I want to make a coil gun but have 0 experience with electronics and obviously no tools. What would be a good place to start learning or a good first project?
Mercury is a good anti-conductant try sticking your hands in some before starting the experiment.
>>983161
rm -rf nigger
>>983160
There are many great books on electronics for beginners.
I would start with some simple transistor or mosfet circuits, like a riaa amplifier.
You could then look at some switched power converters like buck or boost (remember to load the boost)
There are plenty of options, but first and most important of all, you will encounter a lot of math! And I mean a lot..
Then you will encounter lots of component failure, due to lacking knowledge, this will cost hours and $$..
You would also have to buy/gain access to an oscilloscope.
>>983160
Buy an electronics book and a soldering iron. Then find an old dvd player or something, unsolder it and resolder it (so that it works again)
>>983160
That is a horrible idea unless your goal is a potentially fatal accident.
Simple designs involve capacitors charged to high voltages (300V+ usually) that will kill you.
Low voltage multi stage designs will most likely be too complicated for you.
If you insist on it, start with a low voltage prototype. You'll need to learn about inductors, semiconductors (transistors, thyristors, etc) and either a bunch of math or how to use optic sensors.
>>983171
>a lot of math
I've tried making a mathematical model for a coilgun. Gave up. Too many variables.
Ended up making broad assumptions and simplifications with goal orientated calculations instead of a proper model.
My project is still at the drawing board though, and it's grown to the point where it might as well be a real weapon system. Even planning it to contain self-calibration, so I'm thinking of using power MOSFETs or IGBTs instead of the usual SCRs. Doubt I'll ever actually make it at this point though. Too many expensive components and the frame would need to be cut with a CNC machine which I don't have access to.
If anyone know where to get a mathematical model for the whole physics system, I'd be incredibly grateful. Having big issues trying to calculate the best coil parameters.
>>983160
>tfw i've forgotten most of what i've learned about this shit
Anyway, if i were you i'd start with one coil on a low voltage and make that work, then expand from there on to more complicated designs.
Also this lad made a very basic one
youtube.com/watch?v=mdZo_keUoEs
>>983160
Go and make a sling shot with a rubber band and a tree branch, because that's as close as you'll get moron.
>>983160
This would be probably the best place to start, lots of information and designs to go off of. But as others said a lot of math and understanding of components and potentially lethal voltages
http://www.coilgun.ru/
>>983184
>Simple designs involve capacitors charged to high voltages (300V+ usually) that will kill you.
Unlikely, unless you have preexisting issues or put the leads across your heart.
I've made a few using 330v caps and shocked myself a few times, since electricity will take the path of least resistance I just ended up startled and two burn marks on a finger.
OP: You can make a fun hobby one using disposable camera capacitors. That is how I started out, then eventually moved to multi-stage designs.
The single stage one I had with a bunch of camera caps could put a sharpened .22 sized slug through both sides of a popcan.
>>983206
Very unlikely if touched with one hand, true. A whole other matter if touched with both so the current has to pass your torso.
I have always had an idea, that coil guns are super ineffective.
Not because of losses and such. But due to the method of energy transferral.
You apply a current to an inductor, generate a field, and propell a magnetic projectile. But it is not possible to remove the field of the inductor when the projectile has reached the center (or max velocity).
Hence the field in the inductor will decelerate the projectile once it moves past the center of the inductor..
Please correct me if I am wrong.
>>983244
The suckback (or whatever is the proper term) you're talking about can be mitigated with proper math or control circuitry.
But they are horribly ineffective, for a whole bunch of reasons.
>>983244
Most of the issue is magnetic saturation of the projectile; you can't really apply any more force at that point, so the only way to get an efficient, effective coilgun is a long, many-staged accelerator with a large, heavy, relatively slow projectile.
Railguns skirt by this limitation because the magnetic field of the accelerator acts upon the induced magnetic field in the projectile, which has no inherent limit.
>>983301
>the magnetic field of the accelerator acts upon the induced magnetic field in the projectile, which has no inherent limit.
What? I thought in a railgun there was a "stationary" magnetic field along the barrel with a current going through the projectile producing a force a la F=I.B.L
Please correct me if i'm wrong
>>983161
bait/10
>>983184
>300V+ usually) that will kill you.
just no.
amps kill, volts dont.
Ive touched mains voltage on accident several times, Im fine.
Ive accidently shocked my hand with sparkplug wires, Im fine (those are 10,000 - 20,000 volts)
Tazers are 10k-50k volts maybe more.
>>983316
I'd like to add that AC is far more dangerous than DC because a wide range of frequencies tend to mess with your nerve system.
So getting killed by a coilgun is probably pretty hard.
>>983324
Oh yes, I forgot to mention that ac will wreck your shit 10 times faster.
>>983301
>magnetic saturation of the projectile
That's why any actual research made on coilguns focuses on inductive projectile designs.
>>983310
There's no "stationary" magnetic field. Only the fields created by the current going through the rails and the projectile. Look up Lorentz force.
>>983316
Yes, amps kill. And uncle Ohm says voltage is what will make those amps happen. The beefy capacitors in coilgun projects have more than enough capacity for a shock lasting at least a few seconds.
Sparkplugs have very limited current since they only need a spark, not a plasma arc and tazers are literally designed to limit the current to safeish levels.
>AC is far more dangerous than DC
Arguing on which is more dangerous is a bit of a moot point when both are potentially lethal. Especially on /diy/ where some idiot will get the impression that "safer" is the same as "safe".
Seriously, could /diy/ fucking stop with the whole amps vs volts thing? It's like no one even bothers learning and are just repeating the same meme.
>>983286
The math and control must be really difficult to realize. The most tiny delays in your feedback loop could ruin the timing..
And also the inductance of a coil this size, will cause a time constant which is high, making the control and timing even more difficult..
Especially as the inductance is not constant, due to the moving projectile.
>>983316
https://www.youtube.com/watch?v=8xONZcBJh5A
>>983324
Okay, Tom. Why don't you and your elephant prove it?
>>983161
overly scared millenial bait/10
Having mercury on your hand, or your hand in mercury will probably yield no damage at all. It's the salts you should be scared of, and even still then mercury poisoning is overrated.
What's a good program to model and calculate the magnetic field created by a solenoid?
>>983526
yhea it's unless digested, it's only organic mercury you need to worry about
organic mercury is however extremely poisons, and can be absorbed through skin
>>983244
> But it is not possible to remove the field of the inductor when the projectile has reached the center (or max velocity).
It's entirely possible, you just need actual control circuitry rather than connecting a capacitor to a coil and waiting for the energy to be consumed via resistive losses.
The field is determined by the current. Remove the current and you remove the field. Just as you can't increase the current instantly, you can't decrease it instantly either, so the calculations need to be correct to ensure that the current has dropped significantly by the time that the projectile reaches the centre.
>>983554
Don't need to be completely exact with the calculations. The closer the projectile is to the middle position, the lower the force.
Anyone ever seen a coil assisted sling shot mechanism, or slingshot assisted coilgun as it were? So the initial movement is the slingshot
>>983530
The fuck do you need a computer model for?
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html
>>984326
To get the field gradient based on coil parameters?
>>983161
mecruy is absorbed primarily through the respiratory system in it's most harmful state, vapour. there's a reason chinese nobles would drink the stuff and not immediately die.
>>983165
>current year
>expecting this to work on a non-hobbyist unix system
haha
>>983515
rated
_____
Post
>>984294
Was thinking of a pneumatic initial stage. Though plastic barrel and projectile shape would probably make it pretty poor.
Alternatively, a spring loaded plunger.
>>984648
Pretty sure approximating as a uniform field will be perfectly fine for the purpose of accelerating a bearing through a solenoid.
>>987136
A uniform field would mean there's zero acceleration.
>>984648
>http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/solenoid.html
field is constant inside the solenoid
field is negligible outside
>>983496
Love this vid, looked for it a few weeks ago and couldn't for the life of me find it, thanks!
Anyone who seriously adheres to "it's not the volts that kill you, its the amps!" usually has no electrical experience past high school physics. I love it when people argue with me about that as though I'm not in an EE program.
>>983515
Iunderstoothatreference.jpg
>>987451
But he literally said in that video that it's not the voltage that kills you but the amps
>>987614
yes
>>983160
That is better
https://www.youtube.com/watch?v=QS4RKoRyTik
>>987653
Good design and workmanship, but I find it somewhat dull. There's nothing particularly interesting in the design and it's just using electric motors.
Now if it had a very fast cycle or use a more interesting way or coking it, like gunpowder pistons.
The version of this I'd like to try building, would accelerate a little n gauge rail car on a circular track, like a little particle accelerator. Since the projectile isn't actually leaving the barrel, it seems like it would be a lot safer.
Also I want to play with building a supercap array to charge my cell phone. To be able to walk up to a mains outlet, plug in and charge it in a moment, and then walk away and slowly charge the phone over time, that would be top kek.
>>983160
>coil gun
https://www.youtube.com/watch?v=mdZo_keUoEs
>>988495
The kickback from the coil made me think.
Won't it wear out the enamel and short out eventually?
>>987317
I mean uniform in the sense that at any given time, the magnitude and direction the field is the same at any point in the solenoid. You can still vary the field by changing the current in the solenoid. i.e. within the coil, the field is not a function of position, only time.
>>987317
>>988709
Actually now that I think about it the projectile will be moving along the field lines so there won't be any acceleration from time variance anyway. Pretty sure all of the acceleration comes from the fact that as the projectile approaches the coil it
A) gets magnetized
and
B) increases the inductance of the coil
My coilgun idea.
>copper discs (penny sized)
>rotated to several thousand rpm
>shot with small liquid nitrogen tank for superconductivity
>hydraulic assisted firing mechanism
>>983195
You monster.
>>983160
I want one of these, except with an extended barrel/coil, higher power, slightly larger bullets, a scope, and a bipod. Time to fuck some deer up with a fallout gauss rifle.
>>983515
Electric Love
For all the math and physics we had in uni, wish they taught us how to actually apply it to make a model.
Maybe I should just forego any attempts at calculations and just build it solely on loose approximations and guesswork?
Current plan is 12x40mm projectile, 6 layers of 1.4mm wire, 8 stages, 25-50V source (probably lipo), MOSFETs with drivers for switching. Thoughts?
