-MAGNETS-

Magnets as we all know are fun. When they serve another purpose, even better! So other than sticking things together (opposite polarities attract, North sticks to South), they can be used as pivot points, catches, for turrets, accessories, swaps (heads & weapons etc), help transport/store models, pick-up tools, as well as many other uses.

However, magnets are not always fun and stronger ones can cause real problems, like when models go flying through the air and collide forcefully sending bits everywhere. Or a misplaced dot of superglue and then suddenly the magnet comes out of your clutches and sticks where you don't want it.

There's also 'Humping-syndrome', where one model's base is attracted to another model's base and if not careful, will mount the second base, thus damaging it. Having magnets placed near the edge of a base doesn't help. If possible, place magnets in the centre.

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These figures have metal between their feet. You should remove this so that the magnets can be more centred. The magnets used above are quite strong. They're not too bad when bases touch each other (hand to hand combat), however it's as you pick them up, suddenly the power of magnetism takes effect! I prefer weaker magnets instead. Which way round (polarity) you stick them in is up to you, but if you're playing on a funky magnetic board, you may find that your models will not stay down. And once you've decided which way - stick to it. I keep a 'blank' base with just a magnet in it for referral. When transporting, you might want to put a metal strip in your case to stick the models too (also helps avoid 'Humping-syndrome'). A steel ruler might do the trick, it's fairly light, cheap and still handy to have as a ruler!

Cover magnets over if possible. Paint can chip of them quite easily particularly if the magnet is constantly having things being stuck to it and removed. Use the right kind/size magnet, for the right occasion. If you've got the space, use a cabinet magnet (big). Save your smaller/stronger ones for times when you need them. Sometimes you'll need 2 magnets (say, to hold an arm to a torso), but sometimes you can get away with just one (head swaps - where the neck has the magnet and the heads have a pin in them). The heads will also be able to rotate afterwards! You can also transfer magnetism like this. EG carry magnetism down the arm, to the hand for weapon swaps. Note magnetism strength decreases the further you go. Use a wire and make sure it's in constant contact with the magnet.

Where To Get Them

Art & craft shops - Fridge style, other types, expensive.

Stationary Shop - Sheets. Fridge style, labels etc.

DIY Store - cabinet catches. Usually a couple of sizes and depending how big the catch is, you might get two magnets inside. They're normally rectangular in shape and stronger than a fridge magnet. Use clippers and hack them out. Bonus - a couple of metal plates and the plastic casing.

Online - Lots of places with deals, so shop around.

www.e-magnetsuk.com

www.powermagnetstore.com

www.first4magnets.com

Magnetic Paint

www.happypuzzle.co.uk

www.magneticpaintshop.co.uk

Rating Magnetic Strength

There's a word used within the industry to measure/rate the strength of magnets - GAUSS. Gauss however only indicates the core strength of the magnet. It doesn't take into account the magnetic field on the surface of the magnet. Not just that, but the geometry, size/shape, the materials it's made from, and temperature also affect the overall strength. To make it more confusing, Gauss isn't simply a number.

The instrument used to measure gauss readings measures lines of magnetic flux at a specific point on the magnet. It's only an indication and not a true measure of the strength or penetration depth of a magnet.

As a guide, you can work out 'proper' gauss strength by multiplying the external gauss rating by 3.9 (Or if you know the internal and looking for the external, then divide).

EG an external rating of say 700 might also be known to have a 2730 internal gauss rating.

Another quick method to measure magnetic strength is to use a bunch of paperclips (same size), and count how many the magnet can pick up! If you have lots of various magnets, perhaps enter your data into a table for future reference.

Types Of Magnets

Bipolar - North and South polarities both on one side. Usually thin and flexible.

Unipolar - North and South on opposite sides of the magnet. Stronger as they exploit the laws of physics.

Depth of magnetic penetration (inches)

 Bipolar  Unipolar

Bioflex                  0.60

Magnelyfe             0.10

Nikken                  0.70

Trufit                    1.25

Magnet Relief          1.90

BMI                        1.50

Tectonic                  4.25

 

Electro Magnets

The strength of these depends upon the amount of coils (solenoids) and current passing through them. Also the supply of power needs to meet the needs of the circuit. Due to this reliability on power supply, they are not often used within machines and tools. The only advantage of using electro magnets is to be able to control the applied field levels created.

Magnetic Fields

Tesla is the measure of intensity of a magnetic field.

1 Tesla = 1 Weber (per second) = electromotive force of 1 volt. Another way, 1 tesla must exert a force of 1 Newton on a length of wire 1 meter long carrying 1 ampere of current. A Newton is the force used to accelerate 1 kg weight at 1 meter per second squared.

The Earth = 1/30,000th tesla.
Jupiter = 1/3,000th tesla. 10x the Earth.
A loudspeaker = 1 - 2.4 tesla.
Levitate a frog = 17 tesla.
Superconductors = 20 tesla.
Strongest continuous magnetic field generated = 45 tesla.
Strongest pulsed, non-destructive field = 100 tesla.
Explosively pumped flux compression generator (short life) = 2,800 tesla.

What Metals Are Magnetic?

Just a quick guide. Not extensive.

In terms for modelling use, keep it simple. Iron is the best choice for magnets to stick to and is easily available.

'Ferrous' metals contain iron and 'Non-ferrous' metals do not and are more resistant to corrosion.

Ferrous (Magnetic) - Iron, Nickel, Cobalt,

Non-Ferrous (Non magnetic) - Aluminium, Copper, Tin, Lead, Zinc, Brass, Silver

Alloys - If it contains ferrous metals then a magnet could possibly stick to it. Steel is iron and carbon. Alnico is made from iron, nickel, cobalt and aluminium. 'Permalloy' is iron and nickel.

BTW - Iron will rust if it's left exposed (oxidation). Rust also spreads and can spread under paintwork. Steel if not careful will also rust as it contains iron. Stainless steel is a bit different (I'll add more info at some point).

Stuff Magnets Can Stick To

Some putty comes with steel in it, although not magnetic itself, magnets will stick to it. It's heavier than normal putty, so would be good for bases. Iron filings are also good. Getting them however can be tricky. An alternative to iron filings is steel wool. Chopping it up so that it's resembles more like the iron filings can be time consuming.

As mentioned before, there's magnetic paint. Although with time the magnetism may decrease and a recoating of paint is required. You could mix magnetic particles into some paint; however you may get a textured finish (likewise with iron filings).

Dusty's Magnet Collection

Here's a bunch of magnets I use:

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The sheet is not very strong as a magnet. It's a thick as say card and can be cut with scissors/knife. The green block is a tool (explain later). The strip below it, going left to right: strong good magnets, fridge style, and catches for cabinets. The strips below that are more fridge style magnets. They're stuck on a magnet strip from the door of a fridge (what holds the door shut - but don't go cutting them out of your 'current' fridge, or else the door won't stay shut. Find an old 'unused' one).

These (below) are the cabinet catches. Just use clippers and snip them out.

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These (below) are fridge magnets. You could just simply paint over them with your own designs etc.

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These (below) are again fridge magnets (one with a clip). These were obtained from arts & crafts stores. I usually use these for bases.
The slim rectangular one on the far left is probably the worst type, although it seems to only have magnetism on one side (Bipolar).

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These (below) are my stronger ones (purchased online).

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The far left ones are the strongest of them all (about 1mm thick x 10mm diameter). Again you could get these from a craft store, however usually a bit more expensive. When I ordered, I got a bunch of different styles 'just in case', but after sticking in loads, I've realised that the ones on the far left and far right are what you'll need most. The ones in between I'm now trying to get rid of. At the time, the stack of 3 are the ones I had to grind down to fit inside the feet of an Eldar War-Walker.

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This little block claims to be a magnetizer/demagnetizer tool. It didn't really come with any useful instructions. So perhaps I'm using it wrong. It doesn't seem to 'Demagnetize' at all. I'm guessing you pass the object through the hole depending upon your requirements. It does however 'magnetize' objects. Not too expensive (about £5 - Maplins)

Cutting/Grinding

To cut a magnet is hard without specialist equipment. It is possible to grind them down using a 'dremel'. Secure the magnet in a vice and WEAR goggles. It's a slow process and becomes harder as the magnet gets smaller. Also the sparks caused from grinding are magnetic. They collect and get in the way (and probably get inside the dremel).They can also be difficult to remove from the magnet itself, making it a messy job gluing them into place. Best way is to use compressed air and blow it off. Alternatively you could go mental with a brush and try to whisk it off or use tissues to wipe n' grab the particles.

These are the tips I commonly use.

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I wouldn't recommend the far right (dark green) tip.
It's there to help steer you away, they're softer and slightly flexible.

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Getting Them In There

Usually assemble parts, then drill, then stick it in making sure you've decided on the polarity. If you can get another magnet on the opposite side, you can use it to pull the magnet to be stuck into the hole (it's a bit of hassle and not very practical really). Alternatively (what's better) 'pit' the hole so that when the magnet goes in, the glue doesn't seep out the sides so much. Use only a tiny amount of glue just to begin with, to keep it in place. Then add more to secure it if need be or use putty to fill any gaps and cover the magnet over if required. Last thing you want is for the magnet to pop out of it's hole at some later date (Ever heard a rattly tank?).

The Levitation Myth

This is a very complicated subject, and many scientists etc have spent years studying it. The gist of it is; it's about getting the object to be levitated stabilized. One method uses electronics to help stabilize the magnets.

Another involves 'superconductors' (what everyone is thinking about in terms of floating levitation). That's when the material is cooled with liquid nitrogen/helium). This makes it have no electrical resistance and also external magnetic fields cannot penetrate it. Trains use this as well as theme parks and its future potential is huge. But sadly it's something that neither you nor I could probably do with the typical bits available and limited funds. It might even be something that is meant to be done in a laboratory under controlled conditions. However as time progresses and technology becomes more available, who knows!

Hope you found this article interesting and useful.

GOOD LUCK and have fun.