Comparison PROXXON LHW/A 29815 vs PROXXON WP/E 28660

The type of grinder determines the design features and the operation of its working mechanism.

— Corner. One of the most common and versatile types of grinders. The name is due to the device of the working mechanism, in which the drive axle and the spindle with the working nozzle are located at an angle of 90 degrees and are connected through a gearbox. It is this type of grinders that is unofficially called "grinders". The working tool is a grinding wheel. Angle grinders are used for grinding, polishing, roughing and stripping metal, concrete, brick, cement, marble and granite products. Design features also allow the use of such a tool for cutting metal and cleaning welds.

— Direct. In straight grinders, the drive shaft of the electric motor and the spindle with the working nozzle are located on the same axis, which led to the name. Most often they are used for small and precise work, they are convenient for processing hard-to-reach surfaces (the length of the spindle is of great importance). As a working tool, finger and conical grinding wheels, cutters, brushes can be used. Not designed for use with large grinding wheels such as those used in angle grinders.

— Tape. The working element of such grinders is a sanding belt connected into a ring and moving along guide rollers. Such devices are designed for rough processing and leveling of flat surfac...es, as well as the preparation of edges and bevels. Tape models have a fairly high performance, but are not designed for accurate delicate processing; in addition, they are intended mainly for relatively narrow parts, the width of which does not exceed the length of the tape (brush / drum devices are better suited for large surfaces — see below). Also note that grinders of this type do best with wood, although sanding belts are also available for other materials, including metal, concrete, plastic.

— Eccentric. In eccentric grinders, the working tool (sanding sheet) performs two movements simultaneously: rotational and vibrating. Due to this, high quality processing is achieved with good performance. These machines are well suited when a large amount of material has to be removed during fine finishing work. Unlike vibration grinding, they allow you to process not only flat, but also convex and concave surfaces.

— Vibrating. Orbital sanders use a vibrating sanding sheet driven by an eccentric on the motor shaft. With a relatively low productivity, such a scheme provides high accuracy and quality of processing. Vibration grinders are used for fine finishing of flat surfaces.

— Delta grinding. In fact, they are a kind of vibration grinders (see above), but they differ from them in the shape of the grinding sheet: it is triangular, resembling the Greek letter “delta” in shape (hence the name). Due to this, as well as their small size, these machines are well suited for working in hard-to-reach and difficult places, such as corners, edges, curves, etc.

— Multifunctional. Machines operating on the vibration principle, however, combining the capabilities of several varieties at once. Such versatility is realized through interchangeable soles, which, usually, are supplied in the kit. Thanks to such accessories, a multifunctional grinder is able, at a minimum, to turn from a conventional vibrating (with a rectangular sole) to a delta vibrating (with a triangular one) and vice versa; and some models are also equipped with a round nozzle and can also work in the eccentric format. Such a tool will be the best choice for those who have to deal with a wide variety of tasks for a vibration format machine: one universal machine with a set of interchangeable accessories is much cheaper than several more traditional tools with similar characteristics. On the other hand, a multifunctional model handles worse with each specific task than a specialized unit of a similar cost. Simply put, at the same price, a universal machine “can” more, but a specialized one (vibrating, delta grinding, etc.) is more effective in its particular area.

— Polishing. A type of angle grinder specifically designed for finishing various surfaces. Technically capable of working in grinding mode, however, the main function is still polishing and final finishing of the material.

— Brush / drum. Grinders of this type are generally similar in layout to angle grinders (see above), and the main difference is that the working nozzle does not have the shape of a flat disk, but of a characteristic cylinder, the length of which noticeably exceeds the diameter. If such a cylinder has hard bristles (usually metal) — the machine is called a brush, in other cases — a drum; however, there is no fundamental difference between these varieties, in addition, many models allow the use of both types of nozzles. This nozzle format is especially suitable for processing large flat surfaces, for which tape machines are poorly suited; specifically, the brushes are very effective, in particular, when removing paint and varnish coatings. On the other hand, removing paint is just one of many tasks that sanders have to deal with; and with other types of work available for this type of machine, vibration (including delta grinding) and eccentric models (see above) also do a good job. In addition, rotating cylindrical nozzles are not particularly accurate, they are not suitable for delicate work that requires care and precision. That is why grinders of this type are relatively rare nowadays.

— Wall grinder. A specific feature of most wall grinders is an elongated design that includes a characteristic rod (see "Complete set"). This allows you to grab a large section of the wall without moving from your place, as well as work at high heights without using stools or other similar supports. However, wall grinding models are produced without a rod. Such devices, usually, are a slightly modified version of the angle machines described above. Of the differences, in addition to the use of a rod, one can also mention the method of attaching the working nozzle — it is installed on Hook-and-loop or other similar devices, similar to how it is done in an eccentric tool.

— Grinder for concrete. Most stone/concrete grinders are similar in design to angle grinders (see above), although there are other variations. Anyway, such tools are quite powerful, and their design is designed for long-term operation in difficult conditions: for example, overload protection is often found (see "Additional"), a system for supplying water to the place of work, etc. can be provided.

The power consumed by the grinder during operation. Usually more than the output (useful) power (see above) due to losses during the conversion of energy from electrical to mechanical. However, the general patterns in this case are the same: a more powerful tool, on the one hand, is usually more performant, on the other hand, it is heavier, larger and more expensive. In addition, the total electricity consumption depends on this indicator; however, grinders, even the most powerful ones, consume relatively little energy, and difficulties can arise only when connecting a high-performance professional tool to weak electrical wiring.

Note that it is much easier to determine the consumed power than the useful one; therefore, only this parameter is often indicated in the characteristics, without specifying the useful power. In general, it is quite possible to compare grinders of the same type using it (see above): a modern tool has approximately the same efficiency, and in most cases the useful power values bare related in the same way as the consumed values.

The speed of rotation of the working attachment, which is capable of providing a grinder of the appropriate design (for example, angle — see "Type"). If the device has speed control, this paragraph shows the range of such adjustment, from minimum to maximum.

It makes sense to compare by this parameter units belonging to the same type and having the same maximum diameter of the disk (or other working nozzle). The latter is due to the fact that the larger the disk, the faster its edge moves (at the same speed); i.e. a larger diameter requires less RPM for the same performance/efficiency. In general, when comparing different models, the following should be taken into account. The higher rotation speed is well suited for large volumes of work (because it improves productivity) as well as for fine polishing with “delicate” nozzles. A lower setting, in turn, improves accuracy (reduces the chance of removing excess material), as well as provides more torque and allows you to more effectively deal with hard, stubborn materials. More detailed recommendations for different types of work and different nozzle diameters can be found in special sources; here we note that an increase in the rotation speed, usually, affects the cost of the machine compared to analogues (since this requires a more powerful engine). In addition, discs and other attachments may have maximum RPM limits.

— Network. Mains power is suitable for tools of any power, and the continuous operation time is almost unlimited (as long as there is mains voltage and the tool does not overheat). The disadvantages of this option are the dependence on sockets and the presence of a network cable, which limits mobility and can get tangled under the arms, creating inconvenience during work. However, these moments are relatively rarely critical, so most modern grinders use mains power.

— Battery. This type of power makes the tool as autonomous as possible, allowing you to work even in the absence of sockets and easily move from place to place. In addition, the absence of a network cable is also a serious advantage. On the other hand, a cordless tool is noticeably more expensive and heavier than a “network” one similar in characteristics; the power of such grinders is relatively small — otherwise too bulky and expensive batteries would be required; and the battery life is limited, and after the depletion of the energy reserve, you have to take a long break to recharge the battery. So this option makes sense to consider only in cases where mobility and lack of wire are critical.

— Pneumo (compressor). Connection to the compressor supplying air using a hose. On the one hand, this option is not very convenient, because it requires the compressor itself; and the hose restricts freedom of movement and can create othe...r inconveniences when working. On the other hand, pneumatic machines themselves are simpler, cheaper, lighter and more reliable than electric ones, they are less prone to heat and are better suited for long continuous work. In addition, such a tool is indispensable in some specific conditions — for example, at high humidity, when there is an increased risk of electric shock, or in an explosive environment, when sparking in mechanisms is unacceptable.

Most modern power tools use replaceable batteries, and then this paragraph indicates the number of such batteries. It is worth saying that the most popular version of this configuration nowadays is 2 batteries. It is relatively inexpensive and at the same time allows you to minimize, if not eliminate interruptions in work: while one battery is in use, the second can be charged, and when the charge is exhausted, the roles change. In this regard , single battery kits are not particularly common: they are mainly entry-level tools that are not designed for long-term use and allow interruptions to recharge the battery.

In addition, quite a few modern cordless tools come in a configuration colloquially known as a “carcass” — namely, no batteries at all. This option is relevant mainly for two cases: if the user wants to choose a power source separately, at his own discretion, or if such a source is already on the farm. Regarding the second option, it is worth noting that many large manufacturers use universal batteries suitable for different types of branded power tools. So a battery, for example, from a previously purchased jigsaw or drill may well be compatible with a grinder of the same company.

As for non-removable batteries, this is a rather rare and specific option. Such tools are as compact as possible, but the batteries t...hemselves cannot be quickly changed — so you will inevitably have to take breaks for charging during work. Therefore, this method of supply is typical for low-power instruments. In them, small size is more important than a long period of continuous operation, in addition, a low capacity allows you to achieve good battery life even with small sizes (and, accordingly, capacity) of batteries.

The operating voltage of the battery in the grinder with the appropriate power supply (see "Power supply"). The more powerful the tool, the higher the battery voltage, usually. At the same time, this parameter is usually selected in such a way as to optimally match the characteristics of a particular model; therefore, in fact, voltage data may be required only when looking for a spare or additional battery.

The capacity of the battery that is equipped with the tool with the appropriate type of power (see “Power source”).

Theoretically, the capacity directly determines how long the tool can work on one charge. However, in practice, this parameter is rather weakly related to real autonomy. Firstly, the charging time depends not only on the battery capacity, but also on the energy consumption (power) of the tool itself; secondly, the actual amount of stored energy is determined not only by the capacity in ampere hours, but also by the voltage in volts. So you can only compare tools with similar power and the same battery voltage in terms of battery capacity.

Note that some models of grinders allow replacing the “native” battery with another, including a higher capacity one; some manufacturers even produce universal batteries suitable for different types of power tools under a given brand.

Battery models that the device of the corresponding type is compatible with (see "Power source"). This information will be useful in cases where the battery(ies) must be purchased separately, for example, if the tool does not come with a battery at all, if you need to supplement the original package, or if the existing battery has failed.

The total weight of the grinder; for battery models (see "Power Source"), usually, it is indicated without taking into account the battery.

This indicator has two meanings. On the one hand, light weight has a positive effect on manoeuvrability and reduces fatigue during work — especially when processing vertical surfaces and ceilings, as well as in other situations where the tool has to be held on weight. On the other hand, for grinders with a vibrational principle of operation (see "Type"), used for processing horizontal surfaces, a significant weight is considered optimal: it allows the tool to fit closer to the material being processed, and also contributes to stability and retention. So when choosing such a model by weight, it is worth considering the features of its intended application.