Talking Tools - Routers

    Routers are incredibly versatile tools in the right hands. While they're famous for creating rounded, chamfered and even fancier edges, this popularly held perspective of the humble router hides a multitude of other potential uses that they can be used for.

    Edges are just the beginning. Some of the other things include joinery, whether that's sticking planks side-by-side using "tongue and groove" or "finger" joints. Alternatively if you're doing perpendicular joinery (for furniture, boxes, cabinets, etc) you can do many famous and common joints using a router and appropriate jigs. Some include:
    • Dadoes
    • Rebates (I believe Americans call them "rabbets")
    • Box joints
    • Knuckle joints
    • Dovetail joints
    • Mortice & Tenons... just to name a few.

    Perhaps the most underrated function of a router is to cut material very smoothly. Routers can cut woods, plastics, foams, even non-ferrous metals such as brass and aluminium. However, the metallic end requires some very shallow cuts, with multiple passes to get the job done.

    When I say "cut smoothly" this can be so smooth, that you might not actually need to sand afterwards. The cuts aren't limited to breaking larger slabs/sheets into smaller pieces like you would on a table saw. A router, with a planing jig allows a wood worker to flatten/plane huge slabs of wood that simply would not fit in everyday woodworking machines. So it allows surfaces to be cut as well as edges.

    The smooth cutting capability comes from the very high speed at which these devices operate. While a circular saw can spin anywhere between 1,500-4,000 revolutions per minute (RPM), a router usually runs at 12,000-27,000 RPM.

    Having said that, routers aren't without their challenges. Often the first, is deciding which type you need....
    Image
    This is a smaller hand-held router on a fixed base.
    Image
    This is another smaller hand held router that can have both a fixed or plunge base. However this has the plunge base attached.
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    This is a substantially bigger, and more powerful "production" router with a plunge base. This model also supports both bases if you have the compatible accessories.
    The humble router is a surprisingly versatile tool. However, with high speeds, potentially loads of power, and a bit that can tear wood and flesh asunder with surprising ease, it's not something I'd say be afraid of... but definitely handle with care.

    Routers come in a variety of shapes, sizes, features, and power. It's not always clear which one will suit your needs. So let's break it down.

    Let's talk about router types...


    In Australia, the two main types of hand operated router:

    The first type is the smaller of the two, and that is the "hand-held router" or "laminate trimmer". They are called this because they almost fit in the palm of a large manly hand, and some people even operate them one-handed. They're called laminate trimmers because they're often used in lighter tasks like trimming/tidying up the rough edges left by saws when working on laminated work pieces. That doesn't mean that they're limited to that simple task. They can work well in many situations.

    If you are using the router on the edge of a work piece, or just working on narrower pieces of wood, the smaller base of a laminate trimmer has less "unsupported" overhang, and is less prone for tipping over as you trim your work piece. They're also good where finer details are necessary, as it's generally easier to see what you're doing when you're going "free hand".

    Laminate trimmer-sized routers generally come with a collet that can handle 1/4" shanked bits. That means you can't stick the larger 1/2" shanked bits into them. They just don't have the power to drive the bigger bits. You can still get an absolutely beautiful result from the smaller router though. It just might take more passes with a narrower router bit to get the job done.

    The second type of routers include the bigger "production" or "full sized" routers. They are generally twice as large, require two hands to operate them, and offer greater power and capability. However, because of their sheer size, don't always suit work done on smaller or more detailed projects.

    Larger routers generally have the larger, 1/2" collet. Which means you can use the 1/2" shanked router bits. If you need to use larger bits, the larger shank (or shaft) of the bit allows for a stronger grip (more surface area) the shaft is considerably stronger, and you can feasibly use much wider router bits. However, remember that the bit has to suit your router base. So keep this in mind.

    Where these production routers truly excel is on bigger projects. You can use bigger router bits, and despite being significantly more powerful and heavy, they're often safer to use, and are less likely to be overwhelmed by knots in wood. In fact, I once routed a piece of wood with an embedded nail (that I didn't know about) and the router simply ploughed straight through it... the only indication that I had done so was the sparks that suddenly showered everywhere, and my router bit chipped it's carbide coating.

    Maybe two types is a bit misleading....

    I want to mention in passing that there's a controversial third type in Australia.

    The third is the "rotary tool", or if you prefer brand names, the Dremel. The Dremel isn't strictly speaking, a router. It's a multi-function tool that just happens to include some small degree of routing capability... but only if you buy the routing attachment, buy the end mills for cutting that way, and only want to cut slots into softer woods. You will never get any typical router bit to fit in the tiny Dremel collet/chuck, there are no fancy edging bits, just straight cutters as far as I am aware. However, for small scale work, and in specific circumstances, the humble Dremel will cut small, straight slots without too much trouble.

    Let's talk about router bases...

    A router "base" is the device that controls the depth of the router bit, and by extension, how deeply it cuts. There are many situations where the depth of the cut must be accurate, and so there must be a way to control it. If you don't, your fancy edges and joints won't line up, and that's never a good thing.

    The simplest type of base is simply called a "fixed base". This is a base where you set the depth of your bit before you start routing, and it does not change (it's "fixed") until you stop, and readjust the base.

    This is a particularly handy type of base for edging, because you know the depth will not drift at all. However, if you want to cut a hole in the middle of a work piece, then there's really no safe way to do that.

    Enter the "plunge base"...

    The plunge base is the most common type of base used today. For the simple reason is that it's more versatile. The plunge base literally allows you to move across the surface of the work piece, then plunge the bit partially, or even all the way through the work piece to make a hole, or stopped slot.

    There's usually some form of clamp mechanism to stop it drifting when you want to "lock it in place" then you can release the clamp, and push the bit down into the wood (or whatever you're routing). Interestingly, if you just release the lock, it's entirely possible that the router will go up, if you aren't careful. This is because there are some springs to overcome the downward force of the router, and this is to stop it "bottoming out" every time you release the clamp. You may need to push the router down quite firmly (with both hands) to lower the bit depth.

    If you have to choose just one type, I'd say go for the plunge type. However, many routers today come with the option to attach both a fixed, or plunge type. Some kits include both in the box, while others you'll have to buy the second base as an accessory. Changing them over is simply a matter of removing the motor (or spindle) from one base, and attaching the other.

    Let's talk about base-related features and accessories...

    The depth stop:

    This is a really handy feature that many people just don't use, I've met people who've been using routers for decades, never using this feature once. So to you dear reader, please take advantage of this feature, it will make you a better router user.

    On plunge bases, you'll often find a "mechanical stop", which is just a rod that stops the depth from going any further. It is usually held in place by a tension knob on the upper part of the base (the bit attached to the motor), which when the router is "plunged" down, the end will hit the bottom of the plunge base.. and funnily enough, the depth stops there.

    You can loosen and raise/lower the stop to set a desired depth, then tighten it back up to lock it in place. There's usually a ruler-like scale to see where the bar has been raised or lowered to. However, it is my experience that the scale is rarely accurate enough to do precision joinery on. So using a set of precision gauge blocks and/or feeler gauges is highly recommended if you need that level of accuracy.

    Sometimes, there's a series of bolts/blocks in a spiral staircase like structure where the rod hits the lower base plate. This is called the "Turret depth stop". Put simply, when doing "deep" routing. It's best to start shallow (the taller steps/bolts), and then turn the block around to the next tallest (without adjusting the stop) and route deeper in a series passes going a little deeper each time.  This ensures that the amount of wood being routed is not going to overwhelm/slow the motor down, and will give you a really nice and smooth cut.

    Here's a nice video showing the depth gauge and turret:




    Let's talk about router bits...

    No discussion of routers is going to be complete without discussing the router bits. Bits come in two categories, based on the thickness of their shaft (or shank). They come in quarter-inch and half-inch shanks.

    Obviously, a half inch bit will not fit in a laminate trimmer which has a quarter inch collet. However, a production router can be adapted to fit both kinds of bits. So make sure you get the right sized bits for your router's collet.

    Moving away from the shaft and more towards the "business end" where the bit hits the wood, you'll quickly learn that router bits come in a huge variety of cutting styles, and each style may have a huge variety variations or sizes. So the question is... where do you start/stop?

    Ok, so some parts of a router bit will be measured in diameter, and others measured in radius. Why is that?

    If you're talking about the shank, or the overall width of the bit (and the resulting hole/groove it leaves in wood), then you're talking about diameter/width. This is important so you know what the bit fits into, and how it will behave.

    The width of a router bit is important when figuring out how fast the router should be spinning. Wider bits need lower speeds. It's entirely possible to spin damaged bits apart if they're huge, and that's not safe. Higher speeds and larger bits can burn the wood it cuts).

    Radius never refers to the overall width of the bit, it describes the tightness of a curve that the bit leaves in the wood. The simplest example is the humble roundover bit.

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    The humble "roundover" bit which merely takes sharp 90 degree edges, and makes it a more comfortable "rounded" edge. Roundovers aren't all equal. Some can have very tight roundovers (radius of a 1.6mm) or much larger, more gentle curve (radius of 12mm) and anything between or even beyond.

    So what bits do I recommend?

    That's a loaded question. Your router use may be very different to mine. However, I'll tell you what I use a lot here so you can just keep it in mind. However, I'll make general recommendations below in my "putting it all together" section.

    The bits I use.

    • Roundovers: Roundovers are pretty much a staple, and I use a 4mm, 6mm, and 8mm most often.
    • Straight cutting bits: I find "straight cutting" bits incredibly useful for cutting wood using jigs, but also for cutting slots, rebates, tenons, box joints, and dados. However the width and length of each bit will depend on what you're doing.
    • Flush cutting bits: Are effectively a straight cutter with a bearing on it, the bearing allows you to move the bit up against a reference edge, and anything sticking out from there gets cut off "flush"(Hence the name). Depending on the bit, the bearing may be at the tip of the bit so you can put your template underneath your work piece, (great for trimming the overhang of benchtops). Or some bits have a bearing between the cutting head and the shank so the template can be put on top of the workpiece. This is the type I use most often.
    • Surface Planing Bit: I use a lot of larger-scale "slabs" or rough-sawn timber, which is never flat. So I use a "surfacing" bit for that, but that's not something everyone will need. It's also a very large bit, so a powerful router is recommended.
      • Side note: If you're interested in this, then I recommend getting a surfacing bit with replaceable carbide blades. This is one place that carbide really pays off.
    • Chamfering bit: Chamfering bits basically slice a straight 45 degree corner off from edges (instead of a round over). Some have bearing to be used like a flush cutter, and others that don't have a bearing and taper to a fine point, can be used to cut V-shaped grooves which can occationally come in handy. Some chamfers do come at other angles... but they're quite hard to find.
    • Finger joints/Tounge and Groove Bits: If you'd like to flooring, or table tops where you're placing lots of boards side-by-side, you can use tounge and groove bits, or finger joints. Those bits are pretty easy to find.

    Wait, what? No fancy edges like "ogees", "ogees with fillets", etc?!


    Truthfully, fancy edges are generally used to make cornicing, picture and/or mirror frames. I've made about a dozen frames, but I find that I don't actually like the fancier cuts. So my kit of fancy router bits goes largely untouched.


    Don't limit yourself to thinking that you can use only one bit to make a fancy frame. Often the "fancier" frames are made of several layers of wood, each using a different bit/cut to make complex profiles. Have fun, and tinker!

    This is a good intro... dating back to when Steve wasn't quite so good at YouTube videos, but the information is good.

    This is a very good introduction to the various types of router bits, but you can skip the shameless ad section from 3:25 onwards. Also, please note that Rockler gear is sold in America, and we're only just starting to see their gear (in extremely limited ranges) here in some of the Australian specialty wood shops. However, there are plenty of alternative sources that are just as good.

    This is a great video showing the difference between plunge and fixed based routers.
    This is about choosing a router. Now I personally find that many US videos on the topic break it down into three router categories, instead of the two I mentioned above. However, I simply haven't come across many in the "middle section". Conversely, my laminate trimmer falls somewhere between the small and middle categories.
    This is a quirky, yet interesting video about what you can do with a router... admittedly with many shop made jigs. However, it just gives you some ideas and perhaps inspiration to have another look at the humble router's ability.
    I've left this one for last, as it's by far the longest. But this shows many things you can do with a router with just a little knowledge.

    Putting it all together...

    Routers come in a variety of sizes, it is important that you choose one that you can handle, and is appropriate for the task at hand. I generally feel the bigger ones, while heavier, are often safer, and offer a smoother cut, but probably aren't the best for finer jobs. Meanwhile, the smaller varieties are better for more detailed work, and ease of use... however they vibrate more, are limited to smaller bits, and the finished cuts aren't quite so smooth.

    Variable speed control:

    Another important consideration is the availability of variable speed control. The speed you need is dependent on the material you are cutting (plastic tends to melt at higher speeds) and the size of your router bit. (Larger/wider bits will burn wood at higher speeds, shortens the life expectancy of your router bits and, perhaps put too much strain on the motor). However, not all routers have this feature, so I'd strongly suggest that you get one with speed control if you can.

    Cordless Vs. Corded Routers:

    Most of the larger routers are still corded by default. It's not surprising really, when you see motors rated at 1500W and beyond. Simply put batteries still can't provide the power needed. If they do, they don't last very long, and the substantial bulk of the batteries make an already heavy tool, even more heavy and cumbersome.

    There are cordless routers at the smaller end. This might be a good option if you only do lighter work, and don't need to run the router for long periods of time. I think the occasional DIY-er is probably suited to this the most, but again, have realistic expectations about what a cordless router can do.

    Dust control:

    Routers make chips and saw dust with almost ruthless efficiency. In fact, a larger router can make as much wood chips as an electric planer, jointer, or even smaller thickness planers. I highly recommend that you find bases with dust control, and attach it to either a shop vac or dust extractor as soon as possible. Many kits come with the parts for dust extraction, but don't have them pre-attached.. so I heartily recommend for your safety (and the ease of cleaning up) that you use it wherever possible.

    Failing that, you should wear a dust mask, eye protection, and hearing protection when using a router. Those blades are spinning very fast, so the particles are being flung fast and far. They can stay airborne for a surprisingly long time.

    Router bits:

    Now I have a slightly controversial view on router bits, and I encourage you to test  things for yourself, and come to your own conclusions. I've included an introductory video above, but I'd honestly recommend that you hold off from buying higher end "bit kits".

    I recommend routing beginners to start with a cheap set of router bits when they're just starting out. This gives you the chance to try a few out, and really get a feel for your new router. If you blunt or break a few... you're not too financially invested.

    Now here's the controversial bit... and it comes in two parts.

    1. Don't buy expensive sets. The sets for expensive kits generally have a couple of really useful bits, a couple of "handy to have" bits, and then the rest is stuff you'll never use. Higher-end manufacturers do this to ensure that you'll always need to buy more than one set, and to offload the ones that don't sell so well. Remember, it might seem like a "bargain" but if you only use 5 bits out of a 10, 15, or (more tragically) 30 bit kit. You've paid far more than you should have. So buy high end bits individually when you have a need for them.. and would use them frequently.

    2. Don't forget High Speed Steel (HSS) bits. Most bits sold these days are carbide coated. Carbide is very useful, it holds an edge longer than steel, and this is where most people stop thinking about HSS bits. In fact, you'll find lots of people basically treating HSS as the "poor mans alternative". What they don't tell you is that HSS is cheaper, they can be sharpened to a much finer edge so they cut better than carbide, and when they do go blunt it's very easy for them to be resharpened at home. If you drop a carbide cutter, it'll probably crack, chip, or shatter.... if you drop a HSS bit, it'll be nicked and you just need to resharpen it with a flat griding stone. I feel that HSS has really gotten a bit of a bad rep unfairly, based on edge-holding capability alone.

    However, whether you have a carbide or HSS bit, you can clean and sharpen them reasonably easily. Just remember to count the number of sharpening strokes on each side so you keep your bit balanced.

    Here's a video that might be handy...


    Ok so the video might not be exciting, but it's actually full of practical tips. Some of the newer videos may be better produced, but come across as too advertisement-like for my tastes.

    Anyway, I've gone a bit beyond "intro to routers", I've discussed the varieties I've seen in Australia, and outlined the differences, desirable features, and linked a bunch of videos to take that even further.

    I have not discussed tools where routers are mounted into machines because that's obviously beyond the scope of an introductory article. However, if you feel you're ready feel free to trawl the Internet to look into the next evolutions:

    1. The router table.
    2. The Wood Rat (a somewhat different take, that is aimed purely at joinery).
    3. CNC Routers/Mills
    Stay safe, and happy routing!
    Ham.

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