Building a railgun

Plasma, Sat Jan 14 2017, 04:05AM

I'm constructing a railing.

The power supply is a 15kv Nst, that goes throught a capacitive voltage divider, after the bridge rectifier it's around 9kv.
The capacitor bank has 12 microwave capacitors, 4 in series, with 3 parallel.

The rails are kept short and replaced with a permanent magnetic under the plastic drum.

The pellet moves around 1-5mm per arc.


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Re: Building a railgun
klugesmith, Sun Jan 15 2017, 04:12PM

Welcome back, Andrew. It's good to see you moving from ideas to real experiments with measured results.

Your picture shows a primitive electromagnetic motor, not a railgun (or railing, at least none obvious).
That's assuming a horizontal electric current in projectile, perhaps connected to fixed electrodes by sparks.

If there's a vertical magnetic field from your permanent magnet, projectile will be forced sideways.
I bet you can improve the outcome by making a better magnetic field. e.g. pole pieces, magnets on both top and bottom, permeable yoke connecting the far ends of magnets, etc.

How about the frame and ring-shaped magnets from a MWO magnetron, reassembled after you remove the electron tube and cooling fins?
Re: Building a railgun
Plasma, Sat Jan 21 2017, 01:28AM

I've added a better magnetic path and more capacitors, every arc now consistently moves the pellet.

I collect about 4 capacitor a week, one layer has 24 caps, and aiming for five layers, per sparkgap
Re: Building a railgun
Plasma, Sat Jan 21 2017, 01:32AM

Sorry for the double post having trouble posting pictures
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Re: Building a railgun
Dr. Slack, Sat Jan 21 2017, 07:47AM

mods, move to the projectiles board perhaps?
Re: Building a railgun
Kizmo, Sat Jan 21 2017, 03:41PM

Moved :)
Re: Building a railgun
Plasma, Sat Jan 28 2017, 02:32AM

Thanks Kludgesmith, it made the most improvement, see another thread.
I've finished the first layer, and plan to workout how to build the gun.
At the moment I've got a hot ionized alkali metal to pass between the electrodes, when the bank is full charged.

Don't really have much to add, it's only being 4-5 week on this project and there's heap to go throughout.
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Re: Building a railgun
Plasma, Sun Jan 29 2017, 04:00AM

In between these picture's the camera get blind, it looks like the arc goes back towards the potassium carbonate source
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Re: Building a railgun
Conundrum, Fri Feb 17 2017, 04:51AM

Nice!
How do you plan to avoid rail damage?
Also I speak for a lot of others when I say please be VERY careful.
With capacitors this big you won't survive even an indirect shock.