How a propeller works. Air propeller. Benefits and effect on the skin

This short article provides basic information about quadcopter propellers (sometimes referred to as props) and how the pitch, shape, and number of blades affect their performance, thrust, and efficiency.

Basic concepts

Attribute parameters are determined by their length, pitch, area, direction of rotation, as well as the shape and number of blades.

Length and pitch

These parameters are the main ones. The length is understood as the diameter of the disk formed during the rotation of the propeller. Pitch can be defined as the distance a propeller can travel through some solid medium in one full revolution (remember how a common screw enters a board). Other things being equal, the pitch value is determined by the slope (angle of attack) of the quadrocopter blades.

The thrust of the propeller group (VMG) is determined by the amount of air that its propellers are able to move. It is clear that an increase in the length and / or pitch of the propellers while maintaining their rotation speed has a positive effect on thrust, but, unfortunately, it also increases air resistance due to growing turbulence. A larger propeller, or a propeller with a higher pitch angle, will use more energy to turn, resulting in reduced flight time, all other things being equal.

Large, low-pitch propellers are ideal for aerial photography, while small, high-pitch propellers are ideal for racing drones.

Number and shape of blades

The classic option is the presence of a propeller with two blades. However, on the smallest models, propellers with three, four and even five blades are used. It is clear that a multi-blade propeller reduces turbulence by creating a more uniform flow. Moreover, additional blades increase total area propeller, which has a beneficial effect on the lifting force of the quadrocopter. It follows from this that a smaller diameter multi-blade propeller is capable of generating the same lift as a larger classical propeller. Multi-blade propellers make the aircraft more responsive, which is very important when flying in Acro mode. The main disadvantage of such screws is the complexity of manufacturing and centering, as well as a rather high cost.

We advise you to pay attention to the difference in the form of ending details. They come in three types - Normal, Bullnose (BN), Hybrid Bullnose (HBN). Normal propellers have pointed blades at the ends, create less thrust, but contribute to the efficient use of battery power. BN screws with equal diameter have a large area and thrust. The extra weight at the tips of the blades increases the torque and improves the aircraft's yaw-axis sensitivity. Unfortunately, these positive aspects are accompanied by high power consumption and reduced flight time. HBN propellers occupy an intermediate position.

Direction of rotation

Multicopters use two types of motors - CW (clockwise rotation) and CCW (counterclockwise rotation). The scheme of installation of motors depends on the type of aircraft. Several such schemes are shown in the figure.

The direction of rotation of a particular propeller is indicated by the raised edge of its blades.

Material and quality

The most popular are plastic screws. They are characterized by plasticity, low price, wide range and high availability. On the one hand, the flexibility of the blades increases their resistance to damage, on the other hand, it causes balancing problems.

Some firms produce propellers made of carbon fiber. Carbon propellers are quite expensive, but provide the required rigidity and high efficiency without significant weight gain.

An intermediate position is occupied by propellers made of plastic reinforced with carbon fiber. This type of propellers has high rigidity and relatively low cost.

The quality of the screws implies the accuracy of their manufacture. High quality propellers are well balanced and practically do not introduce additional vibration into the operation of the VMG. The best props are produced under the brands GWS, APC and EMP.

Specification

You can find out about the parameters of a particular propeller for a quadrocopter by its encoding. Manufacturers use two types of designations: LLPPxB or LxPxB. Here L is the length, P is the pitch and B is the number of blades. For classic propellers, parameter B is usually not specified.

For example, a 6045 (or 6×4.5) propeller has two blades, is six inches long, and has a 4.5-inch pitch. Another example is a 5" 3-blade 5040x3 (or 5x4x3) propeller having a 4" pitch.

Sometimes the letter R or C (may be absent) is placed at the end of the designation, which determines the direction of rotation. R propellers are mounted on CW engines and C propellers on CCW motors. Occasionally, the abbreviations BN or HBN are added to the designation (see above).

Installation Methods

You can install the propellers on the quadcopter in different ways. Very often, the motor shaft is a simple metal pin that does not have any fixtures for mounting the propeller. In this case, special adapters are used - propsavers and collet clamps.

Propsaver (see photo) is convenient to use for experiments when creating homemade models. It looks like a sleeve, in the side surface of which there are two symmetrical holes with screws installed in them. The device is installed on the shaft, and the screws are tightened. The propeller is also put on the shaft and fixed with two nylon ties or a rubber ring.

A more reliable adapter is a collet clamp. It is a threaded connection with a split cone-shaped sleeve. The collet is put on the shaft, then the clamping sleeve, propeller and washer are installed. The whole structure is fixed with a nut of a special shape - a spinner.

If the rotor of a brushless motor is outside (outrunner class motors), then on its upper surface there are usually several threaded holes for installing various adapters and mounts.

Manufacturers of ready-made quadcopters with brushless motors have a very popular option with self-tightening nuts from by DJI. In such engines, the shaft ends with a thread opposite to the direction of rotation of the rotor.

Propeller balancing

It is safe to say that most propellers, especially cheap ones, cannot be called 100% balanced. Such propellers not only make an annoyingly loud noise, but also introduce additional vibration into the operation of the VMG. Because of this, in particular, the quality of aerial filming is reduced (jelly effect). Worse, the constant vibrations cause additional wear on the motors, bearings and gears, which increases the cost of maintaining the aircraft.

As you can see, we cannot do without the propeller balancing procedure for the quadrocopter. For this you will need:

Screw;
Scotch tape or superglue (can be replaced with nail polish);
Sandpaper;
Special propeller balancer Du-Bro Tru-Spin - one of the best, or Chinese analogues .

First of all, you need to set the balancing device itself so that its axis is strictly horizontal.

The blade is checked for damage, mounted on the axle and slightly deflected in one direction or another. If it does not return to a horizontal position, you need to lighten (sandpaper) a heavier blade or stick a piece of adhesive tape on a lighter one. It is necessary to repeat the procedure until the blades are balanced. Adhesive tape successfully replaces a smear of superglue or varnish.

The axis of the balancing machine turns over - you need to make sure that the propeller maintains balance in this position. Note that all cleaning and gluing must be done on the inner (concave) surfaces of the blades.

The next step is to balance the hub. To do this, the propeller is installed vertically. If it deviates to the right, you need to weight the left side of the hub with glue or varnish and vice versa. We achieve balance, turn the propeller over and make sure that in this position it is also balanced. The procedure is over.

eCalc Calculator

Many creators of unmanned models are familiar with the eCalc on-line calculator, designed to calculate the parameters of the aircraft propeller installation. The multicopter calculator page looks something like this.

At first glance, everything is clear, but there are several nuances that can affect the results of calculations.

First of all, a complete takeoff weight multicopter (with gimbal and camera, if any). If Without Drive is specified, then enter the total weight of the frame, propellers, controller board, gimbal, camera and equipment for FPV flights. Add 10 percent to the mass of wires and get the desired figure.

We enter the number of rotors, their scheme (single or coaxial), the maximum flight altitude and the weather conditions under which it will be carried out (overboard temperature and atmospheric pressure).

The bladed propeller of an aircraft, also known as a propeller or bladed machine, which is driven into rotation by the operation of the engine. With the help of a screw, the torque from the engine is converted into thrust.

The propeller acts as a propeller in aircraft such as airplanes, cyclogyros, gyroplanes, snowmobiles, hovercraft, ekranoplans, as well as helicopters with turboprop and piston engines. For each of these machines, the screw can perform different functions. In airplanes, it is used as a main rotor, which creates thrust, and in helicopters, it provides lift and taxiing.

All aircraft propellers are divided into two main types: propellers with variable and fixed pitch. Depending on the design of the aircraft, propellers can provide either push or pull thrust.

When rotating, the propeller blades capture air and produce its rejection in the opposite direction of flight. A low pressure is created in front of the screw, and a high pressure zone behind. The thrown air acquires a radial and circumferential direction, due to this, part of the energy that is supplied to the propeller is lost. The twist itself air flow reduces the flow of the device. Agricultural aircraft, when working on fields, have poor uniformity in the dispersion of chemicals due to the flow from the propeller. A similar problem has been solved in devices that have a coaxial screw arrangement, in this case compensation occurs with the help of the rear screw, which rotates in the opposite direction. Similar propellers are installed on aircraft such as the An-22, Tu-142 and Tu-95.

Technical parameters of propellers

The most significant characteristics of the propellers, on which the thrust force and the flight itself depend, of course, are the pitch of the propeller and its diameter. Pitch is the distance a propeller can travel by being screwed into the air in one complete revolution. Until the 1930s, screws with constant step rotation. Only in the late 1930s, almost all aircraft were equipped with variable-pitch propellers.

Screw parameters:

The diameter of the propeller circle is the size that the tips of the blades describe when rotating.

The pitch of the screw is the actual distance traveled by the screw in one revolution. This characteristic depends on speed and rpm.

The geometric pitch of the propeller is the distance that the propeller could travel in a solid medium in one revolution. It differs from the tread of the propeller in the air by the sliding of the blades in the air.

The angle of location and installation of the propeller blades is the inclination of the blade section to the real plane of rotation. Due to the presence of twist of the blades, the angle of rotation is measured along the section, in most cases it is 2/3 of the entire length of the blade.

The propeller blades have a front - cutting - and a trailing edge. The cross section of the blades has a wing-type profile. In the profile of the blades there is a chord, which has a relative curvature and thickness. To increase the strength of the propeller blades, a chord is used, which has a thickening towards the propeller root. The section chords are in different planes, since the blade is made twisted.

The propeller pitch is the main characteristic of the propeller, it primarily depends on the angle of the blades. Pitch is measured in units of distance traveled per revolution. The more pitch the propeller makes in one revolution, the more volume is discarded by the blade. In turn, an increase in pitch leads to additional loads on power plant, respectively, the number of revolutions decreases. Modern aircraft have the ability to change the inclination of the blades without stopping the engine.

Advantages and disadvantages of propellers

The efficiency of propellers on modern aircraft reaches 86%, which makes them in demand by the aircraft industry. It should also be noted that turboprops are much more economical than jet aircraft. Nevertheless, the screws have some limitations both in operation and in the constructive plan.

One of these limitations is the “locking effect”, which occurs when the diameter of the screw increases or when the number of revolutions is added, and the thrust, in turn, remains at the same level. This is due to the fact that sections with supersonic or transonic air flows appear on the propeller blades. This effect does not allow aircraft with screws to develop a speed higher than 700 km / h. On the this moment the fastest machine with propellers is the domestic model of the Tu-95 long-range bomber, which can reach speeds of 920 km / h.

Another disadvantage of screws is the high noise level, which is regulated by ICAO world standards. The noise from the screws does not fit into the noise standards.

Modern developments and the future of aircraft propellers

Technology and experience allow designers to overcome some of the noise problems and increase traction beyond the limitations.

Thus, it was possible to bypass the locking effect due to the use of a powerful turboprop engine of the NK-12 type, which transmits power to two coaxial propellers. Their rotation in different directions made it possible to bypass locking and increase traction.

Thin saber-shaped blades are also used on propellers, which have the ability to delay the crisis. This allows you to achieve higher speeds. This type of propellers is installed on the An-70 aircraft.

At the moment, developments are underway to create supersonic propellers. Despite the fact that the design is being carried out for a very long time with considerable cash injections, it has not been possible to achieve a positive result. They have a very complex and precise shape, which greatly complicates the calculations of designers. Some off-the-shelf propellers of the supersonic type have been shown to be very noisy.

Enclosing the propeller in a ring - an impeller - is a promising direction of development, since it reduces the end flow around the blades and the noise level. It also improved security. There are some aircraft with fans that have the same design as the impeller, but are additionally equipped with an airflow direction apparatus. This greatly improves the efficiency of the propeller and the engine.

Pimples can appear at any age, but most often in adolescence. Not every student can afford expensive skin care products. In this case, the line of acne propeller cosmetics comes to the rescue.

This product is aimed at combating rashes, acne, problematic and oily skin, black spots. Even adults sometimes acquire these funds. There are several series, from each you can individually choose the right cosmetics.

General product information

Propeller cosmetics help reduce sebum secretion, narrow pores. They relieve inflammation and soothe irritated skin, fight with various types rashes.

This cosmetic prevents the appearance of new acne, marks and scars after them. The skin looks even, healthy and radiant.

This manufacturer has 5 lines of care products:

Turbo Active with cincidon.
Pore Vacuum to shrink pores and clear blackheads.
Medical Pharm Only with Azelaic Acid.
Estetic Red - matting agents.
Immuno with lactulose and salicylic acid.

Action method

How acne propellers work:

Washing gels remove impurities and sebum.
Tonics and lotions dry out inflammation, tone the skin, and prepare it for the next step.
Mattifying tonic-powders do not allow the skin to shine.
Scrubs smooth the surface of the skin, eliminate black spots and peeling.
Peeling rolls gently exfoliate the skin, remove irregularities.
Means of local action are effective for local problems.
Creams are used to mattify and moisturize the skin.
Cleansing strips effectively push blackheads to the surface.
Tonal creams hide skin imperfections and perfectly mattify.

All products matte the skin, the face no longer looks like an oil pancake. The skin is smooth, fresh, radiant and elastic. Skin care cosmetics do not mask the problem, but eliminate the cause.

Acne propeller - cosmetics line

In each of the five series, you can find the most effective acne remedies. In the right combination with each other, they will help get rid of rashes forever.

Cream sos local action

It is a pure white concentrate. It is applied pointwise to problem areas. The cream eliminates existing rashes, prevents the appearance of new ones, fights scars and acne marks.

The manufacturer promises to fix these problems within 24 hours. Zincidone in the composition dries up inflammation, slows down the production of sebum. It has soothing and antibacterial properties.

Means "3 in 1"

Can be used as a gel, scrub and mask. An all-in-one product that deeply cleanses and exfoliates the skin. Evens out the tone and structure of the skin.

The anti-acne complex with cincidon in the composition reduces the number of harmful bacteria. Mattifies and refreshes the skin.

Azeloin cream

Contains azeloglycine, which reduces the amount of sebum secreted by the skin and normalizes the functioning of the sebaceous glands. Ivan tea extract has an antibacterial effect and relieves inflammation.

The cream contains vitamin E, which acts as an antioxidant. The tool acts on any type of acne, traces and scars from them, helps with rosacea.

Acne cream for daily care

The care cream is designed to narrow enlarged pores. It has a moisturizing effect. Kills harmful bacteria and creates a special barrier that prevents them from penetrating again.

The acids in the cream are aimed at eliminating the cause. They regulate the work of the sebaceous glands. The light structure of the cream allows it to be quickly absorbed. Promotes a feeling of freshness and lightness.

Washing gel with cincidon

Opens pores, pushing dirt, dust and oil out. Gently yet thoroughly cleanses the face. The anti-acne complex with cincidon has an enhanced effect.

Antibacterial gel eliminates acne and oily sheen, normalizes the secretion of sebum. Evens out the skin structure, has a matting effect.

Shower gel

Pimples appear not only on the face, but also on the body. The propeller shower gel cleanses the skin very gently without dehydrating it.

Lactulose and anti-acne complex maintain normal skin moisture and prevent the appearance of acne on the body.

Detox mask

Soft exfoliating action helps to eliminate dead skin cells and excess sebum. The mask leaves the pores clean longer, which reduces the likelihood of acne.

The complex with cincidon has antimicrobial and anti-inflammatory effects. The skin becomes matte, clean and even.

salicylic lotion

Tones the skin, prepares for subsequent care products. Bio salicylate complex destroys germs and reduces redness. Lactulose cleanses and dries the skin.

The lotion helps eliminate existing acne and prevents new breakouts. Forms a protective film that prevents microbes from reaching the skin.

Salicylic suspension Boltushka

Most popular among teenagers. It copes well with acne at this age, eliminates harmful bacteria. It comes in a glass bottle with an applicator.

Restores the structure of the skin, evens it out, makes it smoother. This is facilitated by zinc, lactulose and the bio salicylate complex in the mash.

Spot applicators

These local action products are impregnated with a special hydrogel. The composition acts specifically on the pimple, helps it dissolve faster.

The active ingredients in the composition reduce the number of harmful bacteria, remove inflammation and marks after acne. The tool works gently, does not damage the skin.

Activated charcoal strips

Blackhead Cleansing Strips push impurities to the surface. The dots adhere to the strip and come out completely from the pores.

Licorice extract opens pores. Activated carbon is a natural adsorbent. It grabs the dirt and pulls it out. The pores are clean and empty.

Mode of application

cream sos: Apply to the inflamed areas of the cleansed face with driving movements. Before applying, you can use a tonic for acne. Recommended to do before bed. The longer the cream is on the skin, the sooner the effect will be noticeable.
3 in 1 tool: Apply with massage movements all over the face, leave for a couple of minutes. Make a lather on the face with water and rinse off. Wipe the face with an anti-inflammatory tonic and apply a cream. Apply 1-2 times a week.
Azeloin cream: Apply to clean skin once a day. After 4 weeks, the effect will be noticeable, which will remain with the constant use of the product.
Acne daily cream: Apply daily with massage movements on cleansed and treated with lotion skin of the face. Use until the problem is completely fixed.

Shower gel: Shake into foam on a damp palm, massage your face and rinse with water. Use in the evening, for very oily skin and in the morning. Use tonic and cream.
Shower gel: massage every evening the wet skin of the body with or without a washcloth. Wash off with plenty of running water.
Detox mask: spread over a clean face with a three-millimeter layer. Leave for 8-10 minutes. Wash off with warm water. Use salicylic lotion and acne cream. Can be applied 2-3 times a week.
salicylic lotion: wipe the face with a cotton pad in the morning and evening after washing and before applying the cream.
Chatterbox: wash, use a tonic and apply only on inflamed areas with acne. Shake the bottle before use.
Applicator: remove the film, apply it on the face cleansed and wiped with lotion on the problem area and smooth it out. The procedure is carried out in the evening, leave the applicator until the morning. Repeat as many times as needed for the pimple to disappear.
Nose strips: clean your face, do not wipe the water. The surface of the nose should be wet. With insufficient moisture, the strip will not stick. Remove the strip from the film, stick it on the nose and smooth it out. After 10-20 minutes, remove from the wings of the nose to the center. Use a pore narrower.

Video: How to get rid of rashes in a week

Price

Average price for this cosmetics:

gel for washing with cincidon 120 rubles;
3 in 1 tool costs 160 rubles;
salicylic lotion 70 rubles;
salicylic suspension talker 130 rubles;
acne detox mask 130 rubles;
cream-sos 180 rubles;
cream azeloin 270 rubles;
shower gel 130 rubles;
strips from black dots 150 rubles;
daily cream 140 rub.

Low cost and noticeable efficiency attracts a large number of people.

Photo: Before and after

Acne propeller care products effectively cope with acne, inflammation, black spots, excessive sebum secretion.

Suitable for oily and problematic skin. Spot remedies fight individual acne, with dry skin of the face it is convenient. If you choose the right cosmetics, a good result is guaranteed.

The popular brand "Propeller" offers buyers acne cosmetics. The developments of Russian specialists appealed to people with problematic epidermis.

Innovative products are suitable for the treatment and prevention of acne. Regular use will allow you to put the skin in order, cleanse the epidermis from unaesthetic rashes. Take a closer look at the popular Russian cosmetics "Propeller" for acne!

general information

What is the difference between the products of the company "Folk Crafts?" Who are popular cosmetics suitable for?

Useful information:

gels, creams, lotions, acne strips Propeller can be used not only for young people. The funds are suitable for everyone who suffers from acne, increased greasiness of the epidermis, the presence of open comedones, from enlarged pores;
the composition of the products includes unique components, complexes that actively influence the processes occurring on the surface and in the depths of the epidermis. Among them are Zincidone, ANTI-SEBIUM acids, BIO-salicylate, titanium oxide, active zinc, betaine, octopirox, panthenol, essential oils, and other useful substances;
customers can easily find the product they are interested in in one of the three lines of cosmetics created to deal with a specific problem. Each line contains many innovative products for face and body care.

Note! The manufacturer has included a lot of innovative components in the composition of products that carefully care for the skin. Know-how includes non-toxic silver chloride, squalane, anti-acne components, ZnPCA antibacterial complex.

Benefits and effect on the skin

Many Russians have already used Propeller acne products.

The advantages of active products are many:

a wide selection of cosmetics - from gels, facial cleansers to unique strips, applicators from blackheads;
active influence on problem areas;
presence in the active components, including plant extracts;
no side effects;
the series even contains a moisturizing foundation that does not clog pores;
a noticeable effect appears quickly enough;
products are certified. The quality is confirmed by the "International Association for Quality".

Important! A series of acne is recommended even for pregnant women. Expectant mothers know how often pustules pop up on the face and body due to hormonal imbalance. It is difficult to find a cosmetic hypoallergenic acne remedy that does not harm the baby. Cosmetics "Propeller" will help out even in such a situation.

Action on the skin

Highly active agents:

stop the reproduction of pathogenic microorganisms, harmful propionobacteria;
urea and salicylic acid dry the epidermis;
due to the action of the sulfur-containing complex, the activity of the sebaceous glands gradually decreases.

oily sheen goes away;
with regular use, the pores remain clean, narrow well;
keratolytic activity (exfoliation) of cells is enhanced;
the surface is quickly cleared of dead particles of the epidermis;
the relief and color of the skin improves.

Learn all about treatments folk remedies and modern methods.

Read the page for details about the causes of acne on the temples in women and men.

The main lines of cosmetics "Propeller" for problem skin

The products are divided into three lines. Think about what problem bothers you the most, select cosmetic products from the right line.

"Aerobatics of purity"

Direction:

decrease in the activity of the sebaceous glands;
fight against blackheads and enlarged pores.

acne, various rashes, inflammation is gone;
pores are enlarged;
large black dots remained on the face, worsening the appearance.

"Acne Fighter"

Action on the skin:

rapid removal of inflammation;
active destruction of bacteria.

Result:

dead cells are removed;
pores are cleansed;
the number of rashes decreases;
even persistent acne on the chin gradually disappears.

"Acne care and protection"

The name of the line accurately conveys the effect of cosmetics. For problematic, rash-prone epidermis, a cream with a light texture is recommended:

night;
day;
moisturizing;
tonal.

The compositions are enriched with unique ingredients that prevent the appearance of pimples. The products are suitable for daily use.

Overview of popular tools and instructions for use

Assortment of cosmetics Propeller to combat rashes - more than thirty items. What is not here! Scrubs, creams, lotions, active applicator, face and body gels, foam, a unique 3 in 1 product (mask + scrub + gel), acne talker and many other useful formulations.

Pick up a few items for comprehensive care. The result is sure to come!

Lotion Propeller from blackheads

The product contains active ingredients:

horse chestnut extract;
Eucalyptus oil;
nettle extract;
unique ANTI-SEBIUM acids.

Means:

reduces the greasiness of the epidermis;
cleanses the skin of blackheads, sweat secretions;
normalizes the work of the sebaceous glands;
kills acne causing bacteria.

Result:

clean, fresh skin;
black dots, no oily sheen.

Instruction:

moisten a cotton pad well;
Wipe your face along the massage lines.

Volume - 200 ml. Price - 210 rubles.

Important! Treat your face in the morning and evening. In the heat, remove oily sheen as needed, no more than 3-4 times during the day.

Scrub Propeller

Acne Fighter line. Thick mass with white and blue splashes:

penetrates deep into pores;
actively draws out fat, dirt, removes dead particles of the epidermis;
refreshes, tones.

Instruction:

moisturize your face
gently apply the scrub gel;
wipe the places of accumulation of black dots with light movements;
rinse with plenty of cool water.

Not everyone likes the smell of medicine. The composition cleanses the epidermis well. They don't need to remove their makeup.

Volume - 100 ml. Price - 285 rubles.

nose strips

Choose your option:

classic;
with green tea;
with activated charcoal.

Quantity - 6 pieces in an individual package. Price - 320 rubles.

Innovative product:

opens clogged pores;
dissolves the sebaceous secret, absorbs it;
when removing the strip from the nose, it takes with it all the secretions accumulated in the pores.

Result:

black dots disappear;
pores shrink.

Instruction:

thoroughly clean the nose, moisten with water;
remove the strip, carefully remove the film;
apply to the surface of the nose, smooth, press down well;
after 15–20 minutes, without sudden movements, remove the strip, starting from the wings of the nose;
after the procedure, wash with a gel that narrows the pores, or apply a light fluid.

Acne Cleansing Gel

The concentrated product contains the active ANTI-ACNE complex with cincidone and D-panthenol. Regular use cleanses the skin, gives freshness and health.

Volume - 150 ml. Price - 220 rubles.

Action on the skin:

fights pimples;
reduces inflammation;
kills propionobacteria;
reduces the amount of sebum;
softens;
moisturizes;
prevents the reappearance of ulcers.

Instruction:

wet your face with water;
apply a little gentle jelly-like mass, massage lightly;
wash your face, completely remove the gel.

SOS cream with cincidon

Ideal for local application. The concentrated product on a white basis acts quickly and effectively.

Volume - 50 ml. Price - 290 rubles.

Beneficial features:

prevents the appearance of acne and pimples;
reduces inflammation, redness;
limits the secretion of sebaceous secretion;
dries the epidermis;
heals acne scars.

Instruction:

dot the cream on problem areas;
do not rub the skin, lightly drive in a tender mass;
remove the rest of the cream with a napkin or wash your face.

Advice! Spot treat the affected areas an hour before bedtime. All night the complex with zinc oxide will be active.

Salicylic acne mash

Perfectly copes with acne due to the rich composition:

lactulose prevents the formation of new ulcers;
bio-salicylate from willow bark extract and salicylic acid kills microbes, actively exfoliates unwanted particles;
zinc reduces inflammation, quickly dries, fights post-acne, restores damaged skin.

Instruction:

shake the suspension;
wash, wipe the skin;
distribute the talker on problem areas;
do not treat healthy epidermis.

Volume - 25 ml. Price - 225 rubles.

Important! Make sure that the suspension does not get into the eyes. Check if there are any allergies to individual components.

Foundation for problem skin "Mattifying effect"

The unique formula allows the composition to adapt to the color of your skin. The mass with a light texture contains an antibacterial complex.

Volume - 20 ml. Price - 255 rubles.

Action:

evens out skin tone;
heals the epidermis.

the composition is almost not felt on the face;
lightweight product does not turn into a mask.

Instruction:

cleanse your face;
spread the cream along the massage lines with your fingertips or sponge.

What affects the thrust and speed of the model?
P.S. Many, not knowing this, begin to scribble their comments on the page of the engine or propeller they like, exposing themselves to be greatly humiliated by other members of the club, not because there is a club of evil beginner haters, but because many do not use the search and view at least part of the records, they ask the same question again and again and sitting at the screen with bursting patience waiting for an answer, in the hope that the figure would be as large as possible, all this each time raises and raises the column of patience higher and higher) and from time to time it falls on the next newcomer. So if the answer to your question was not quite adequate and expected by you, then know that someone's patience bar has dropped to 0 marks) and there is no need to rush to the forum or to feedback with a furious desire to write a slander against this scoundrel, whose patience snapped for 101 readings of a similar question, like for 100 previous ones.
Also, you should not ask questions on the topic, the range of the signal and the flight of my Touring 9, how long my battery will last, which engine is better to take, etc. Some questions are just so jammed that I feel like throwing up, and the other is apparently purely rhetorical in order to ask a question just to chat, because no one knows what kind of motor you have when choosing a battery. what kind of screws are used there, no one knows the weight of the model either, and rarely anyone will write it first .. so you have to ask everyone, as if during an interrogation. (So for the future, if someone decides to ask such questions, write everything, for what, what do you want to hang on, in the sense of which aircraft will serve for what purposes, etc.).

In general, enough about this, let's move on to the screws. And so: the screw has 2 designations - the diameter and the pitch of the screw, let's see what it is and what it is for.

Diameter - gives traction...
- Screw pitch - gives speed ...

The pictures in the product descriptions usually have all this information, as in the example below. Also, many sellers write the size of the screw mounting hole
.

The diameter and pitch of the screw are decisive. The pitch of the screw corresponds to the imaginary distance that the screw will move, screwing into an incompressible medium in one revolution. That is, simply put, how much air will take in front of the propeller for 1 full 360º revolution.
The propeller blades, rotating, capture air and discard it in the opposite direction to movement. A low pressure zone is created in front of the screw, and an increased pressure zone behind the screw. The rotation of the propeller blades leads to the fact that the air masses thrown by it acquire circumferential and radial directions, and this consumes part of the energy supplied to the propeller.

By the way, digressing a little from the main topic, the fastest propeller-driven aircraft - the Tu-95 bomber - has top speed 920 km/h Russian turboprop strategic bomber-missile carrier, one of the fastest propeller-driven aircraft, which has become one of the symbols of the Cold War.

Typically, the engine manufacturer indicates the recommended propellers and the characteristics measured by him. (As in the photo below) Next, choose the option you need.
If you want to experiment - choose a certain option from the one recommended by the manufacturer and start playing. Those. , if you need traction, then increase the diameter by an inch and decrease the pitch by an inch. So that the sum of the pitch and diameter remains the same with the recommended manufacturer as on the site http://gazovik.online
If you need speed, increase the pitch by an inch and decrease the diameter by an inch.
For example, a 9 * 6 screw on 3 cans of lipo, the motor (it doesn’t matter which one in this case) pulls 700 g at 7000 rpm, to increase traction we need to select a 10 * 5 screw, and therefore to increase the speed 8 * 7.
...or another example...
The manufacturer recommends an 8x4.3 screw for the motor installed on the model! With this screw, the motor will give out about 240 grams of thrust !!!
Based on the flight weight of the model, you can replace the 8x4.3 propeller with a 7x3.5 propeller!

For the following pros and cons.
1. Thrust will drop to about 200 grams! For a model of 160 grams, and even more so for a coach, this is not scary.
2. The propeller will become much shorter, resulting in easier landings for the model without landing gear. Handy for hand launched gliders.
3. The current drawn by the motor has been greatly reduced, resulting in +2.+3 minutes of flight time.

Therefore:

1. It is necessary to select screws based on the flight weight of the model and based on the manufacturer's recommendations.
2. It is necessary to select screws based on the "type" and model destination
3. Need to pick up screws based on motor parameters(maximum load current, revolutions per volt, etc.)

Conclusions: you need at least 2-3 different screws (a little more and a little less in parameters from those recommended by the manufacturer) to find the most optimal among them to achieve your goal. All this is selected experimentally.

In fact, there are still a lot of important nuances when choosing a motor and a propeller, which I would not advise you to take root in and bother yourself too much, but just take those screws that the motor seller advises you for the best traction, well, if there is the desire to experiment with screws slightly different from those recommended.
But if you still have a desire to climb further into the jungle, then here's another article - a continuation especially for you.

As an option for more accurate and effective work motor, you can measure the voltage with a wattmeter during its operation with different screws, so as not to overload the motor and not go beyond its rated power, so as not to burn the winding in an attempt to squeeze the maximum out of the motor due to unwillingness to replace it with another more suitable one. Those who are interested can see the diagram below.

The meaning is clear, I think, and he is here alone. The screw planted - gave full throttle, measured the thrust, measured the readings of the wattmeter, compared with those that go to technical specifications for this motor, if less than the declared ones it means good, if more then it is bad, for maximum efficiency of the motor, the consumed current should be as close as possible to the nominal in the characteristics, but not exceed it.

And finally, a couple of answers to questions that also sometimes come across.
What influences minimum speed models?
Aircraft are able to fly at low speed due to the low load on the wing, the greater the load, the higher the speed should be so that the plane does not crash to the ground or the wing is larger in area.

Why can't the ends of the screw be cut off?
The screw pitch is not constant: more at the base, and less towards the end.
The manufacturer indicates some average "working", given that the maximum efficiency is considered closer to the end of the blade.
By cutting the screw at the end, we change this indicator - we take a big step ...
Approximately: if you take a 9x6 screw and cut it to an inch, thinking that we get 8x6 - mistakenly, we get 8x7 - that's it.