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Registered Member #2906
Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727
"Must be on a site somewhere"
Good design attracts veryone.. Good electronics attracts just us here...
Btw: i would really love to get some numbers from this design.. I am interested in efficiency and velocity and projectile energy and so on.. this is data that is not accessible.. I think this should be more important than good looking photos.. or at least equal important.. i hope this does not make me an outsider
Registered Member #1062
Joined: Tue Oct 16 2007, 02:01AM
Location:
Posts: 1529
Great Job! Especially with making 4 of those large capacitors look so small.
Are you holding the capacitors by the screw terminals? I would add more support if you are. The 400v 3900uf capacitors don't have the best attachments.
Registered Member #1525
Joined: Mon Jun 09 2008, 12:16AM
Location: America
Posts: 294
GhostNull wrote ...
Your video has got +112,276 views in one week! Nice! This thread has also got a ton of views.
Great work! This must be on some site somewhere. How about you submit it to Hack A Day?
I sent it to Hacked Gadgets, and from there Gizmodo and PopSci picked it up. I think popularity bubble burst already though, since today had only half as many views as yesterday.
DerAlbi wrote ...
"Must be on a site somewhere"
Good design attracts veryone.. Good electronics attracts just us here...
Btw: i would really love to get some numbers from this design.. I am interested in efficiency and velocity and projectile energy and so on.. this is data that is not accessible.. I think this should be more important than good looking photos.. or at least equal important.. i hope this does not make me an outsider
Greetings
Too true! My electrical engineering really isn't too extraordinary, it's a very simple design. I think it's the video-game look that's gotten the attention.
Sadly, I don't have THE most important numbers- projectile velocity and overall efficiency, due to a lack of funding for a chronometer. But since I start work in a few weeks, I promise I'll have those numbers for everyone ASAP.
rp181 wrote ...
Great Job! Especially with making 4 of those large capacitors look so small.
Are you holding the capacitors by the screw terminals? I would add more support if you are. The 400v 3900uf capacitors don't have the best attachments.
For the most part they are just held on by the screw terminals. But there's enough friction with the body work that when I unscrew one, it takes a good bit of force to pull it loose. Thanks for the warning though, I am somewhat paranoid of getting electrocuted.
Registered Member #2906
Joined: Sun Jun 06 2010, 02:20AM
Location: Dresden, Germany
Posts: 727
The easiest way for you to detrmine the velocity would be that you place 2 sheets of paper in a distanace of 1..3m. Then you can record the sound with a simple microphone that is in the middle of these papers. If you shoot, and you samplingrate of your recording is high (96kHz?) you should be able to see the shootthroughs in the waveform Should be quite easy for you.. its doable with a headset afaik.
The mass of the projectile could be determined by volume*density. Volume of an irregular body is easyly determined by how much water rises in a measuring cup..
Very cool! I wanted to make one a couple years ago and never found time to get started. After looking around this site, I might have to finally give it a shot.
For the velocity, have you thought about posting on a firearms forum? I don't know where your located but most reloaders will have a chronograph and a reloading scale. I'm sure someone in your area would let you use theirs, just post up that video.
Registered Member #2648
Joined: Sun Jan 24 2010, 12:45PM
Location: Australia
Posts: 291
For anyone setting out to build a coilgun I strongly recommend you vist: and READ READ READ
Coil guns aren't techincally firearms as they do not use an exsplosive force to propell a projectile. Coil guns are also pretty impractical, a bow and arrow would likely have more power than a coil gun. Coil guns are just something you build for coolness and learning
Registered Member #1525
Joined: Mon Jun 09 2008, 12:16AM
Location: America
Posts: 294
GhostNull wrote ...
For anyone setting out to build a coilgun I strongly recommend you vist: and READ READ READ
Coil guns aren't techincally firearms as they do not use an exsplosive force to propell a projectile. Coil guns are also pretty impractical, a bow and arrow would likely have more power than a coil gun. Coil guns are just something you build for coolness and learning
Wow, thanks. Hopefully people will come here and read this. I should have put that on my video description- most people don't understand that and are all like "LUL UR T3h suck cuz I could doo more damage with a (instert whatever here)".
Killa-X wrote ...
Nice design! Never fear those capacitors ever risking a possibly explosion I take it? I like the small compact design, looks really good!
I plan to make one, like your voltmeter on the side! I plan to do a 980Kj coilgun. I have 800v 300A stud diode and 1200v 650A scr. Should be good!
Nah they won't explode, not unless I hook the charger up backwards somehow. I hope you mean 980J, cus 980kJ is bigger than the deadly-weapon coilgun the army built and would certainly blow your SCR to pieces. But none the less, best of luck on your project!
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Portable 1.25kJ coilgun finally done
I think this should be more important than good looking photos.. or at least equal important.. i hope this does not make me an outsider 
