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Hey all

Just wondering, has anyone here any experience of sticking LEDs into parts of models that have been magnetised so that they can be removed/swapped around but can still be lit - for example an LED in a gun that is magnetised to a vehicle and thus can be removed or LEDs in a figure that is magnetised at the feet (or whatever joins to the base/vehicle) and can be removed from it's base or vehicle?

I'm thinking that sticking tinned wire ends between the magnets (perhaps secured with, or soldered to, copper tape) would create a contact point in the wires that you can simply pull apart and is forced together by the magnets, but I'm also thinking that with the space being quite small on some parts it would be difficult to keep the pos/neg wires apart?

The only other way I can think of making a connection is using micro JST connectors, but I'd have a wire dangling and it'd look ugly, not to mention a bit fiddly to pull apart when changing out weapons and bits...

Thanks in advance for any other ideas on this.

connect your wires to the magnets?

Do Neodymium magnets conduct electricity enough for that to work?

Rob Lee wrote:
Do Neodymium magnets conduct electricity enough for that to work?

Quality ones do. Quite well even. Magnetic Contacts are pretty old school everywhere else in the electrical world.

Ah well that probably solves that problem then. I've got some magnets, coin cell batteries, and SMD LEDs I can have a play with.

My next problem would be routing wires through the legs of a figure to magnets in the feet. Might just have to glue the figure to a base and run the wires down the back or side of the legs and down into the underside of the base instead of through the legs, perhaps have the figure powered separately.

You could try this stuff

https://www.amazon.co.uk/Conductive-silver-paint-conductive-varnish/dp/B00PSKQZ60/

I know someone on the Warhammer Underworlds FB Group used it for lighting up the Nighthaunt from there.

Rik

Thank you gentlemen.

@Rik - I might give that conductive paint a go one day, but I think at nearly £10 a pop it's a bit of an expense just for one model at the moment, I'm on a tight budget so trying to keep the build cost down...

Because the model being lit is a Necron model I can get away with routing wires down limbs where necessary and just paint them black or silver to hide them, or even paint them up as a detail part, they're "just extra wires on a robot".

I'm yet to receive the model (or the LEDs I ordered) though but I think I will discard the idea of lighting the 2 smaller guns on the model (the model is the command barge). I had a plan of removing the rounded barrel parts and replacing them with clear green rod and lighting the rods, but I think keeping the pos and neg wires separate in the smaller guns, because obviously (I assume) you can't connect both wires to the same magnet, is going to be a problem due to lack of space...

I can still do that to the two big guns for the Annihilation Barge option though, I think...


Anyhow, today I had a go with some 2mm x 1mm neodymium N52 magnets (a bunch in a stack about 3/4 an inch long), a 2mm warm white LED (think it was resistored for 9v) and a CR2032 battery in a holder...

...and wow, the LED did indeed light up when the pos wires were connected with magnets making the join (I connected the neg wires directly, no magnets involved).

Who knew?! (apparently everyone but me!)

I wish I had known that when I built an Imperial Knight last year, I could have stuck LEDs in the cannons, and used an arduino board to give them some kind of pattern to represent the gun being fired (for example I could have put 6 LEDs in the the gatling gun, one in each barrel, and used arduino code to light each in turn rapidly so it looks like the gun is firing). Too late now though!

Rob Lee wrote:
Do Neodymium magnets conduct electricity enough for that to work?

The plating will most certainly conduct. Getting solder to stick to the nickel plating is going to be tricky, though - and too much heat on the magnet will kill it, too.
Magnets will pass an electric current even without touching (current passes along a magnetic field between conductors). It's part of the whole electromagnetism thing.

Might be easier to use thin clear rod in the weapon and mount the LED on the model (so that when you line them up, the rod acts as a "light tube" for the led?)

Problem with magnets is that you would need 4 magnets in each arm. two on the torso side and two on the arm side so that you can run a positive and negative.

another option as suggested is conductive paints but making sure both contacts touch properly and wont wear out is going to be tough.

another option might be lining up fiber optic bales though making sure you dont light bleed is going to be interesting.

Probably the easiest way is to mount the led in the weapon and use a pin/socket arrangement between it and the vehicle/mounting. You would have to only ensure that you put the pins the right way around (because LEDs are polarised, and only work "one way". They are in essence, a one way gate).