| Author |
Message
|
| CpTn_lAw |
Posted: 03/09/2008 13:22 PM Post subject: |
|
|
 Colonel

Joined: 11 Sep 2005 Posts: 539 152.95 Spud Bux
|
| That is quite a super lot of power here...but in a way, it's a great pain in the a** to build a cap. bank this big, even to get such killer results.
|
|
| Back to top |
|
 |
|
|
 |
| DYI |
Posted: 03/09/2008 13:32 PM Post subject: |
|
|
 Rear Brigadier

Joined: 07 Jul 2007 Posts: 2308 1164.60 Spud Bux
|
| I'm very thankful that someone made one of these, because mine will never be this powerful, and at the rate I'm going, it'll literally be years before I complete it. Supersonic wouldn't surprise me at all with a design like this.
|
|
| Back to top |
|
 |
| Larda |
Posted: 03/09/2008 23:01 PM Post subject: |
|
|
 Corporal

Joined: 18 Jul 2007 Posts: 77 214.73 Spud Bux
|
I made another more successful attempt to measure the velocity today.
I added several layers of sheet metal to the pendulum to make it "bullet proof".
The projectile penetrated two pieces of 20mm wood, two pieces 3mm aluminium, and finally 5mm of steel before it disintegrated.
In this test i charged the capacitors to their surge rating 1350v, for a total energy of 36,5Kj.
High Speed video of the test, its captured at 100FPS but the resolution is lower.
http://www.vimeo.com/769985
The failed test earlier.
http://www.vimeo.com/770135
| Description: |
| Damage by a 90g 12mm Solid Carbide projectile. |
|
| Filesize: |
104.68 KB |
| Viewed: |
81 Time(s) |

|
| Description: |
|
| Filesize: |
88.75 KB |
| Viewed: |
59 Time(s) |

|
| Description: |
| The projectile turned into shrapnel after impact. |
|
| Filesize: |
91.81 KB |
| Viewed: |
63 Time(s) |

|
| Description: |
| Damage by a 90g 12mm Solid Carbide projectile. |
|
| Filesize: |
92.17 KB |
| Viewed: |
72 Time(s) |

|
| Description: |
|
| Filesize: |
76.83 KB |
| Viewed: |
54 Time(s) |

|
|
|
| Back to top |
|
 |
| MrCrowley |
Posted: 03/09/2008 23:21 PM Post subject: |
|
|
 Blizzard of Ozz

Joined: 23 Jun 2006 Posts: 6122 3132.86 Spud Bux
|
HOLY MOTHER OF GOD!
|
|
| Back to top |
|
 |
| Killjoy |
Posted: 03/09/2008 23:36 PM Post subject: |
|
|
Brigadier General

Joined: 11 Nov 2006 Posts: 1002 710.97 Spud Bux
|
| Good god, thats beautiful.
|
|
| Back to top |
|
 |
| chartreusesnot |
Posted: 03/09/2008 23:50 PM Post subject: |
|
|
 Sergeant

Joined: 05 Jun 2007 Posts: 97 0.54 Spud Bux
|
| anybody else noticing the completely massive recoil? It appears to be launching bricks and those square metal bars backwards...
|
|
| Back to top |
|
 |
| Larda |
Posted: 03/09/2008 23:59 PM Post subject: |
|
|
 Corporal

Joined: 18 Jul 2007 Posts: 77 214.73 Spud Bux
|
| chartreusesnot wrote: | | anybody else noticing the completely massive recoil? It appears to be launching bricks and those square metal bars backwards... |
| Description: |
|
| Filesize: |
80.42 KB |
| Viewed: |
63 Time(s) |

|
|
|
| Back to top |
|
 |
| chartreusesnot |
Posted: 03/10/2008 0:07 AM Post subject: |
|
|
 Sergeant

Joined: 05 Jun 2007 Posts: 97 0.54 Spud Bux
|
| Dude... whats happening in that picture? did the recoil split that brick...?
|
|
| Back to top |
|
 |
| Rokmonkey |
Posted: 03/10/2008 0:16 AM Post subject: |
|
|
Corporal

Joined: 28 Feb 2007 Posts: 69 187.75 Spud Bux
|
| Holy Mary mother of God...
|
|
| Back to top |
|
 |
| Novacastrian |
Posted: 03/10/2008 0:31 AM Post subject: |
|
|
Bloody Aussie

Joined: 11 Aug 2007 Posts: 1622 116.11 Spud Bux
|
I herewith change my sig, sorry DYI but this truly takes the cake
|
|
| Back to top |
|
 |
| Copperboy |
Posted: 03/10/2008 1:21 AM Post subject: |
|
|
 Specialist

Joined: 29 Dec 2005 Posts: 47 120.43 Spud Bux
|
Satan i Gatan!!
How did you machine your "chamber"? Nice work!
|
|
| Back to top |
|
 |
| jackssmirkingrevenge |
Posted: 03/10/2008 4:26 AM Post subject: |
|
|
 space monkey

Joined: 15 Mar 2007 Posts: 6968 11091.16 Spud Bux
|
That's just spectacular, congratulations!
I love the way the chequer plate pattern is imprinted on the wood in this photo - amazing stuff, keep it up
|
|
| Back to top |
|
 |
| Ragnarok |
Posted: 03/10/2008 8:08 AM Post subject: |
|
|
 Lord of Karma

Joined: 19 Dec 2006 Posts: 2523 6771.48 Spud Bux
|
Well, that sort of puts things into perspective. DYI has been well and truly beaten on the penetration front.
From that video, and guessing from the markings on your back board, it looks like you're doing about 260-270 m/s (860-880 fps), which is around 3200 Joules (2400 ft-lbs) of kinetic energy. That's a phenomenal amount from a 12mm barrel of that length, and it would seem you're achieving an average pressure of around 10000 psi - possibly more, I'm not sure how long your barrel is, so I guessed around 40 cm from the picture in the opening post - which is a full order of magnitude above anything anyone else has yet achieved (at least, that I can think of).
So, it's not actually supersonic, only about 80% of the way there, but no doubt if you used a projectile of somewhere under 50 grams, you could manage to break the sound barrier.
It's also a respectable 11% efficiency. Ooh, I can see more of these being made.
You sir, have what is no doubt one of the most kick-ass spudguns ever.
|
|
| Back to top |
|
 |
| starman |
Posted: 03/10/2008 8:40 AM Post subject: |
|
|
 Big Daddio

Joined: 11 Dec 2007 Posts: 1734 3569.94 Spud Bux
|
I would be interested in the possibililty of adding some water in with the aluminum powder, possibly somewhat little less powder to make room in your chamber. If you added a minimalist (or more even) burst disk, you could experiment with different slurry mixtures and see what works best.
This is based on the aluminum powder flashing to plasma and thus flashing the water to steam. The military has been prototyping the plasma/steam combo for several years and it supposedly has multimach potential if configured correctly. It may require more power to work properly than you have here, but, maybe not.
Again, very impressive work!
|
|
| Back to top |
|
 |
| DYI |
Posted: 03/10/2008 8:55 AM Post subject: |
|
|
 Rear Brigadier

Joined: 07 Jul 2007 Posts: 2308 1164.60 Spud Bux
|
I tip my hat to you sir, you've achieved what most of us will only ever dream of
I have to get my ass in gear on the [redacted] project now...
|
|
| Back to top |
|
 |
|
|