Monday, 15 October 2007

Rare-earth magnet and Carnifax conversion

At long last I've finally gotten the time to do the article on rare- earth magnets and converting a plastic Carnifex using them. (As well as rare-earth magnets in general for a variety of model conversions.) The pics for this article are all located in my Photobucket web page if you want to look at all of them at once…

What, Where, and Why?

I use the following sized 'rare-earth' magnets on a regular basis.

  • NdFeB Disc Magnet, 3/8 in. x 1/8 in.
  • NdFeB Disc Magnet, 1/8in. x 1/16 in.
  • NdFeB Disc Magnet, 3/16 in. x 1/16 in.

What all have I converted with rare-earth magnets? Lets see…

I've converted Dreadnoughts with standard plastic arms and heavy resin Forgeworld arms, I've used them with Armorcast resin critters,

I've made magnetic mounts on GW Rhinos to convert them into Preds at will, I've made magnetic mounts on weapons hard points to swap out weapons on Predators, Whirlwinds, and Razorbacks.

I've used them on a Forgeworld Hydra gun emplacement to make it extremely simply to disassemble, store, and transport and otherwise expensive and fragile model.

I've also converted IG heavy weapons crews so that I could swap out tri-pod mounted weapons at will. I've done individual marine command figures with magnet shoulder mounts so they can choose between various weapons options without needing to buy, build, and paint umpteen different models.

I've used them to make the aforementioned magnetic Carnifex conversions, as well as on Hive Tyrants - including one with detachable wings for that 'Death From Above!' action.

In short, I've VASTLY INCREASED the flexibility of my army lists for a modest investment of time and minimal amounts of extra money. (Especially when compared to buying, building, and painting additional minis and vehicles needed to achieve those same 'options' in my army list.)

Where does one get 'Rare Earth' magnets?

Where do I typically get my 'rare-earth' magnets? In the past my friends and I have purchased from the 'Wonder Magnet' web site below. Unfortunately when I looked, WM didn't have either of the two smaller sized magnets listed on their site in the inventory any more. In the past we've always gotten excellent service from Wonder Magnet, so if you're interested, you could email them and inquire about the possibility of more of those sizes being produced. (I think they produce their own, rather than resell - though I'm not 100% certain of that.)

Your next choice would be Amazing Magnets. They have an excellent selection with prices listed. There are also other specialty sites if you look around the web such as or ttp:// (These folks have a nice magnetic FAQ on their site)

Where not to buy.

While there are some great places to buy magnets, there are some pretty crappy places as well. For example, 100 of the 3/16 in x 1/8 in magnets from Amazing Magnets would run you about $20 including shipping, etc. Buying the same from a retail outlet like Radio Shack will run you about $80 plus tax. (Yikes - Holy Wallet Rape!)

I also don't recommend Ebay or similar sites - 1st of all, the reseller wants to make a profit which means you, the buyer, pays more - and 2nd, you have no idea of the quality of the magnets and virtually no recourse if they turn out to be weak or poorly made.

Personally, I'd advise sticking with a reputable business, you're far more likely to get better products and much better prices.

How does one use magnets for conversions?

Rare-earth magnets are amazingly strong for their size, which makes them ideal for use in conversions of metal and plastic minis. They allow not only quick swaps of various parts, but are strong enough that limbs can be posed in 'normal' positions and don't droop down to the ground from their own weight. (Nothing looks goofier than a Dreadnought in the midst of battle with its weapons pointed at its own feet.)

As an added bonus, if one is concerned that a single magnet on each side isn't strong enough to hold a part in the desired position, one can 'stack' magnets several deep in a shoulder or other area to increase the amount of pull generated for a stronger and more stable mounting point.

As I mentioned before, I've used magnets for even heavy jobs like holding heavy resin model parts in place, and the results have been superb.


  1. Did I mention that rare-earth magnets are amazingly strong, and that if you stack them together they have even greater force. A good rare-earth magnet the size of your thumb can potentially lift 20 to 40 pounds - or more! Needless to say, getting your fingers smashed between groups of these things that rapidly slam together is going to be painful. Use caution.
  2. Check your polarity before gluing! Magnets not only attract, but also repel if you attempt to bring like poles together. Nothing can doom a magnet conversion project faster than not paying attention to the polarity of your magnets until after the epoxy or super glue is dry. Always check the polarity (and recheck if you're not certain) before applying the glue to the magnets. I tend to use a small felt tip marker to mark the side of the magnet that should be facing outward when I glue it in place.

NB: I find that if I'm going to do multiples of the same type of conversion (like IG heavy weapons teams or multiple Carnifex) that it is extremely helpful to do a 'master' version first and then make sure that the rest follow the exact same 'magnetic pattern'. This means that when I'm done, I can swap parts between ANY model of a specific type and not just one particular model. A little extra work in the beginning saves a lot of time and effort later on.


So, how does one convert a Carnifex to allow it the whole range of biomorph and weapons options? Fairly easily. Regardless of whether you're an 'assemble then paint', or a 'paint then assemble' type of model builder, you'll definitely want to add your magnets to the necessary places on the model BEFORE you fully assemble the model. And read ALL the directions before you begin.

As for tools, I'd recommend the following:

  • Magnets - for this project we'll be using 1/8in. x 1/16 in and 3/16 in. x 1/16 in magnets.
  • Clippers - for removing your parts from the sprue
  • Sharp hobby knife - for trimming up the parts and removing burrs, etc
  • Small flat file.
  • Small electric hand drill, or a variable speed dremel tool with drill or boring bits.
  • Epoxy or Super Glue - I tend to favor using epoxy for greater strength with the larger magnets 2 Part resin epoxy putty or 'Green Stuff' - used for strengthening certain parts and to disguise where magnets have been put into certain limbs or parts
  • Felt tip pen - for marking magnets and where the center of drill holes should be located
  • Wooden rod (like the end of a paint brush handle) - for adjusting magnets
  • Metal rod (or thin metal part like the tang / handle of a metal flat file) - for inserting magnets

NB: After examining the new plastic Carnifex model, I discovered that the top most spine on the tail section is made in such a way that it forces the upper body of the Carnifex to hunch over so that the 'standard' model is always looking at the ground right in front of itself like "Oh Damn! I just lost a contact lens - no body move until I find it again!"

Needless to say I found that particularly unappealing, so my first recommendation is to file down that spine (or alternately remove it all together) so that the Carnifex can be modeled standing in a reasonably upright position.

The best way I've found to start on the Carnifex is to begin with the magnets in the torso itself. Since we're using 1/8 in and 3/16 in diameter magnets, it's fairly easy (in the US) to find small drill bits that are a perfect match diameter wise. That said, dremel bits of the correct diameter work just as well. I used the larger 3/16 magnets for the 'in torso' arm mounts, and the smaller 1/8 magnets for holding the heads and carapace pieces in place.

Before gluing the torso together - I drilled holes just large enough to snuggly fit the 3/16 in. magnets in the center of each of the arm placement sockets on the main torso.

Pick one side of the torso and carefully glue in your magnets so that they sit reasonably flush with the bottom of the socket.

I used epoxy from the back side / inside of the torso to firmly anchor mine in place.

Make sure that your magnets are both aligned with the same polarity facing out i.e. either both North, or both South facing out. (This is where that felt tip pen comes in handy).

TIP: Always allow your glue to dry completely before test fitting other parts with magnets. It's way to easy to pull out a magnet you've just glued in, and it's a mess to fix and way to easy to accidentally reverse the magnet with unfortunate results later.

Once the glue is dry on your first torso half, make sure your magnets fit in their holes on the second torso half and that they're aligned so that they don't repulse the magnets in the first half. (You can stick the magnets on the back side of the magnets in the first torso half, mark the sides sticking out, and then glue them in the second half with the marked sides sticking out the socket holes.)

After the glue is dry, you can use some putty on the back / inside of the torso where the magnets are for extra support if desired (I did) and then glue the torso halves together and allow it to dry.

(If you look closely, you can still faintly see the black dots from the marker on the magnets.)

Next up is the magnet mounts for the head and upper carapace.

Since neither of these plastic parts weights very much, the smaller 1/8 in. magnets work fine for our task. Because of the torso's design, it ends up that we'll be mounting them both right where the two torso halves glue together on the front. Due to this, it's far easier to mount the magnets after the torso is glued together.

You can eye-ball the center of the socket for the head and mark it with the felt tip. On the carapace take the actual carapace piece and mark on the back side where you want to put in the magnet. Then measure down from the apex of the inside of the carapace to find your distance. (Mine was about 5/16 in or 4 mm down from the top.) Now measure the same distance down from the apex on the front surface of the torso and mark where you need to drill.

TIP: How to drill without going to deep or otherwise damaging thin plastic parts. The easiest way to control the depth is to put a depth gauge of sorts on your drill bit. Place the magnet next to your drill bit so you can gauge the distance that the drill bit has to go to create a sufficiently deep hole without going to far, and then wrap some masking or duct tape around the drill bit above that point.

That way, when you drill into your parts, once you get to the tape you know you've gone in deep enough to accommodate the magnet without going in to far.

The second thing to remember is 'start small and work your way up'. I recommend on small parts that people start with a very small bit and drill an initial 'pilot hole' if you're going to be putting in a magnet that is nearly as wide as the surface it's being mounted in.

You can easily do the initial hole with a pin-vise / hand drill if needed, and then work up to progressively larger bits until the desired size hole is created.

It takes far less time to do something right the first time then it does to repair something that was botched. By using progressively larger bits and light pressure, it's easy to get a clean smooth opening in short order without trashing expensive model parts.

Using a 1/8 inch drill bit, carefully drill out the holes in your marked locations on the torso. If you need to, drill a test hole in a piece of sprue or wood and test the snugness of the fit with one of your 1/8 in. magnets. It should be snug enough that the magnet won't simply be loose and fall out. Once that's done, you're ready to glue in your magnets on the front of the torso.

TIP: How to glue in a magnet when you can't get to the back / interior of a part. If you have to glue in a magnet and the area behind the magnet hole is hollow, it can be tricky not to push the magnet in to far and have it end up rolling around the inside of the model rather than glued in place.

I found a relatively easy method to deal with this.

Place the magnet on the end of a short metal rod (the narrow tang on a metal file also works well for this) with the 'outward facing' side against the metal rod / object. (You are using that felt tip marker to prevent mistakes, aren't you?)

Apply a reasonable amount of glue (I tend to use liquid super glue for this rather than epoxy since the magnets are small and won't be holding a lot of weight) around the edges of the opening where the magnet goes, and then insert the magnet to the correct depth using the metal tool. (Using the metal tool helps prevent pushing the magnet in to far.)

Once you have the magnet flush with the front surface, you'll need to drag or pull the metal object sideways across the surface (rather than straight up) so as not to pull the magnet out of the hole.

If the magnet shifts while you're removing the metal tool, use your wooden rod to gently reseat the magnet so it's flush with the surface of the model or otherwise sitting correctly in the hole.

Using the above method, glue your 1/8 inch magnets into the front of the Torso and allow the glue to dry.

While you're waiting for the glue to dry, you can cut out the rest of your head and carapace pieces, clean up the sprue marks, and glue the heads together as desired. (If you have a real problem with pushing the magnets in to far, you can always fill the hollow neck parts of the heads with putty before you glue them together, but I didn't find it necessary when I did mine.)

Since you already have the measurement from the first carapace piece, you can measure and drill the others.

With the heads, I simply eye-balled the center of the back of the neck pieces, and then marked and drilled them with the 1/8 in. bit.

Now that you have your 'master' torso done, you can zip through aligning and gluing in magnets on your various carapace and head pieces. (Remember - mark and check your magnet field alignment twice, only glue once.)

Next up is putting magnets in the various limbs. For the larger limbs I used the 3/16 in. magnets just like those in the torso itself, for the smaller limbs or where two limbs join (like the Venom cannon or Barbed Strangler arms) I used the smaller 1/8 in magnets.

Normally, trying to drill holes in the round ball ends of the limbs (without the bits slipping or otherwise going in at the wrong angle) can be a major pain in the butt. This is where the flat file comes in.

Since we've flattened out the bottom of the sockets on the torso by gluing our magnets in, filing the end of the limbs a bit to create a flat surface to drill into and place the magnet isn't a problem at all.

Try to file the flat spots on the ends of the limbs so that the limbs will stick out in a reasonable angle (i.e. don't file the end of the elbow and then be surprised when the arm sticks straight sideways), but it doesn't have to be 'exact' since we're using strong magnets. Using the drilling tip above, and marking your magnets, glue your magnets for your limbs into their respective holes.

NB: In some cases there was simply not sufficient room to drill a hole for the larger 3/16 magnets on the ends of some of the larger arms that I wanted the bigger magnets on. In those cases I simply filed off 1/16 of an inch (width of the magnet) or so from the end of the arm, carefully glued on the magnet in the center of the flat area, and then covered the joins with epoxy putty / green stuff that I smoothed out to match the rest of the limb.

Once you have your magnets all mounted, you're ready to use your epoxy putty or green stuff to touch up any areas that still need work. Then you're ready to assemble the body and paint, or to paint your parts and then glue the legs, tail, and torso together. In either case, attach your magnetic parts - and Bob's your uncle.

When I finished the first torso, I proceeded to do the magnets on the heads, carapace, and limbs for all 3 models. After that, it was a simple matter to 'reverse engineer' the remaining two torsos by making sure that the arms, heads, etc worked on each torso. Having done that, I can now mix and match limbs, etc with any of the 3 models without worrying about magnets repelling each other. (That and I can now field the misunderstood and wrongly feared '5 headed Carnifex' - I keep telling opponents "Don't worry about him, he's 'armless.")

All in all, I've been very pleased with the results of my Carnifex conversions, and I've garnered some nice compliments from other gamers along the way. But you can judge for yourself. Additionally it didn't take all that long to do the conversions, it's just taken me forever (as you can tell from the pictures) to actually finish painting up the 3rd Carnifex. Doh!

This same sort of thing can easily be done with smaller models like Marine Vet Sgt. and Commander figures where it would be nice to have a variety of options in wargear / points costs and still be WYSIWYG using the 1/8 inch magnets. (And for the record, I hand drilled all the holes on these bits with one of those *supposedly worthless* variable speed Dremel tools.)

Hopefully that covers the vast majority of questions. If you have any additional questions, or you hire Johnny Cochran as your lawyer - I'LL KILL YOU!!1! Just kidding, if you do have any additional questions, post them and I'll try to answer them as needed.

Hope that helps,


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