Comparison Einhell Classic TC-BJ 900 vs Black&Decker KW900EKA

The general design features and purpose of the router depend on the type.

— Vertical. The classic, most common type of milling cutter. Usually, vertical devices consist of the motor itself and a sole of a special design that provides support during operation. The sole is often made adjustable in height, which allows you to change the distance that the cutter protrudes and, accordingly, the depth of processing. However, this change can be done in another way.

— Edge. As the name suggests, this type of router is mainly used for edging and chamfering. Such units are lighter and more compact than vertical ones, which, in particular, facilitates work in cramped conditions. On the other hand, they are less performant and have less customization options (in particular, they are very rarely equipped with depth adjustment).

— Lamella. Specialized milling cutters designed for cutting grooves for lamellas — fasteners in the form of thin plates. The design of such a tool is such that each groove is cut literally in one movement — this greatly speeds up and simplifies the work. For other purposes, lamellar routers, usually, are not intended.

— Additive. Similar to the lamellar ones described above, filler mills are used to cut out “seats” for fasteners. However, in this case, these places are intended for dowels — o...blong products with a round or elliptical section (also known as chopiks or dowels) and are not grooves, but holes, usually quite deep.

— To remove varnish. The purpose of this type of milling cutter is clear from the name: they are used to remove paint and varnish coatings; the principle of their work is similar to angle grinders ("grinders"). Varnish stripping jobs often deal with fairly large areas to be treated, so this type of tool usually allows the use of large cutters that provide a large working width. In this case, the engine power may be low, because. the load on the cutter in this case is small.

— Milling motor. This type can be described as minimally equipped routers — consisting of a motor in a housing, a spindle and a collet and devoid of a sole, guide rails and other similar devices. Usually, such tools have an elongated body and a rather small size and weight, which gives quite extensive possibilities for their use — from working as an impromptu manual engraver to installation on an automated machine. However, in most cases, router motors will still require additional attachments.

— For cutting tiles. Another type of milling cutter, the purpose of which is described by the name. By themselves, such devices have an oblong body and work similarly to drills; however, the case is not limited to round holes along the diameter of the cutter — the cutter can also cut a line in the material, for example, to create a hole for an exhaust fan, or to cut a fragment of a non-standard shape. Such features are indispensable when working with tiles.

— Disk. Milling cutters using a cutting nozzle in the form of a disk. Their main purpose is to cut grooves. By design and principle of operation, milling machines of this type are similar to circular saws, however, an equal sign cannot be put between these tools. Unlike saws, circular routers do not cut through the material—they only create a groove of a certain depth, usually a V-profile, in the surface. Also, they use milling cutters instead of saw blades. One of the most popular applications of such a tool is cutting fold lines on aluminium sheets.

The total power of the router, more precisely, the engine installed in it. The higher this indicator, the more productive the device is, the better it copes with complex work, the more force on the cutter (torque) it provides during operation, and the greater the spindle speed can be (although a powerful tool is not necessarily high-speed). On the other hand, high power significantly affects the dimensions, weight and price of the tool, plus power consumption and network load increase accordingly. In addition, high torque in some cases (for example, with delicate processing) is frankly undesirable. Therefore, a tool should be chosen according to this parameter, taking into account the real needs and the specifics of the planned work.

There are three main categories of milling cutters in terms of power: light (up to 700 W), designed mainly for simple household work; medium (up to 1500 W), able to cope not only with domestic, but also with most professional tasks; and heavy (1500 W or more), used in cases where high power is critical. However, this gradation is true only for routers (see "Type"), other varieties have their own specifics: for example, lamellar models, in principle, do not need high power.

The slowest spindle speed (in revolutions per minute) provided by the router motor.

For different jobs, the optimal spindle speed (and, accordingly, the cutter) will also be different. For example, hard materials like stone require fast rotation, but wood does not; some types of nozzles work better at high speeds, others at low speeds, etc. Detailed recommendations for each specific case can be found in special sources. Here we note that the smallest value of the minimum number of revolutions found in modern milling cutters is about 3000 – 5000, and in the most "fast" models this figure can exceed 15000. When choosing, pay attention not so much to the minimum rotation speed as to the total speed range — how it corresponds to the planned tasks.

The highest spindle speed provided by the router motor. Measured in revolutions per minute. For models that do not have speed control (see "Functions"), this paragraph indicates the standard number of revolutions.

For different work, the optimal speed of rotation of the spindle (and, accordingly, the cutter) will also be different. For example, hard materials like stone require fast rotation, but wood does not; some types of nozzles work better at high speeds, others at low speeds, etc. Detailed recommendations for each specific case can be found in special sources. When choosing, it is worth paying attention not so much to the maximum rotation speed as to the general range of speeds - how much it corresponds to the planned tasks. We only note that in models with a large allowable cutter diameter (see below), the maximum rotation speed can be relatively low - the working edge of a large cutter moves quickly even at low speeds, and for effective acceleration of such a nozzle, too much power would be needed.

The largest collet size that the router can use.

A collet is a special type of fastening used, in particular, for installing working nozzles in milling cutters. For proper installation, the size of the collet must match the size of the cutter shank. Modern cutter shanks and collets for them have standard sizes - 6, 8 or 12 mm. The larger the size, the larger the cutter itself, the more powerful the tool and the more difficult the work for which it is intended.

As a rule, the maximum size of the collet is the size of the fixture that is standardly installed in the router. Thinner cutters can be mounted using special adapters (however, care must be taken, as such a nozzle may not be designed for the increased power characteristic of tools with a large collet).

6mm collets are found predominantly in light routers (see "Power"), 8mm mounts are found in most intermediate and professional level tools, and 12mm collets are found in the most powerful and heavy models.

The largest diameter of the cutter that can be installed in the router.

The larger the cutter, the faster its cutting edge moves and the more material it can capture, but larger nozzles require more torque. Accordingly, the maximum diameter of the cutter is directly related to the power of the tool (see above): the larger the allowable size of the nozzle, the more powerful and advanced, usually, the router is. However, large cutters (as, in fact, high power) are not always really needed. Therefore, when choosing according to this parameter, it is worthwhile to adequately evaluate the upcoming work and not chase the maximum size.

The greatest depth of grooves or holes that the router can make. This parameter is relevant only for lamellar and filler models (see "Type") — in other varieties, such a parameter as the stroke value has a similar value (see below). In most cases, the maximum groove depth does not exceed 30 mm — this is quite enough to use the lamellar / filler router for its intended purpose. In some professional models, this figure can reach 70 mm, but this is very rare.

The distance by which the height of the cutter can change relative to the support platform of the router, in other words, to what depth the working nozzle can be lowered relative to the upper position. This parameter is used for vertical and edge models (see "Type"); however, edge routers with height adjustment are very rare. In fact, the amount of travel not only describes the maximum working depth provided by the tool, but also indicates the presence of depth adjustment; for models without such adjustment, this parameter is not indicated at all.

As for specific numbers, for simple household work, a stroke of 25–30 mm is considered quite sufficient, and in a more serious tool, values of 70–80 mm can be found.

— Soft start. The presence of a soft start engine in the design of the milling cutter. A feature of most modern electric motors is that when connected to the network directly, without control circuits, at the time of start-up, there is a sharp jump in current through the motor. This, on the one hand, creates voltage fluctuations in the mains (which can “knock out” fuses or become fatal for some devices operating nearby), on the other hand, it leads to a sharp jerk of the tool, due to which it can be released from hands (and this cause damage to surrounding objects and even injury). This function also limits the current at the moment of starting the motor. Due to this, the speed increases smoothly, without jerking the tool, and the power grid is not subjected to excessive overloads.

— Adjustment of frequency of rotation. The presence of a speed controller in the design of the milling cutter. This function allows you to change the spindle speed, adjusting it to different types of work — for example, to effectively cut hard material, you may need a high speed, and with soft woods, you can work at low speeds. Tools with speed control will be useful especially for those who have to deal with a wide variety of materials. In this case, the range of such adjustment may be different.

— Microlift. The presence in the design of the router of a system for fine-tuning...the depth with an accuracy of 0.1 mm. The standard setting with the limit pin is very coarse, as the errors are quite large. The microlift is used where it is important to set the depth very accurately. It is implemented mainly by means of a threaded connection that limits the vertical downward movement, or is completely integrated into the vertical travel design, where unlocking is not needed to make the necessary adjustments.

— Backlight. The presence of a lighting system in the design of the router — in fact, an ordinary flashlight that facilitates work in dimly lit places. The need for backlighting may arise even in daylight or bright artificial lighting — the place of work is quite often in the shade (for example, from the head of the operator himself).

— Maintain momentum. The presence in the design of the milling cutter of a system that automatically adjusts the engine operation mode depending on the load on the working nozzle — in such a way that the rotational speed remains constant, does not fall under load and does not increase at idle. Thanks to this adjustment, a constant quality of processing is ensured, practically independent of the pressure on the nozzle, wear of the nozzle and the tool itself is reduced, as well as overall energy consumption.