The bulk of the motor manufacturers is supplemented with their own production screws. Such a solution looks expedient, since the development of a rowing vehicle in accordance with the parameters of the engine makes it possible to transform the power into a high, proportional speed of movement. However, it is often necessary to choose a propeller rowing separately. Let's try to understand this issue.
Materials of manufacture
Boating propellers made of plastic are very common in the market today. Such options differ primarily in budgetary value. It is obvious that the drawbacks here are strength, resistance to impact loads, as well as service life.
More reliable in comparison with the previous version is an aluminum propeller. Such a solution is in demand because of its low cost. Among other things, the aluminum propeller does not lose blades when it strikes the bottom. The latter simply bend without catastrophic consequences.
As for the steel screws that have a stainless coating, this option is the most expensive, but it adds a lot of speed. Since the steel is extremely durable, with accidental contact of the blades with hard surfaces during the movement, it is possible to easily lose the reducer of the boat engine. The latter circumstance is a minus of this decision.
In order to correctly select an effective propeller rowing, it is worthwhile to understand several concepts:
- Diameter of the screw - defines the described circle when moving the blades.
- Slippage - the difference between the actual course of the boat and the index of the propeller pitch. Occurs because of the flow of water from the blades.
- Step is the distance that the swimming device will overcome in one turn of the screw, not taking into account the slip effect.
- Disk ratio is the ratio of the area of the circle described by the screw to the area of its blades.
The most important quality that determines how effective a screw propeller is in operation is the step indicator. Understand what kind of characterization is possible by example. Thus, a step of 10 shows the passage of the floating craft in the course of one complete rotation of the propeller over a distance of about 0.3 m. By purchasing a propeller with a high step index, it is possible to significantly increase the speed of the boat, spending less time to overcome the necessary distances.
The circumference, which is described during rotation, is reflected in the movement parameters. However, manufacturers have long made screws with parameters that match the torque and power ratings of the engines. In most cases, the smaller the diameter of the screw, the higher the pitch and vice versa.
- In the case of reduced speed - reduce the pitch of the screw. Here it is worth taking into account the fact that reducing the figure by 1 inch, will increase the speed by 200. With the increased cycle, it is necessary to perform the above actions with the exact opposite.
- It is recommended to select a screw with an increased disk ratio, which will allow maintaining a stable speed at maximum revs.
- Use a better stainless propeller. The price of products of this category starts from 4000 rubles. Their installation will slightly increase the speed.
Before proceeding directly to the purchase of a boat propeller, it is worthwhile to understand the distinctive features of the model range of an affordable price category. It's no secret that most types of products that are supplied to the domestic market are produced in China. However, here again, there are determining differences in the quality of manufacturing screws by individual factories. A huge role is played by used materials, build quality, the nature of the external coating. It is only natural that these figures differ from budget producers and manufacturers of premium products.