How to choose a hand router: expert advice

Recommendation points

• Basic structural elements
• Collet and spindle landing
• Engine: power and control system
• Limiter and revolving stop
• Vertical feed mechanism
• Platform device and equipment

Of all the varieties of hand routers, the most widespread are vertical submersible. This is a very versatile, but at the same time, quite a specific tool, in the selection and acquisition of which knowledge of the features of the device of the main units will help..

Basic structural elements

A hand-held milling cutter is designed quite simply, however, a number of units and mechanisms are not found in other types of power tools. The main driving device is a brushed DC motor, exactly the same as in a grinder or a drill. This is where the similarities end.

Almost all milling cutters do not have a gearbox, the motor armature shaft in them is directly and coaxially attached to the spindle. At the end of the spindle shaft there is a collet with a nut for attaching the cutter to the shank. All assembled elements are placed inside a housing, as a rule, plastic, while the main shaft has a fit on two or three rolling bearings.

The main feature of the hand router is the vertical feed lift. It consists of two racks along which the engine body moves. The legs are spring-loaded and have a movement blocking mechanism for fixing in a certain position. To limit the immersion depth, the design provides a standard adjustable stop with a graduated scale.

Only the least powerful milling cutters have a smooth cylindrical body, while a tool with a sufficiently high power has two handles on the sides for a confident hold during operation. On one of them, as a rule, on the right, there is a start button with a blocker of unintentional activation. There is a vertical feed elevator stop flag on or near the other handle.

The lower part of the tool is represented by a metal platform with a flat sole, on which an anti-friction pad is fixed. The body of the sole can have an arbitrary number of technological holes for attaching a parallel stop, compasses and other equipment. Also, the design must necessarily provide for locking screws to fix the stop guides.

Collet and spindle landing

Collets for hand-held milling cutters have replaceable sleeves for shank diameters of 6 and 8 mm. Rarely enough, and only for powerful milling cutters, the kit can have a sleeve for a 12 mm shank. All elements of this unit: collet body, bushings, clamping nut must be precision. Deviation from the specified tolerances in diameter or the slightest misalignment lead to vibration during operation, which not only reduces the quality of the machined surfaces, but also causes the spindle bearings to fail. The surfaces of metal parts must be smooth, without scoring, the material must be hardened steel with a hardness of at least 32 HRC.

The spindle shaft itself can stand on one radial bearing, however, landing on an additional thrust bearing is often found. The latter is required mainly for milling cutters that are designed to work with vertical plunge in order to remove the load from the motor armature..

Engine: power and control system

There are three grades of cutters: low, medium and high power. High drive performance is required with extended cutter lengths. So, for artistic milling and making grooves up to 10 mm deep, low-power mills with a power of up to 800 W are quite enough. In turn, the processing of edges of countertops, the manufacture of quarters and the carpentry processing of massive parts requires the use of tools with a power of more than 2 kW.

Choose the power of the router carefully: due to the work at high speeds, the gyroscopic effect is clearly manifested, which makes it difficult to hold the tool in your hands. On the other hand, the increase in power is associated with an increase in the size and weight of the tool, which greatly complicates the processing of small parts that require a delicate approach..

Any router should be equipped with a speed governor, preferably an electronic type. The diameter of the cutters can vary over a wide range; therefore, to achieve the correct cutting speed, it is required to set the rotation speed from 10 thousand rpm to 35 thousand rpm. The speed setting range for different milling cutters can vary greatly, this parameter is determined by the type of materials being processed and the size of the cutters that will be used during operation. It must be remembered that the scale of the speed controller is marked conditionally, and therefore the user manual must contain a table of correspondence between speeds.

To work with valuable wood species or artificial stone, the router must be equipped with so-called constant electronics. It is a small spindle speed control unit that maintains the set speed regardless of the load on the motor and the applied mains voltage. Without this option, it is almost guaranteed that there will be non-uniformity of the milled surfaces..

Limiter and revolving stop

Most carpentry operations using a router do not require high precision. The depth of the cutter overhang, as a rule, is set in advance along the ruler and then, in fact, the vertical travel stop is adjusted. However, there are exceptions..

In most cases, the stop is a plastic bar that can move freely inside the sleeve on the side of the body and be fixed with a clamping screw in the desired position. The lower part of the stop rests against the platform on which the stop is located. In almost all modern milling cutters, this part has the shape of a cylinder with a stepped height. The revolving stop is very convenient if, for example, it is necessary to mill a deep groove in several passes, it allows you to quickly change the insertion depth practically on the go. If during the processing of parts there is a high repeatability of technological operations, it is better to choose an adjustable stop, in which screws with lock nuts are screwed into the steps.

There are, however, machining applications that require precise adjustment of the plunge depth without using an additional measuring tool. In such cases, it is required that the stop has a ratchet mechanism to move exactly one millimeter. Additional adjustments are made with a metric microfeed screw in 1 mm pitch. For setting tenths of a millimeter, a graduated sleeve is placed in the area of ​​the screw handle. If you need to improve the accuracy and repeatability of the result, you should give preference to models of milling cutters in which the screw and the stop rod are made of metal, and in the area of ​​the graduated sleeve there is an additional dial with a vernier scale.

Vertical feed mechanism

A vertical lift works in the same way as a bicycle fork shock absorber. These are two strictly parallel polished struts, inside which compression springs are installed. The vertical feed mechanism must ensure the movement of the body along an axis strictly perpendicular to the plane of the router base. For this, the struts are moved inside two cylindrical sleeves with a very tight fit. One of the bushings is split for the possibility of closing the rack in a certain position.

Accuracy of movement, magnitude and smoothness of movement, as well as the force required to compress the springs are the most important indicators for a vertical lift elevator. And if the applied force is a parameter rather from the field of ergonomics, then the accuracy and smoothness completely depend on the technical device of the elevator. For example, due to the adhesion of particles of the removed material on the surface of the racks, they can become jammed, therefore, in a high-quality router, the bushings are protected by anthers, and sometimes there are even corrugated shells of the racks that protect them from dirt and mechanical damage. The amount of lift travel determines the maximum milling depth, it usually increases in proportion to the increase in engine power. It is optimal if in the folded position the collet is flush with the sole or protrudes slightly above it.

Separately, it should be said about the position lock flag. It should be placed in an area that you can reach with your fingers and still work without significant effort. When the flag is pressed at the end of the half-turn, you should feel some kind of click, indicating that the mechanism is securely locked. In this case, the unlocking should not be sharp, otherwise the cutter head may be shot off by negligence..

Platform device and equipment

The base of the router is designed to firmly press the tool to the surface of the workpiece. Without this, precise milling is not possible: the tool simply cannot be controlled. In this case, the sole should slide easily and not contribute to damage to the surface of the workpiece, for which a plastic or composite pad is fixed on it. It must be removable for replacement in case of excessive wear or damage..

The shape of the platform can be round or with truncated segments. The latter is preferable because of the possibility of using flat ends when milling along the guide rail. The inside hole must be wide enough to provide a good view of the milling area. It is desirable to have a transparent protective screen on the side facing the operator. On the reverse side, it is possible to mount a casing with a branch pipe for connecting a vacuum cleaner.

A wide range of accessories is used with the router. It can be like accessories from the tool kit, for example, a parallel stop or a compass. It is desirable that the angle of the edge of the stop be as close as possible to the plane of the sole, otherwise difficulties may arise when working with thin materials. Also, the stop can be equipped with fine adjustment screws – also a very useful function. In addition to standard equipment, self-made devices can also be used: conductors, copying sleeves or special stops. For their reliable attachment to the platform, it must have standard threaded holes or be allowed to make them independently..