard to overstate my satisfaction see what I did there :D with the camera! I'm still getting to grips with it so I expect quality will get better, I already started using a halogen lamp and will buy some floodlights as suggested in the high speed thread.
I'd recommend stainless steel electrodes and NaOH (drain cleaner) as electrolyte.
I work in a laboratory that serves a pharmaceutical plant, I have 99% pure NaOH in here and a pallet of 25Kg bags in the plant, I don't think drain cleaner will be necessary :P
Be mindful that when you use stainless steel, you'll probably end up with chromium compounds in the water.
Again I handle chromium waste fairly regularly on account of some of the water quality testing we do so no worries there.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Ragnarok
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Wed Jan 27, 2010 8:40 am

psycix wrote:But [H2/O2] burns faster and gives better reaction products (H2O instead of H2O + CO2).
The first point is of little relevance in a chamber this size and with this kind of ratio.

The second point is also pretty irrelevant at these low velocities.
The lesser density won't count for much here. For one thing, it means the gasses have a lesser heat capacity - they'll cool off quicker, and that's not a good thing in anything like this with such a high internal surface area for its volume.

I wouldn't put any money at all on the hydrogen/oxygen mix being better than the propane/air mix.
Does that thing kinda look like a big cat to you?
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Insomniac
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Wed Jan 27, 2010 8:51 am

jackssmirkingrevenge wrote:Thanks, it's hard to overstate my satisfaction see what I did there :D
I do indeed see what you did there :D



Ragnarok wrote: I wouldn't put any money at all on the hydrogen/oxygen mix being better than the propane/air mix.
You're probably correct there, based on the (very minimal) testing that I did with a hydrogen/oxy mix obtained via electrolysis. The only differences seemed to be an orange flame rather than blue (due to sodium in my electrolyte), and a much louder BANG when fired with no projectile or burst disk :D
I wonder how much deeper the ocean would be without sponges.
Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before.

Add me on msn!!! insomniac-55@hotmail.com
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McCoytheGreater
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Wed Jan 27, 2010 12:09 pm

psycix wrote: Next time try to film under indescant lights though, the fluorescent lightning flickers.
We've found that halogen lights aren't as susceptible to the 50 or 60 hrtz flickering, and not only that, they're bright as hell. Perfect for shooting with a exilem.

EDIT: Gonna read the previous posts next time. The camera is pretty awesome though, and the halogen lights do work.
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