Wood router

From Free net encyclopedia

Image:Wood router jmc 2005 03 12.jpg A router is a woodworking tool used to rout out (hollow out) an area in the face of a piece of wood. It was a tool particularly used by pattern makers and consisted of a broad-based wooden hand plane with a narrow blade projecting well beyond its base plate. Since about 1960, it has been replaced by the modern spindle router, which was designed for the same work. Further refinement has produced the even more recent plunging spindle router, which is even better adapted for many types of work. Today, traditional hand-powered routers are often called router planes.

Contents

Moulding

The spindle router has lent itself to the finer end of the scale of work done by a moulding spindle. That is to say it is able to cut grooves, edge moulding, and chamfer or radius the edge of a piece of wood. It is also possible to use it for cutting some joints. The shape of cut that is created is determined by the size and shape of the bit (cutter) held in the collet and the depth by the depth adjustment of the sole plate.

Features of the modern spindle router

The tool usually consists of a base housing a vertically mounted universal electric motor with a collet on the end of its shaft. The bit is height-adjustable to allow protrusion through an opening in a flat sole plate, usually via adjusting the motor-mounting height (the mechanism of adjustment is widely varied among manufacturers). Control of the router is derived from a handle or knob on each side of the device, or by the more recently developed "D-handle".

There are two standard types of router — plunge and fixed. When using a plunge-base router, the sole of the base is placed on the face of the work with the cutting bit raised above the work, then the motor is turned on and the cutter is lowered into the work. With a fixed-base router, the cut depth is set before the tool is turned on. The sole plate is then either rested flat on the workpiece overhanging the edge so that the cutting bit is not contacting the work (and then entering the work from the side once the motor is turned on), or the sole plate is placed at an angle with the bit above the work and the bit is "rocked" over into the work once the motor is turned on. In each case, the bit cuts its way in, but the plunge router does it in a more refined way.

The baseplate (sole plate) is generally circular (though this, too, varies by individual models) and may be used in conjunction with a fence attached to the base, which then braces the router against the edge of the work, or via a straightedge clamped across the work to obtain a straight cut. Without this, the varying reaction of the wood against the torque of the tool makes it impossible to control with the precision normally required.

As an alternative, the tool can also be mounted in an inverted orientation below router tables and used as a miniature spindle shaper. The machine is mounted below the table in the manner akin to a circular saw mounted like a table saw. With such a set-up, it is often advisable that the work be passed over it along a fence. With some router table arrangements it is possible to adjust the bench to give the effect of tilting a saw bench so as to cut with the axis of the tool at an angle other than 90° to the face of the work.


Image:Router bit profiles en.png

Available cutters

Image:Routerbits.jpg Router bits come in hundreds of varieties to create either decorative effects or joinery aids. Generally, they are classified as either high-speed steel (HSS) or carbide-tipped, however some recent innovations such as solid carbide bits provide even more variety for specialized tasks.

Aside from the materials they are made of, bits can be classified as edge bits or non-edge bits, and whether the bit is designed to be anti-kickback. Edge bits have a small wheel bearing to act as a fence against the work in making edge mouldings. Non-edge bits require the use of a fence, either on a router table or attached to the work or router. Anti-kickback bits employ added non-cutting bit material around the circumference of the bit's shoulders which serves to limit feed-rate and thereby reduce the chance that the workpiece is pushed too deeply into the bit, causing the cutting edge to be unable to compensate, which results in significant kickback.

Bits also differ by the diameter of their shank, with ½ inch, 3/8 inch, 8mm, and ¼ inch shanks (ordered from thickest to thinnest) being the most common. Half-inch bits cost more but are less prone to vibration (giving smoother cuts) and are less likely to break than the smaller sizes. The bit shank and router collet sizes must match. Many routers come with removable collets for the popular shank sizes (although in the United States the 3/8-inch and 8 mm sizes are often only available for extra cost).

Many modern routers allow the speed of the bit's rotation to be varied. A slower rotation allows bits of larger cutting diameter to be used safely. Typical speeds range from 8,000 to 30,0000 rpm.

Variations on the theme

A tool similar to a router, but designed to hold smaller cutting bits - thereby making it easier to handle for small jobs - is a laminate trimmer.

Another related tool, called a spindle moulder (UK) or shaper (North America), is used to hold larger cutter heads and can be used for deeper or larger-diameter cuts.

Some profile cutters use a cutting head reminiscent of a spindle router. These should not be confused with profile cutters used for steel plate which use a flame as the cutting method.

Publicity blurb

The router was described as "the most versatile tool in the world" by Jeremy Broun in his book, "The Incredible Router". Hylton and Matlack also describe the router as a versatile tool (see Books below): "You can use it in just about every aspect of a job but assembly ... used creatively, it will do almost any kind of cutting or shaping of wood." However, custom baseplates, templates, or jigs — tools that help guide the router or the workpiece through a controlled motion — are typically needed for more complex cuts.

See also

Books

External links

fr:Défonceuse nl:Freesmachine (houtbewerking)