Written by Graham Sheckels, aka BoB_Lorgar
What is a rotary tool?
In this treatise, I'm going to discuss what uses a rotary tool can be put to, and what accessories you may find necessary/helpful as you go about your modeling and converting. The most popular brand of rotary tool is made by the Dremel company, and so many people mistakenly refer to any rotary tool as a Dremel. Unless otherwise stated, you can assume I'm talking about Dremel brand parts and accessories.
So what will I need?
Well, first off, you'll have to actually get yourself a rotary tool. As I stated, the most popular model is made by Dremel. Their current model is #395. Other brands include the Sears Craftsman Variable Speed Rotary Tool #00961084000 (which, I believe, is the Dremel #395 marketed under the Sears name), and the Black and Decker RTX High Performance Rotary Tool. Another competitor is Proxxon. These will all run you around $30.00, bare-bones. All kinds of starter kits are available which will come with various additional accessories. These tools' common feature is that they are all variable speed, which is rather important.
What should I avoid?
Cheap knock-offs - they do exist out there. Myself, I would recommend avoiding them. You usually get what you pay for, and in my opinion when you're buying power tools (where safety/quality of manufacture are always an issue), you really ought to avoid companies you've never heard of. Sure you may save $20, but is it worth it if the thing breaks while you're using, and you get seriously injured as a result?
Different bits you may use in your rotary tool are meant to be used at different rpm's. Using a cutting disc at the wrong speed can not only ruin it (and perhaps the conversion you're working on), but can also pose a significant health hazard. Being able to adjust the speed is critical to safely getting the most out of your rotary tool. So I really would make sure you buy a rotary tool which has a variable speed control. But what if you have an older model rotary tool which isn't a variable speed model, or you bought one of those really cheap imitations? Well, Dremel sells their Foot Speed Control #221, which consists of a foot pedal you can attach to your older model rotary tool and allows you to adjust the speed by adjusting the amount of electricity which flows into the rotary tool. You should note that if you're just starting out, it'll be cheaper in the long run to buy a newer rotary tool which has a built in speed control.
There may be some debate on this, but I'd recommend against any of the cordless rotary tools available. Their primary feature (not having to plug into the wall) probably won't be a factor while you're sitting at your hobby desk, and generally corded models will be able to supply more power.
What accessories may be useful to me?
The most important accessory you can buy is a pair of safety goggles! Like any power saw or drill, this thing can send tiny metal bits flying while you're using it. Serious injury (up to and including blindness) could result from them striking you in the eye. You should ALWAYS wear safety goggles while operating this thing.
For a Dremel ® tool, I highly recommend their three foot long Flex-Shaft Attachment, #225. This is, as the name implies, a flexible shaft that attaches to the Dremel ® tool. What it allows you to do is use the rotary tool much as you would use a pencil. The basic model is rather awkward to grip and use on small parts (such as your miniatures), and the Flex-Shaft is fantastic at allowing you to control where the bit is going and what it is doing. They retail for about $25, and in my opinion are an almost mandatory accessory.
I also recommend a Dremel Keyless Chuck #4486. There are several different shaft sizes for the bits you may want to use. Unfortunately, your basic model rotary tool will only be able to grip a small range of them. The part that grips the bits is called a collet, and it will only come with a single collet, which can only accept a small range of shaft sizes. Of course, you can always buy other collets which will take bits with smaller or larger shafts. This can be a pain in the neck, though, if you're constantly switching from your tiny drill bit to your big cutting wheel to your medium sized engraving bit, because you have to figure out which is the right sized collet and then install it onto your rotary tool. The easiest way around this is to buy the Keyless Chuck, which can hold any and all sized shafts, and allows you to swap bits in seconds. For $10 or so, in my opinion it's a great time saver.
Lastly, I would get from Dremel their D-Vise #2214. The D-Vise, is as it sounds, a vise, and it retails for about $20. It has some nice features to it, such as the ability to rotate and swivel to a wide range of positions (and yet still lock firmly in place). It is also mountable on your hobby desk - of course, you'll have to drill holes in the desk, but then you have this nice rotary tool, which can use drill bits... My favorite feature is the rubber padding on the jaws. I have found that they give you a very secure grip on your miniature, and yet the rubber prevents the vise from crushing or otherwise harming your Terminator Captain. But aside from these features, I recommend having a vise of some kind, for two reasons. First off is safety. It should be obvious to you that if the cutting disks can chop the arm off of that Bloodthirster model, they are also quite capable of doing nasty things to the fingers you're using to hold the Bloodthirster's arm. A vise is really a good idea for keeping your fingers intact. If you miss with the cutting disk (or drill bit, or whatever), you're likely to hit open air, or at worst the vise itself, instead of putting that drill bit through all the way through your palm or having the cutting disk go all the way to the bone before you can turn it off. On a related note, when you're cutting or drilling into a miniature, it is possible for the heat generated to be so great that the metal near the drill bit or cutting wheel to melt. You'll quickly notice that that's also hot enough to burn your fingers if you happen to be holding onto the metal part.
The second reason for a vise is similar to the first. If you try and do any fine detail work with your rotary tool, you may soon realize that it's difficult (if not impossible) to hold that Space Marine steady while you try and remove his chest eagle. And it's really annoying to accidentally take his face off instead... With a vise you can be assured that the miniature itself isn't going to be going anywhere, and all you have to concentrate on is the rotary tool itself.
So now what do I do with this thing?
So now you've got yourself a rotary tool, and you're eager to go using it. Basically, what you can do with it is decided by what bits you use in it.
Detail removal - Let's say you bought a nice new Inquisitor Artemis figure, and you're keen to convert that wussy Deathwatch Marine into a glorious Champion of Chaos. Well, it just won't do to leave that Imperial Eagle on the chestplate - after all, he hardly could be said to be a loyal subject of the Emperor! You could take out your file and/or hobby knife and cut and file the Eagle away, but your rotary tool is a much better tool for the job, able to achieve the same results in seconds as opposed to hours. I recommend the Engraving Bits, sizes 100, 105, 106, and 107. These all are essentially a spherical cutting bit on a long shaft. If you touch them to the metal detail you want to remove, they're able to quickly eat it away. Of course, the smaller the bit, the slower it will go, but that can be a good thing as it gives you more control over the process. Note that you can also use these bits for things like removing the head from a Chaplain so you can replace it with a nice unhelmeted head (or whatever). You should note, though, that the original head won't be saved - it's going to end up as a billion little metal shavings.
Pinning - Instead of using a Pin Vise to drill holes for pinning, many people use their Dremel instead. Myself, I rarely find that my Pin Vise is unable to do the job, but if you really must save 30 seconds, your rotary tool is quite able to drill holes in your miniatures. With the Keyless Chuck mentioned above, almost any size drill bit could be used. Dremel sells a variety of sizes, but I believe any drill bit you come across should be adequate for the task.
Cutting - Many people also use their rotary tool for cutting the arm off a Bloodthirster, chopping a scout's legs off so they can be repositioned, or whatever. For this, you can use Dremel's Reinforced Cut-Off Wheels,#426. Myself, I normally use a Jeweler's Saw for these types of conversion, so I can't really offer much advice, except to say that I know other people swear by their Cut-Off Wheels. Remember to always be safe while using them, though - that includes wearing safety goggles and holding the miniature in a vise instead of with your fingers.
Removing Flash/Mould Lines - Again, I haven't done this myself, but I have heard of rotary tool being used for this. Basically, I believe they use Dremel's Stainless Steel Brushes, #530, 531, and 532. If you run these brushes over small mould lines, I believe they should easily remove them, without that pesky filing or scraping with a modeling knife. With plastic parts, use part #535, brass brush, use a light touch and you can quickly remove mould lines without doing any detail removal.
Other uses - Dremel makes at least a hundred other bits for use in their tool, from routers to bathroom tile cutters to polishing disks. Who knows, you may figure out a way to use them in your converting work. Or even just use them around the house. In any case, you can visit http://www.dremel.com for lots of other uses for your rotary tool, and for other accessories than are mentioned here.
One last note - when you buy your rotary tool, it's going to come with an instruction book. I highly recommend reading through it - not only will it tell you how to get the most out of your rotary tool, but it will give you all the information you need to operate it safely. Please folks, let's keep the hospital visits to a minimum.
User:Tierlieb: If you got the chance, get a Proxxon. Why? You get a set of interchangeable chucks and a quick-change feature. This way you can use both Dremel and Proxxon tools and most specialized jeweller's tools. Otherwise, Dremel and Proxxon seem to be on equal footing, features one model offers, the the other company usually introduces in their next model, too. I've been using my Proxxon for about 6 years (as of 2009) on everything from tin to hardened steel, no wear and tear visible. Proxxon also offers an industrial strength variant with a die-cast housing, but I never had the need for it.