Routing Basics - Part 1 - Canadian Woodworking Magazine

Skill Builder: Perhaps no more than forty or fifty years ago, grooving, decorative edge work and intricate joinery in most small wood shops would have been done by a wide range of hand tools.

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Routing Basics - Part 1



The introduction of the hand held router has significantly changed the way we work. The first routers certainly were not the sophisticated woodshop workhorses we use today.

Long gone are the days of a simple motor with limited adjustability spinning a steel bit with a ¼" shaft at a single speed.The new generation of routers offer more versatility, power and features than ever before, and woodworkers are taking to them like ducks to water. Like any other woodworking tool, routers can range from the most basic, inexpensive model to more expensive versions packed with features that dramatically expand the routers' capabilities.
 

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Choices, Choices, Choices...
The array of styles, prices and features can make it challenging for you to select the right model. When choosing your first router it is best to think about the type of work you will most likely be doing with it. Heavy-duty joinery and cabinetwork will require a larger router, but if all you want to do is some decorative edge treatments, one of the smaller versions will do. (See Mid-sized Router Review, June/July 2006, Issue #42).

At the risk of oversimplifying things, most routers generally fall into three basic categories based on their power rating: small, medium and large. Small routers (or laminate trimmers) under 1 HP, like the Bosch Colt are generally used for light duty operations. They can only be used with bits that have ¼" shafts. These are great when you need to bevel or round over an edge, cut a shallow mortise for hardware or trim laminate flush. They don't have the power and features of their larger cousins, but they often ship with accessories and attachments for different operations.

At the other end of the spectrum are the large 3 ¼ HP routers, like the Freud FT3000VCE, that can handle anything you throw at it. These routers are much heavier, but have the power to muscle through the most demanding operations. They also tend to be at the top of the pack when it comes to price and features, though often accessories like fences, circle-cutting attachments and guide bushings are sold as options. These bigger routers will also allow you to use larger bits that have a ½" diameter shaft.

Perhaps the most common router is the medium sized one, like the Bosch 1613AEVS or Freud FT1700VCEK. These fall in the 1 ½ to 2 ¼ HP range. In the majority of cases this is plenty of power for most tasks that you will likely be using the router for. The majority of the routers in this category will have two collets (the mechanism that secures the bit to the shaft of the motor) to allow the use of bits having either ¼" or ½" shafts.


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Laminate router (left)

Size Isn't Everything
Routers come in two different styles – plunge or fixed base. Power considerations aside, this is the most critical factor determining what the router can, and cannot do. Fixed base routers have minimal bit height adjustment and are generally used when you can approach the work piece from the edge. They also tend to be lighter and more compact than the plunge versions, making them somewhat easier to handle.

Plunge base routers allow the bit to be started above the work piece and then the whole motor and bit assembly is lowered into the work piece. This is necessary when routing an opening inside a larger panel, cutting mortises, and when routing stopped dados, grooves and similar operations where it is not possible to bring the bit in from the edge. The motor moves up and down on two posts with internal springs providing upward motion. When the router is started and the plunge locking mechanism is released, the operator plunges the router into the material to a preset depth.

A more recent innovation is the 'combo router', like the Bosch 1617EVSPK – a medium-sized router motor in a kit with both a plunge and a fixed base. This gives you the advantages of both styles in one tool. When you can afford to buy only 'one' router, this is the way to go.
When choosing a router, try to get your hands on the models you are comparing and note how smoothly the plunge mechanism operates as well as the other features and how easy they are to use. With your hands on the handles, pay particular attention to how easy it is to access the various features like the on/off switch and the plunge lock mechanism without removing your hands from the handles.


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Use an adapter for non-standard shank sizes

Watch Your Speed
Routers are high RPM machines and under most circumstances will provide you with a flawless finished surface, assuming you are using a sharp bit. Single speed routers are fine for the majority of bits less than 1 ⅛" or so in diameter, but as the diameter and mass of the bit increases, the speed must be reduced. Fortunately, most routers now come with a variable speed motor. Routers are loud, screaming machines and reducing the speed of the bit to the slowest speed possible without affecting the quality of cut will reduce the noise considerably. The larger the diameter of the bit, the faster the edge will be traveling as it meets the wood. Some woods like cherry and maple burn easily when the router bit is spinning too fast; slowing the bit down will prevent the black marks that are all but impossible to sand out of complex profiles.
 
Other Considerations
Depth stops limit the bottom end of the travel when plunging the bit into the work from above. Some of these are easy to use, others can be somewhat awkward, so it is best to try out the models before making a purchase. Some even have multiple depth settings on a rotating turret that allows you to set multiple commonly used depths. In addition to the depth stops, a precision adjustment will let you get close to the setting you need and then dial in the exact setting.

One feature that is beginning to show up on routers is a graduated depth stop. After setting the final depth of cut, this graduated stop is used to remove the material in several controlled passes until the final depth is reached. Making the cut in several passes is easier on the router as well as preventing large chunks of wood from being torn out of the piece being routed.

Routers with variable speed control often come with a soft start feature. This reduces the tendency of the router to jerk in the opposite direction of the motor rotation at start-up by gradually applying power until the router reaches full speed. Most routers with this feature also have an electronic feedback circuit that monitors the speed of the router and maintains constant speed regardless of the load imposed on the motor.


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Set the depth stop

Bits With Bite
Until you install a bit, the router can't do anything, and the vast range of bits available is what gives the router its versatility. Bits come in several different shaft diameters with ¼" and ½" being the most common. Some bits (profiles) are available in both shaft diameters but others are available in only one or the other. When purchasing a router, choose one that can handle both sizes. Some jigs like the Leigh D4R dovetail jig and the Leigh FMT mortise and tenon jig use bits with other diameters. In these cases an adaptor is used to bring them up to the ½" size the collet can handle.

The ¼" shaft bits are less expensive and can work well within certain limitations. They are, however, meant for light duty work. Using a dull bit or forcing the bit through the work too quickly can cause it to snap off at the shaft. These bits also tend to chatter and vibrate more, which will result in a rougher finish. Better quality bits designed for more demanding work have larger ½" shafts. These are much more stable in use, have less tendency to chatter, and provide a smoother finish.

The cutting edge on the bit is also crucial. At one time, high-speed steel bits dominated the market but these have lost ground to the higher quality carbide tipped bits. High-speed steel bits are inexpensive and will give you a high quality cut, but they will dull very quickly. They are also getting harder to find as the price of carbide tipped bits continues to fall as new methods of manufacturing come on-line.

Not all bits, carbide or otherwise, are created equally. While it is possible to purchase a complete starter set of 30 carbide tipped bits for less than $40 on sale, these are not the same quality as bits made by a manufacturer like Freud or Bosch. To bring the cost of these sets down, certain sacrifices are made during the manufacturing process. Reputable bit manufacturers start with a high grade of steel and manufacture their own carbide, which they then affix to the steel bodies. The higher quality bits are manufactured with a micro grain carbide formulation and each bit is perfectly balanced. With the bit perfectly balanced, there will be no vibration as it spins and this will result in a perfectly smooth cut. Not only is the resultant cut of a higher quality, but as the micrograin carbide bit wears during use, the pieces that wear away are much smaller in size, which means that the bit retains its sharp cutting edge longer. An unbalanced bit will introduce vibration into the shaft of the router, which will lead to excessive heat build up and wear on moving parts such as the bearings.
 
A Bevy of Bits
Bits generally fall into two categories: profile bits, and joinery bits. Profile bits are typically used for adding decorative edges to a project, such as a round over bit to soften the edge of a table, or an ogee bit for profiling the edge of a drawer front, or a v-groove bit for sign making. These come in a dazzling array of styles and sizes to suit almost any style of furniture.

Where the router really shines is its ability to handle various forms of joinery during the construction phase of a project. Using specialized cutters in combination with jigs, it is possible to produce an amazing range of joints, from dovetails (sliding, half blind and through), mortise and tenon, tongue and groove, and even rail and stile doors with a raised panel. The profile and format of the cutter determine its use.

Router bits are available in two forms – piloted and non-piloted. A piloted bit has a small ball bearing guide mounted on the top (or in some cases, on the bottom), which runs along the edge of the work piece to guide the cutting edge of the bit.

If the bit does not have this feature, the router must be used in combination with an edge guide (if the router is hand held), or a fence (if it is mounted in a table). Using a piloted bit it is possible to profile a curved edge, such as an arched raised panel door. When using a piloted bit it is a good idea to periodically check the screw that holds the bearing in place as these can occasionally come loose and allow the bearing to separate from the bit.

Frame and panel door construction is a common way to combat the effects of seasonal wood movement. By placing the solid wood panel inside a frame, any expansion of the center panel is contained by the outer frame, which means that the door will not change in width from one season to another, resulting in a perfect fit year round. Cutting the joinery for the frame members for this type of door is done using matched bits on a router table. These can either take the form of a matched set of bits, one for the rail and one for the stile, or a reversible bit that can be reconfigured for either operation. Although the matched sets containing both a rail and a stile bit are more expensive than the reversible sets, the profiles fit each other exactly and are much more convenient. These bits can only be used with the router mounted in a table.


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Piloted bit (top), Unpiloted bit (bottom)

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Frame and panel bit

Accessories Not Always Included
A router right out of the box is ready to use. Install a piloted round over bit and you’re ready for life on the edge. But to get the most out of your router there are several accessories that will greatly increase the range of operations that you can perform. Most router manufacturers offer these as options when purchasing your router. Some, like the Triton plunge router, even include an impressive collection of these as standard equipment. An edge guide acts as a portable fence that moves with the router allowing the bit to maintain a constant distance from the edge of a piece, as when cutting a dado parallel to an edge.

A circle guide is quite handy when making an object like a round table top. The guide is fastened to the center of the top and the router is attached to the base at a distance from the center and is then run around the perimeter resulting in a perfectly round circle.

Another method of guiding the router involves the use of template guides that attach to the base plate of the router. These are used to guide the router in combination with various types of joinery bits when following a template or jig.

Because many woodworkers use their routers in a table for most operations, manufacturers have recently started equipping routers with above the table adjustment mechanisms. With the router mounted in a table, the controls that are normally well placed for hand held use can be much more awkward to reach. To address this situation router manufacturers are designing new models that include a method of adjusting the bit height from above the table. This usually involves a crank of some sort that passes through a hole in the top of the table to engage the plunge mechanism. Another function that has become popular in combination with these above the table mechanisms is an automatic shaft lock. As the collet travels through the hole in the router table, a locking pin is pushed into place to engage a hole in the shaft of the motor that keeps the shaft locked in place. This allows for bit changes using just one wrench.
 

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Setting height adjustment

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Router table template guide

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Guide bushing on router

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Above table height adjustment

Take Control of Your Router
The router is easily the most versatile power tool in your shop, and when used in combination with various accessories there is almost nothing that it cannot do. From flattening large slabs of lumber to cutting functional as well as highly decorative joinery, the router can do it all. In some cases you will need to fabricate specialized jigs and guides, but the creativity and control the router puts at your finger tips is unmatched by any other tool in your shop. - CWM
 
In upcoming articles in this series we will take a look at safely using the router for various hand held routing operations, routing using a router table and various router jigs.

Router, bits and/or accessories are available at: