Comparison Alpina SC40G vs MTD Optima 38 VO

The type determines the method of operation and, accordingly, the general purpose and specific application of the aerator.

— Verticutter(knife). The name comes from the English "vertical cutter" — "vertical blade". In accordance with this, the working tool of the verticutter is a horizontal shaft with vertical blades mounted on it. In the process of work, such an aggregate leaves characteristic slots in the ground, which contribute to the penetration of air, moisture and nutrients into the soil. In this case, the blades cut the roots of the grass, thus stimulating their growth in loosened soil and, accordingly, the growth of the grass itself. In addition, verticutters are good (better than the scarifiers described below) for removing debris from the surface of the earth. They easily cope with both “lying” debris like wood chips or acorns, as well as with dry grass, moss cover, etc. Therefore, the main purpose of such units is the cleaning of neglected lawns that have not been cultivated for a long time, which require intensive processing. It should be noted that verticutters also include hand-held devices (see "Engine type") with a working tool in the form of characteristic "sprocket" wheels: according to the specifics of work, they are a cross between rake and knife models, however, the teeth of the "sprockets" are more similar on knives than on the antennae of scarifiers, and they penetrate deeper....

— Scarifier (rake). Aerators of this type work on the principle of a wire rake: like verticutters, they use a working tool in the form of a shaft, but not blades are installed on the shaft, but wire “antennae”. Thus, most scarifiers do not so much work on the soil as they comb the lawn, removing debris from it — like last year's leaves or dry grass. However, there are models that are able to pierce the soil; however, even with them, the depth of influence is very small — up to 5 mm. In general, such units are designed mainly to maintain healthy already “cultivated” lawns that do not require intensive processing.

— Combined. Models that can be used both as a knife aerator and as a rake aerator. Features of both types are described in detail above. And to realize their functions in one aerator, it is possible through the use of interchangeable shafts: by installing the appropriate shaft, the owner can turn the unit either into a verticutter or a scarifier. Note that only those units that are initially equipped with working tools of different types belong to the combined ones. If the possibility of replacement is provided, but there is only one shaft in the kit, the aerator will be assigned to one of the types described above.

The width of the strip processed by the aerator in one pass. The higher this indicator, the faster the device works, the fewer passes will have to be made to process a certain area. On the other hand, a wide grip noticeably affects the dimensions of the entire structure and makes it difficult to work in hard-to-reach places, if not impossible. Therefore, when choosing a model in terms of working width, it is worth considering not only the overall dimensions of the site, but also its configuration and the presence of tight areas — sometimes it is preferable to sacrifice the performance of the aerator for the sake of its manoeuvrability and patency.

The number of nozzle depth adjustments provided in the design of the aerator. Note that we can talk not only about the depth, but also, in the case of scarifiers, about the height of processing (for more details, see above). Anyway, the more depth (height) settings, the wider the choice of the operator, the more accurately he can choose the optimal value for a particular situation.

Rotation speed of the aerator shaft in normal operation.

Manufacturers select the shaft speed in such a way that the device is guaranteed to be able to cope with the tasks for which it is designed. So in most cases, this parameter is more of a reference than practically significant. At the same time, for verticutters (see "Type"), it can also have a practical meaning: lower speed, with the same power, provides higher tractive effort and allows you to better cope with dense soils and thick rhizomes. So for such conditions, it is worth choosing a model with lower revolutions, and for a favorable environment, on the contrary, higher (high revolutions have a positive effect on performance).

The design of the working mechanism provided in the aerator, in other words, the number and types of working elements installed on the shaft. For verticutters (see "Type") such elements are blades, for scarifiers — spring teeth. For combined models, in this case, the design of both working shafts is indicated, for example "14 knives / 20 spring teeth".

The ability to change the height of the aerator handle. This feature makes it possible to adjust the unit to the height of the user in order to ensure comfort and reduce fatigue.

The volume of the petrol engine installed in the corresponding type of aerator (see "Engine type"). Usually, the larger the engine (with the same type of internal combustion engine, see above) — the higher its power and the more fuel it consumes. In general, this parameter is for reference: manufacturers select it in such a way as to provide the necessary practical characteristics (in particular, the same power).

Aerator engine power expressed in horsepower (hp). In the case of aerators, this unit is used only for models with gasoline engines (see "Engine type"). Note that some time ago, the designation of power in horsepower was standard for internal combustion engines, but now watts are increasingly used for this; so hp is used more as a tribute to tradition than as an urgent need, and most often these data are duplicated in watts. However, even if there is no such duplication, some units can be easily converted to others: 1 hp. approximately corresponds to 735 watts. For more information about the value of engine power, see the paragraph of the same name below.

The power of the aerator motor, expressed in watts. Today, the watt is the common unit of power and is used for both electric and petrol models (see "Engine type"). In general, the more powerful the motor, the higher the performance of the unit, the greater the depth of processing and the working width (see above) can be provided in the aerator; however, the consumption of electricity / fuel also directly depends on the power. Therefore, when choosing an engine for their equipment, manufacturers proceed from a reasonable compromise between these properties, and in general, engine power allows you to evaluate the performance of the unit and its suitability for large volumes of work.