Comparison Vitals BUM 52n vs Patriot AE 52D

The diameter of the drive shaft used in the drill (see "Type").

Working tools for motor drills — augers — are produced for a certain diameter of the drive shaft. Simply put, this parameter is, in fact, the size of the seat for the drill; compatibility with one or another auger depends on it. Most modern models use shafts with a diameter of 20 to 25 mm; usually, the larger the diameter of the shaft, the thicker the screw with which the tool is able to work.

The gear ratio of the reduction gear installed in the drill. This parameter indicates how many times the gearbox reduces the rotation speed of the auger relative to the motor shaft. Knowing the gear ratio and the maximum engine speed, you can accurately determine the maximum rotation speed of the auger: for example, for an engine of 8000 rpm and a gearbox with a gear ratio of 40, the maximum rotation speed of the drill will be 8000/40=200 rpm.

In general, a higher gear ratio (for the same power and engine speed) allows to achieve more torque (at the cost of lower drive shaft speed) and allows larger augers to be used. At the same time, do not forget that the actual ability of a power drill to cope with difficult tasks also depends on other characteristics — primarily the mentioned engine speed and power. This must be taken into account when choosing.

Engine power of the motor drill in horsepower. Horsepower is traditionally used to denote the power of internal combustion engines. 1 HP approximately equal to 735 watts.

Power is one of the key parameters for any motor auger: the higher it is, the higher torque can be achieved on the drive shaft, the thicker augers can be used with the unit and the better it is suitable for complex work and “heavy” soils. On the other hand, high power significantly affects the price, dimensions and weight of the engine. Therefore, manufacturers choose this parameter based on the price category and general purpose of the tool.

The most modest engines, about 0.8 – 1.5 hp, are installed in power drills (see "Type") — for such devices, high power is not needed, but light weight and compactness, on the contrary, are critical. For motor drills, indicators are 1.6 – 3 hp. correspond to the entry level, 3 – 5 hp. — medium, and in the most powerful models, motors of 7 – 8 hp are installed, which makes it possible to work with screws with a diameter of half a metre or more. At the same time, note that units of the same power may differ in screw diameter and other performance characteristics.

Engine power of a motor drill in kilowatts. Watts (kilowatts) are a common unit of power, and this unit is also used for gasoline engines along with horsepower (see above).

Power is one of the key parameters for any motor auger: the more powerful the engine, the higher torque can be achieved on the drive shaft, the thicker augers can be used with the unit and the better it is suitable for complex work and “heavy” soils. On the other hand, high power significantly affects the price, dimensions and weight of the engine. Therefore, manufacturers choose this parameter based on the price category and general purpose of the tool.

Indicators of 0.6 – 1.2 kW are typical for the most modest engines, these are mainly equipped with power drills (see "Type"). In entry-level motor drills, more powerful units are used, by 1.2 – 2.2 kW, the average class corresponds to an indicator of 2.3 – 3.7 kW, and in the most solid devices, the power can reach 5.5 – 6 kW. Note that units of the same power may differ in screw diameter and other performance characteristics.

The highest speed that the engine of the motor-drill is capable of is, in fact, the speed of rotation of the shaft with the throttle squeezed out as much as possible.

The difference between idle (see above) and maximum speed determines the operating speed range of the engine. In this case, a faster motor will have less torque than a slower unit with the same power. At the same time, the speed of rotation of the drive shaft (and the torque on it) is affected not only by the engine speed, but also by the gear ratio of the gearbox (see above); this means that the use of appropriate gearboxes can equalize the capabilities of multi-speed motors. Therefore, it is worth comparing motor drills of similar power not by engine speed, but by the speed of rotation of the working shaft.

The volume of the fuel tank installed in the drill.

A larger tank allows you to work longer without refueling, but it significantly affects the weight of the tool. Given the peculiarities of the operation of motor drills, in fact it is easier to take breaks for refueling than to keep a large supply of fuel in the unit itself. Therefore, tank volumes are usually small, only in some high-power models this parameter exceeds 2 liters. At the same time, manufacturers take into account fuel consumption and select tanks in such a way that breaks do not have to be taken too often.

The largest diameter of the drill (auger) or drill with which the tool is able to work, in other words, the maximum diameter of the holes that can be made using a power drill.

The thicker the drill, the more resistance it encounters during operation and the higher the torque must be to overcome this resistance. Therefore, it is impossible to put nozzles of a larger diameter on a motor drill than stated by the manufacturer: at best, the drill simply cannot turn, at worst, a serious overload and an accident are possible.

The highest rotational speed of the drill (auger) or drill that the tool can provide.

Rotational speed and torque are inversely related: higher drill speeds (for the same engine power) correspond to lower torque, and vice versa. This means that of two power drills of the same power, the slower one will be at the same time more "torque", able to better cope with heavy work and thick augers (see "Maximum diameter"). On the other hand, a higher speed allows faster material selection and less time spent on work, so for light loads, faster tools are preferable.

The presence of a working attachment - auger (auger) or drill - is included in the delivery set of the tool.

Purchasing such a set eliminates the need to look for a drill separately, and besides, the standard attachment, by definition, corresponds to the diameter of the drive shaft (see above). The characteristics of the complete drill must be clarified before purchasing, because they may not meet the buyer's requirements. In light of this, some tools are available in two configurations - with and without a drill, which is important to consider when purchasing.

- For the ground. A working attachment of an auger design for performing excavation work - cutting holes, holes, etc. in the soil. The auger is screwed into the ground using the self-tapping principle and with each turn around its axis it cuts off a dense mass of soil. As the tool deepens, a pit with a circular cross-section and smooth walls is formed. Its depth depends on the maximum length of the drill, its width depends on the diameter of the working nozzle.

- For ice. Ice drills are equipped with an auger with sharper blades than those of ground working attachments. As a result, they effectively “bite” into the ice, making holes in it of the required diameter and depth. Ice augers are often used in addition to light motorized augers, which are supposed to be used for winter fishing.