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This is roughly as powerful a coil gun as you can make using a standard mains switch. To make a more powerful coil gun you will need a higher rated switch, preferably solid state.
Through much research I found all the Variables that affect the efficiency of a coil gun:
Projectile
Length
Stabilisation
Diameter
Length to diameter ratio
Material
Conductivity
Aerodynamics
Initial Positioning
Mass
Flux Linkage
Coil
Length
Number of layers
Thickness of wire
Flux linkage
Current Pulse length
Switch bounce and resistance
Capacitor Voltage and Capacitance
Overall wire length and diameter used.
Also there are several ways to increase standard performance using:
Optical, Inductive or Physical Triggering
Multiple stages
Super cooling
Through much research I found all the Variables that affect the efficiency of a coil gun:
Projectile
Length
Stabilisation
Diameter
Length to diameter ratio
Material
Conductivity
Aerodynamics
Initial Positioning
Mass
Flux Linkage
Coil
Length
Number of layers
Thickness of wire
Flux linkage
Current Pulse length
Switch bounce and resistance
Capacitor Voltage and Capacitance
Overall wire length and diameter used.
Also there are several ways to increase standard performance using:
Optical, Inductive or Physical Triggering
Multiple stages
Super cooling
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Signing UpStep 1The Plan
I had some 6mm steel bar, some 6mm plastic pipe, a micro switch and some enamel coated wire as a starting point.
I took apart 17 disposable cameras and soldered the capacitors in parallel to form a capacitor bank of 1360uF 330v which using E=1/2CV^2 gives a stored energy of 73J.
I used one of the camera circuits as a charging circuit by removing the flash, removing the trigger switch and soldering the charge switch closed.
I then used an old mains PSU switch as a charging switch although any switch will do. The whole circuit was covered thouroughly in insulation tape and put in the only plastic box of the right size I could find at the time; An empty Bertolli spread box.
I wrapped a coil out of 26AWG enamel coated wire 30mm long and 7 layers thick. This is because the coil should be the same length as the projectile and the projectile should be five times longer than it is wide, hence 5x6=30. The number of layers is dependant on wire thickness and capacitor bank size and voltage. The thinner the wire, the smaller the bank, the less layers. wire too thin will impede flow and maybe burn out. Wire too thick will mean you have less coil density than is potentially attainable.
Simulations ran well after the device was constructed reveal this isn't an optimal design and there is some 'suck back' as you can see on the graph when the turquoise line falls bellow the axis suddenly.
I took apart 17 disposable cameras and soldered the capacitors in parallel to form a capacitor bank of 1360uF 330v which using E=1/2CV^2 gives a stored energy of 73J.
I used one of the camera circuits as a charging circuit by removing the flash, removing the trigger switch and soldering the charge switch closed.
I then used an old mains PSU switch as a charging switch although any switch will do. The whole circuit was covered thouroughly in insulation tape and put in the only plastic box of the right size I could find at the time; An empty Bertolli spread box.
I wrapped a coil out of 26AWG enamel coated wire 30mm long and 7 layers thick. This is because the coil should be the same length as the projectile and the projectile should be five times longer than it is wide, hence 5x6=30. The number of layers is dependant on wire thickness and capacitor bank size and voltage. The thinner the wire, the smaller the bank, the less layers. wire too thin will impede flow and maybe burn out. Wire too thick will mean you have less coil density than is potentially attainable.
Simulations ran well after the device was constructed reveal this isn't an optimal design and there is some 'suck back' as you can see on the graph when the turquoise line falls bellow the axis suddenly.
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The PSU switch is just a switch, any switch will do. Mine was out of an old computer power supply unit (PSU) I used to get broken ones free from the IT support department at the university. Your schools IT department may have one. If so be careful when dismantling as the have high voltage capacitors in them. If in doubt, consult a responsible adult and or chicken out. Better to not have the parts than be dead.
The coil gun system is very similar to a transformer. When you dump all that electricity into the coil a massive magnetic field is generated around the coil which is was attracts the ferrous projectile into the coil. When the electricity runs out or the switch is broken, the magnetic field collapses and the projectile de-saturates. This is how a transformer works, The varying magnetic field induces a current in the coil. So when the field collapses a current is induced which can break your components such as capacitors by charging them backwards. The diode is there so that the electricity can go back into the coil and dissipate rather than frying your expensive caps and solid state switches.
http://www.maplin.co.uk/low-cost-standard-microswitches-6453
I would suggest you use a 12v to 240v inverter and a small battery as your power source rather than messing with the actual mains though as mains is incredibly dangerous as it happens to be at roughly the right AC frequency to stop your heart and there's an unlimited supply of it out of a socket.
You should use half wave rectification to limit the power available and put a reasonably large charge resistor in the way to stop the cap charging too quickly. I have used a standard 40W bayonet light bulb for that previously because it offers non-linear charge resistance. Make sure it's all in a double insulated box and you need a tool to open it. No metal touchable on the outside etc. Check my 50cal for instructions. That is the charge circuit I used on it.
In plain English; Yes, but I would need to know the specifics of the charger and the capacitor being charged and how you intend to do the charging. Monitoring the temperature of the capacitor and the voltage across the capacitor is important when using a charger not intended for capacitors as to avoid damaging you or your caps.
thanx! :D