There are two types of routers: fixed-base and plunge-base (or plunge) routers. Some routers have interchangeable bases, combining both types into one machine.
 

Fixed base

The fixed-base router has a cylindrical housing and a motor that is generally smaller than that of a plunge router. This makes it a little less powerful, but at the same time more lightweight and therefore easier to handle. It is ideal for shaping the edges of shelves.

The handles located near the base provide a stable grip and good control. This type of router can also be attached upside down to a router table, to cut edges, grooves or small mouldings.

Another version, with a smaller body and without side handles, is designed for trimming laminates and is often used to cut sink holes in countertops. The base of this type of router is narrower, which means it can be used nearer the back edge of a counter.

On fixed-base routers, the collet can be adjusted to a specific height.
 

Plunge base

The body of the plunge-base router is generally bulkier than that of a fixed-base router because it contains a more powerful motor. The motor, connected to the base with spring-loaded piston rods, must be pulled vertically downwards for the bit to make contact with the surface of the wood.

Once it is lowered, the router can be locked into this position, thus avoiding the need to hold it down while moving it along.

The handles are designed to make the plunge router (which is heavier than its fixed-base counterpart) easier to handle and assure a good grip for the plunging movement.

A plunge router can be attached to a router table for more demanding tasks such as carving crown moulding or deep grooves.

Combination router

A combination, or interchangeable-base router, is an extremely versatile tool that can accomplish a wide range of tasks. Simply choose the base that is best-suited to the job or that offers the best grip and control for the task at hand.

A woodworker who uses this tool regularly can leave one base attached permanently to the router table and use the other for hand-held operations. It is simply a matter of inserting the motor into the chosen base.

The motor of a combination router looks similar to that of a fixed-base router and is a little smaller than that of a regular plunge router.

1- Variable speed dial
This dial allows you to adjust the cutting speed depending on the density of the material and the bit used. As a general rule, large bits should be run at a lower speed. Average speed varies between 8,000 and 28,000 rpm.

2- Motor
The power of the motor determines how much the tool can handle. The power is expressed in amps (5.7 to 15 A) and in horsepower (0.5 to 3.5 HP). The more powerful the tool, the more quickly and efficiently the bits will be able to cut large pieces of hardwood. The more powerful the motor, the heavier the tool.

1-HP motors are found on fixed-base routers while motors over 3 HP will be on plunge routers. Motors between 1 HP and 3 HP are found both on fixed-base and plunge-base models.

3- Depth adjustment rod
The depth adjustment rod engages the depth stop to stop the plunge action. The rod has a pointer to indicate the depth on a scale, as well as a micrometric control knob for ultra-fine depth adjustment.

4- Handles
The handles on fixed routers are usually round (like knobs) and located near the base, thus ensuring a firm grip and good control. Some models have D-shaped handles, which may be more comfortable to hold and make the tool easier to control during lengthy tasks. The handles on plunge routers are longer, making it easier to push the tool down onto the material.

5- On/Off trigger (not visible)
The plunge router is switched on and off with a trigger located on one of the handles. On a fixed router, the motor is operated with a button located on the body of the tool.

6- Lock-on switch
The lock-on switch locks the tool in the "On" position. This avoids the user having to keep one finger permanently on the trigger and also allows the router to be used in a router table.

7- Collet
The collet (or chuck) is the mechanism that holds the bit in place. Routers usually have ¼" or ½" diameter collets, which can only hold one size of bit. Some machines have interchangeable collets.

Bits with a ¼" shank diameter offer an ideal combination of performance, price and durability for occasional or light jobs. Bits with a ½" shank are more expensive, but they are more rigid and vibrate less, thus providing greater accuracy. They are suitable for frequent and heavy-duty tasks, as well as for working with wider

8- Depth stop
On plunge routers, it is the combination of the depth stop and the depth adjustment rod that enables the user to control the depth of cutting, or depth of plunge (the change in height which the router body will descend to the base plate). The depth adjustment rod engages the depth stop to stop the plunge action. The depth stop has several tiered levels; turning it sets the plunge depth to one of those specific levels. Such adjustment control is necessary when making deep cuts requiring several successive passes. Some routers offer even greater versatility with adjustable depth stops.

On fixed-base routers, the depth is generally adjustable too, via a ring on the base of the tool which raises or lowers the router when turned.

9- Base
The base of a router is covered in plastic to avoid scratching the surface of the wood. This plastic covering can be removed to access the holes that allow you to fasten the tool under a router table.

10- Slot for parallel guide
A parallel guide (or side fence), which may come with the tool or be sold separately, inserts into these slots to help guide the router along the stock and make more accurate cuts parallel to the edges.

11- Piston
On a plunge router, the pistons are rods that enable the tool to move up and down in a vertical movement spanning from 1 3/8" on basic models to over 3" on more powerful ones. When the user exerts pressure on the handles, the pistons move down and plunge the router; when the pressure is released, they pull the router back up again, moving the bit away from the cutting surface. The piston rods are covered with a metal tube or plastic sheath to protect them from dust and wood chips.

12- Spindle lock button
The spindle lock button prevents the shaft from rotating during bit or collet changes. It also prevents accidental start-up, if the router is connected to the mains.

13- Plunge lock lever (not visible)
This lever locks the plunge router in the plunged position, and in so doing, turns it into a fixed router. It can then be attached to a router table.

14- Chip deflector (not visible)
The deflector acts as a shroud to prevent wood chips flying up into the user's face. Some models come with an interchangeable adapter to connect the router to a workshop vacuum cleaner.

Use the following table as a guide to help you choose the most suitable tool for your needs.

Both fixed-base and plunge-base routers can be installed under router tables. In fact, plunge routers of over 3 HP with a ½" collet are recommended to be used this way, since they are more powerful. On some models, the springs can be removed from the piston rods for installation in a router table.

 

Must haves:

• Router bits of various sizes and shapes
• Router table: not absolutely essential, but greatly increases the utility and versatility of the tool

Nice to have:

• Templates and jigs (letters, patterns, dovetail cuts, etc.)
• Parallel guide
• Router compass and guide-rail adapter