Operate Routers
Topic 9 – Operate Routers
Routers
The router comes in a variety of styles (see figure 69 below). While the basic is operation remains the same, their application varies. They are all at their essence a motor attached to a chuck which holds a bit. The size of routers varies, and is usually indicated by its motors HP. Routers are available from ¼ HP to over 3 HP and can produce speeds of up to 35,000 RPM. Many routers come with variable speed.
The size of the chuck (known as the collet) can often be changed to fit different sized bits (most commonly ¼” and ½”). The size of the collet must correspond to the size of the bits’ arbor. The depth of the bit can be adjusted at the arbor to a small degree. Many routers also have an adjustable base which is used to adjust the depth of cut.
Router Bits
Router bits come in many different profiles and sizes. Generally, routers are used for trimming and shaping an edge of material. These bits contain a pilot bearing which guides the bit to produce a consistent profile (see figure 75 right). The bit is held by the arbor in the collet while the cutter defines the profile that will be cut. The cutter typically contains deep flutes which are used to collect and expel saw dust as it enters and exits the material.
Some router bits do not have a pilot bearing. These are used for making cuts and profiles within a piece of stock such as roman ogee, dados, and dovetails.
***Considering the variety of sizes router bits come in, what do you think the relationship between the bit and cutting speed is?
Maintaining and Operating the Router
When changing the bit, always check and make sure the power source is removed. The collet is loosened with two specialty wrenches. If the bit becomes stuck in the collet, tap the side to release the jaws and free the bit. When placing the bit in the collet, ensure that it is tight and secure with no movement.
When operating the router, the order and direction of cutting needs to follow specific rules. Do test cuts on a scrap piece when testing for depth of cut. When operating by hand, the router is fed along the material from left to right (when routering inside holes or slots, the operation is completed clockwise). Running the router with the rotation of the blade will result in chattering and jumping of the router. Because of the aggressive cut that routers produce, it is important to be aware of the tear out that can occur. When routering all four edges of a piece of wood, rout the end grain first, then the edges with the grain (see figure 7 right). Alternatively, one may also cut the edges in the following order (in reference to figure 7): 1,4,2, and 3.
Figure 7: the order in which edges of lumber should be routered
For smaller pieces, it is recommended that a router table be used, which is simply a table that is designed to hold the router underneath with the bit protruding through the top. The pilot bearing works the same as with hand operation, or a fence can also be