Comparison PROXXON LHW 28547 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 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.

— Speed Controller. The ability to limit the engine's maximum speed. Essentially, this function is a smooth speed adjustment; it's convenient when full speed isn't required — for example, in delicate tasks where precision is more important than performance. Note that this feature is found in all types of sanders — including those with a vibrational or belt operation (see "Type"): even in these machines, the vibration frequency or belt speed is determined by the engine's rotations.

— Speed Maintenance. The ability to maintain a set number of rotations regardless of the load on the working attachment. This function is implemented through automation, which adjusts the engine's power accordingly — increasing it under more load and decreasing it under lighter load. Constant rotation speed positively affects both the quality of processing and the lifespan of the working attachments and the tool itself.

— Brushless Motor. The presence of a brushless motor in an electric sander (see "Power Source"). These motors are considered more advanced than traditional brushed motors: they are more energy-efficient, quieter, and do not spark, which can be crucial in fire-hazardous environments. The main downside of brushless motors is their high cost.

— Lighting. This feature is undoubtedly desirable when working in lo...w-light conditions. However, it can also be useful in bright external light: the work area often ends up in shadow (e.g., from the tool itself), making it difficult to work without special lighting.

— Display. A built-in display that can show various information about the device's operation and status. Such a screen provides additional convenience and clarity, but overall, it is quite a specific feature that is rarely found in modern power tools.

— Smartphone Synchronization. The ability to connect the tool to a smartphone or other gadget (like a tablet) via Wi-Fi or Bluetooth. Such a connection is usually used for adjusting work parameters; it's often more convenient to do this through a mobile app than through the controls on the tool itself.

— Rotating Main Handle. The ability to rotate the main handle of the sander around the longitudinal axis. This feature is mainly found in angle models (see "Type") — it provides extra convenience, allowing you to adjust the handle's position according to the situation. This is important for working in unusual positions and hard-to-reach areas.

— Keyless Disc Replacement. The ability to change discs in a sander (usually angle, see "Type") without using keys and other additional tools. The convenience of this feature is clear: you don't need to constantly have a key on hand, keep track of it not getting lost, etc. However, keyless mounting is considered somewhat less reliable than keyed mounting, so it's rarely found in heavy-duty professional models.

— X-LOCK Mounting System. An advanced mounting system for the working attachment, used in some angle machines (see "Type") — predominantly made by Bosch and Makita. This system is somewhat more expensive than traditional 22-millimeter mounting using a nut or washer, but it has several advantages. Firstly, X-LOCK provides the simplest and quickest installation: no need to fuss with additional parts or tools, just place the disc on the spindle and press until it clicks; for removing the attachment, just press a button that disables the lock. Secondly, you can only install the attachment in one correct way relative to the tool — the design of the mounting disallows any other way. The main disadvantage of machines with this system is their incompatibility with cheaper and more common 22 mm standard discs; fittings under X-LOCK are not yet available in every hardware store.

— Collet Chuck. A specially designed chuck used in straight grinders (see "Type"). The grip of such a chuck consists of several elastic petals (usually 2-3) that compress when tightened, securing the working attachment. The main advantages of collets are the speed and convenience in changing attachments, simplicity of design, and low cost.

— Coolant Supply (Coolant). The ability to supply coolant to the work area. This function is mainly found in machines for stone and concrete (see "Type"), as water cooling is most relevant for these materials: it not only prevents overheating but also reduces dust formation. The machine provides a nozzle directed at the working attachment and a fitting for connecting to a water hose.

— Dust Collector Connection. The ability to connect a dust collection container to the tool for collecting dust and other debris generated during operation. Such a container may come with the machine, but this is not guaranteed, and this point should be clarified separately. In any case, a dust collector, while not providing 100% protection against debris, significantly reduces it and simplifies cleanup afterward. Dust collectors can be either reusable or disposable.

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.