28,8Kj ElectroThermal Gun! (Soon handheld)
To start with i must say that aim not sure if this is the right place to post this, it doesn't fit in any of the categories.
So please feel free to move this if its in the wrong place.
Some time ago i started building a fairly large capacitor bank that aim planing to use for my rail-gun project.
Its consist of 24, 15000uF 400v capacitors for a total energy of 28800 Joules.
The capacitors are arranged in 3 parallel banks that are wired in series for 1200v and 40000uF.
To test the capacitor bank i decided to build a ElectroThermal Gun.
The ETG (ElectroThermal Gun) works by discharging the capacitor bank threw fine aluminium powder and foil inside a chamber.
The electric current then heats the aluminium enough to make it evaporate and turn into plasma.
When the aluminium turns into superheated plasma it expands and the pressure in the chamber increases, the plasma also heats the air so it expands.
The expanding gases then force the projectile down the barrel like a conventional (spud)gun.
The ETH have a 12mm smooth-bore barrel that is screwed into a steel chamber with a electrode that goes threw a insulator in the end, the power is then feed into that electrode and threw the aluminium-powder.
Some videos.
Test shot 1:
http://www.vimeo.com/751433
Test shot 1, Second view:
http://www.vimeo.com/751469
Test shot 2:
http://www.vimeo.com/751476
I hope you like it,
If i made any typos please don't kill me, my English is not so good and its 6AM so i really need to get some sleep. :sleepy1:
Edit:Typos
So please feel free to move this if its in the wrong place.
Some time ago i started building a fairly large capacitor bank that aim planing to use for my rail-gun project.
Its consist of 24, 15000uF 400v capacitors for a total energy of 28800 Joules.
The capacitors are arranged in 3 parallel banks that are wired in series for 1200v and 40000uF.
To test the capacitor bank i decided to build a ElectroThermal Gun.
The ETG (ElectroThermal Gun) works by discharging the capacitor bank threw fine aluminium powder and foil inside a chamber.
The electric current then heats the aluminium enough to make it evaporate and turn into plasma.
When the aluminium turns into superheated plasma it expands and the pressure in the chamber increases, the plasma also heats the air so it expands.
The expanding gases then force the projectile down the barrel like a conventional (spud)gun.
The ETH have a 12mm smooth-bore barrel that is screwed into a steel chamber with a electrode that goes threw a insulator in the end, the power is then feed into that electrode and threw the aluminium-powder.
Some videos.
Test shot 1:
http://www.vimeo.com/751433
Test shot 1, Second view:
http://www.vimeo.com/751469
Test shot 2:
http://www.vimeo.com/751476
I hope you like it,
If i made any typos please don't kill me, my English is not so good and its 6AM so i really need to get some sleep. :sleepy1:
Edit:Typos
- Attachments
Last edited by Larda on Sat May 03, 2008 9:42 pm, edited 2 times in total.
Good god thats incredible. I've heard of these discussed but never actually seen a finished working one.
Thats incredible, nice work.
Thats incredible, nice work.
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"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
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- Davidvaini
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I only see 1 bank in that lower picture... where are the other caps?
Also what gauge wire is that leading to the gun?
Also what gauge wire is that leading to the gun?
- jackssmirkingrevenge
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Fork in hell, that's brilliant
"The expanding gases then force the projectile down the barrel like a conversational (spud)gun."
When you're spending enough time in your workshop for your projects to start talking to you, definitely time for some fresh air the word is "conventional". But it's just a silly typo, with launchers like that you can make all the typos you want, can't wait to see that railgun
Is that the same railgun you have built this pneumatic for?Some time ago i started building a fairly large capacitor bank that aim planing to use for my rail-gun project.
I'm just going to pick on one if I may, 'cause it's hilarious:If i made any typos please don't kill me, my English is not so good and its 6AM so i really need to get some sleep.
"The expanding gases then force the projectile down the barrel like a conversational (spud)gun."
When you're spending enough time in your workshop for your projects to start talking to you, definitely time for some fresh air the word is "conventional". But it's just a silly typo, with launchers like that you can make all the typos you want, can't wait to see that railgun
hectmarr wrote:You have to make many weapons, because this field is long and short life
Looks like 4 gauge but I could be wrong. I forgot to ask, whats yourAlso what gauge wire is that leading to the gun?
projectile?[/quote]
Stanford Class of 2012
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
"In the end our society will be defined not only by what we create, but what we refuse to destroy"- John Sawhill
Ohh, i meant 3 rows that are wired in series, only one bank so fare.Davidvaini wrote:I only see 1 bank in that lower picture... where are the other caps?
Also what gauge wire is that leading to the gun?
But i have enough capt to built at least to more identical banks.
I use 35mm2 cables, that's about AWG 2, but aim planning to upgrade to at least two in parallel.
Last edited by Larda on Fri Mar 07, 2008 12:22 am, edited 1 time in total.
- Davidvaini
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Id say get 2 banks and up the power... Your base seems to be able to support it and 2 banks would create 4X more power
but over all its very decent and looks like a good little project you have going on.
but over all its very decent and looks like a good little project you have going on.
I used two projectiles, first was a broken Center drill, the second a broken solid carbide drill, really hard and really heavy.Killjoy wrote:Looks like 4 gauge but I could be wrong. I forgot to ask, whats yourAlso what gauge wire is that leading to the gun?
projectile?
jackssmirkingrevenge:
Thanks for the correction. Sometimes the spellcheck choose the wrong word.
Last edited by Larda on Fri Mar 07, 2008 12:36 am, edited 1 time in total.
- Lentamentalisk
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Really nicely done! My friend and I are working on building a Cap bank and dis/charging circuit, mainly for our microwave gun, but we will also be testing it on on an ETG.
Why is it that everyone all of a sudden is making ETGs?
Yet again, very nicely done!
Why is it that everyone all of a sudden is making ETGs?
Yet again, very nicely done!
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Live life in the present, and make it so beautiful that it will be worth remembering.
- jackssmirkingrevenge
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Ragnarok's going to cream his pants when he sees this
could we have some more detailed damage pics?
could we have some more detailed damage pics?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Effin wow, thankyou very much for making me aware of your project I will not for one second pretend that i know the faintest about what you have built but <GOD> that is some nice (stuff that words can't describe).
I agree with JSR, come on Rag where are you homeboy-Check this sh!t out!
Edit: Alright so i know how it works, but but but but i gotta get me one of those It looks so sick.
I agree with JSR, come on Rag where are you homeboy-Check this sh!t out!
Edit: Alright so i know how it works, but but but but i gotta get me one of those It looks so sick.
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When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
*Little fruit machine noise as head pops into view*Novacastrian wrote:I agree with JSR, come on Rag where are you homeboy
Answer: At that time, asleep, and I don't have JSR's superhuman powers to be on the forum as he sleeps (if he even does...)
There's not really much I can say to that wonderful piece of work - No real suggestions for improvement (at least, not practical ones.)
What I can say is that, I don't quite get Davidvaini's "2x cap bank = 4x power" theory - electrical power, possibly, if they were wired in series (but not quite - inductance and heating would slightly blunt the electrical power, but it would increase in that sort of region).
However, assuming we're talking about kinetic energy, no - that would require a doubling of efficiency, and by that logic, you could break 100% efficiency by just adding enough banks.
Well, I'm certainly impressed, and I'm looking forward to seeing either your next project - or any more info on this one. :thumbleft: - Not quite the right emoticon, but they don't do a suggestive "smile, thumbs-up and nod" one, that'll have to do.
Does that thing kinda look like a big cat to you?
Thanks for your comments, everyone!
Lentamentalisk:
What voltage and capacitance are you using?
Any link?
Here is a few more damage pics, really not that detailed but i can take some more this weekend when i do some more shots.
Lentamentalisk:
What voltage and capacitance are you using?
Any link?
Here is a few more damage pics, really not that detailed but i can take some more this weekend when i do some more shots.
- Attachments
-
- Second projectile made out of a broken solid-carbide drill. Weight 72.6g
Its 12.00mm and the ID of the barrel is 12.04mm. - projectile.jpg (25.97 KiB) Viewed 37454 times
- Second projectile made out of a broken solid-carbide drill. Weight 72.6g