If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #4390
Joined: Sat Feb 04 2012, 02:39PM
Location:
Posts: 1
A little background: I'm currently an electromechanical engineering tech. student, However, I've never been good with the theory side of things which does tend to cause me some problems sometimes.
We've been doing stuff with magnetics the last couple of weeks in one of our classes and it's sparked discussion of coilguns. Now a small group of us would like to get together and build one (Namely me) but with all the searching and reading I've been doing, I still really have no idea how to start building one, what kinds of voltages I'll need, and what sorts of parts.
Not only that I don't really want to just copy someone elses design, but would like to actually do some of the math on this and learn a few things along the way.
So what are the important variables needed to fire a projectile far and fast?
Registered Member #2063
Joined: Sat Apr 04 2009, 03:16PM
Location: Toronto
Posts: 352
all the stuff you need to make a coil gun -the coil it self -heavy duty switch -plastic tube -disposable camera charging circuit along with the capacitor
there are quite a few simple coil gun tutorials on the internet like this one here -> just remember not to touch the capacitors when they're charged
for the math part, theres only 2 equations that I can think of right now.
Energy stored in a capacitor = 1/2(capacitance)(voltage)^2 energy in Joules, capacitance in Farads, voltage in volts
Kinetic energy of a moving object = 1/2(mass)(velocity)^2 energy in Joules, mass of projectile in Kg, velocity in meters per second
in theory if a coil gun is 100% efficient, it should convert all of the energy stored in the capacitors to kinetic energy of the projectile but in practice, you would be lucky if you can even get 4 to 5% efficientcy
Registered Member #4081
Joined: Wed Aug 31 2011, 06:40PM
Location: UK
Posts: 139
For a coil I used a pen barrel and the wire from an inductor I found. The switch was a door switch from a microwave, still going well after 50+ shots. And to run a camera charging circuit faster use a small wall wart from 3 - 12V at <2A. Use the largest wire you can, it will deliver the power faster then. Projectiles were nails and screws.
Registered Member #1451
Joined: Wed Apr 23 2008, 03:48AM
Location: Boulder, Co
Posts: 661
For hobby projects, these are the average specs: 330V (easily attained from mains) ~4,000uF capacitor bank 18 to 14 awg SCR for the switch 1in long projectile ~100uH coil
To get a great idea of theory, look around Barry's site. Google barry coilgun to find it.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
New to these things, would like to build one.
