Do-it-yourself air-cooled compressor. How to make a solid compressor with your own hands at home? Features of using the compressor

Then the author used the unit from a truck, it is driven by a three-phase motor of 3 horsepower. An interesting fact is that the system is equipped with forced lubrication of the compressor under pressure, the car pump from the power steering is responsible for this. If you are interested in the project, I propose to study it in more detail!

Materials and tools used

List of materials:
- an old compressor from a truck;
- 3 hp three-phase motor or similar;
- pulleys, belts, wiring, switches, etc.;
- car gas bottle or other similar container;
- sheet steel, profile pipes, corners;
- wheels for garden carts and axle;
- tubes, hoses, fittings, manometer, filters, etc.;
- car power steering pump (author from Audi 80);
- screws, nuts, fum-tape and more;
- mesh (to make a protective shield);
- dye.

List of tools:
- Miter saw;
- Bulgarian;
- welding;
- screwdriver;
- drill;
- vices, wrenches, etc.

Compressor manufacturing process:

Step one. Install wheels on tank
We will install wheels on the tank so that this weighty car can be transported. To do this, we install reliable steel clamps on the tank and tighten them with bolts and nuts. It is to these clamps that we will then attach all the necessary equipment.

When the clamps are installed, we fasten the axle with wheels. As an axle, we use a rectangular profile pipe, to which round axles for wheels are welded. We choose wheels stronger, with steel disks and bearings, since the weight of the device is quite large.

We also need to weld a leg in the front of the machine, it is made from a piece of pipe, to which a sheet steel nickel is welded.

Step two. Equipment frame manufacturing
The compressor, as well as the engine, will be installed on top of the receiver, they will be attached to the clamps. We make the frame from a corner, as well as sheet steel. We drill holes for the compressor and cut the threads, we will statically fasten it to the frame with screws.

As for the engine, it must be able to ride along the frame so that the belt can be tensioned. We drill holes, and then combine them with a grinder to make slotted holes. As a tensioner, we weld an elongated nut to the frame and wrap the bolt. Now, by tightening the bolt, the engine can be moved back and the belt tensioned.

We weld pieces of steel plates to the frame and then install the frame on top of the receiver. A handle can also be welded to the frame so that there is something to take the compressor for, the author welded it from a profile pipe.

Step three. Adapter
There is a hole in the cylinder with a large diameter, here you need to make an adapter, the author made it from sheet steel. We put a piece of paper to the hole and look for a pencil where to drill holes. Well, then it’s a matter of technology, we cut the workpiece, drill holes and weld the pipe. It is very important that the weld be strong and tight.

Step four. Drain and inlet pipe
We drill a hole in the "belly" of the receiver and weld the nut. As a "crane" will use a regular screw. This part is needed in order to drain the condensate from the receiver, which will certainly form there over time.

Step five. Leak test
To check the tightness of the cylinder, the author poured water into it, and then created a pressure of more than 20 bar. If no leaks are detected at this pressure, then the cylinder is assembled very reliably. It is important to inspect all welds and the drain screw, these places should be dry.

Step six. Connecting equipment
Next, we connect a hose from the compressor to the receiver, and also screw a splitter into the cylinder to connect the selective hose, pressure gauge, valve, and so on. We carefully isolate all threaded connections with fum-tape.

Step seven. Lubrication system
The compressor needs forced lubrication, for this we need a small pump. As a pump, the author decided to use a car pump from a power steering, we also need hoses, a pressure gauge and other spare parts. The lubrication circuit has a 3 bar valve, if the oil pressure rises above this value, the excess oil is sent back to the oil reservoir.

Step eight. Protective shield
For a belt drive, you need to make a protective shield so that clothes or something else does not get pulled in there. To do this, we need a grate made of steel or aluminum. We cut it, rot and cook if necessary. Well, then we fasten the grate with screws to the car.

A portable air compressor, quiet, consuming relatively little electricity - this is probably the dream of every owner of a private house, cottage, garage, small business. Well, it is quite possible to make a mobile compressed air installation on your own, for example, by taking part of the equipment of an old household refrigerator. Each refrigeration unit has a built-in compressor. If you remove this part, add equipment, you get an air compressor from a refrigerator compressor,.

Before deciding to implement an idea, it is advisable to determine exactly: is this idea really worth taking on? Let's consider several important aspects of the topic in order to help future designers make the right decision:

not designed for air service.
The performance of compressors in household refrigerators is low.
Refrigeration compressors require special oil to lubricate the mechanism.

From this follow the corresponding conclusions. When working with an air environment, the device will not be able to function for a long time without good cooling.

When the refrigeration compressor works with freon, due to other temperature parameters of the refrigerant, the housing is cooled.

Compression of the air mixture by a refrigeration compressor occurs in completely different temperature conditions, which will lead to an increase in operating temperature by an order of magnitude. Ultimately, without good cooling, the compressor will simply burn out.

A burnt refrigerator compressor as a result of a violation of technological operating modes. The same fate awaits the device, which is supposed to be used in the project, if you do not apply special protective equipment.

The low performance of home refrigeration units is another factor limiting the use of such equipment for producing compressed air.

For example, in order to pump up a 5-liter receiver to a pressure of 5-7 atm., It will take at least 15-20 minutes of operation of the refrigeration unit.

Meanwhile, this volume of air is not enough even to inflate a car wheel in one sitting or paint one wall of a small garage with a spray gun.

Low performance of the refrigerator system is a common thing for such equipment. But for an air compression system, especially with a large flow rate, a high-performance system is already required

Finally, another important factor is compressor oil. To lubricate the mechanism of refrigeration compressors, a special freon oil is used, the properties of which change dramatically in contact with air.

If you do not change the oil to another type of lubricant that is loyal in structure to air, after a certain time the compressor mechanism will simply “close” due to the rapid wear of parts.

DIY construction

So, if, despite all the noted nuances, a decision is made to assemble from the refrigerator, you can proceed directly to action.

Approximately such a design should be obtained as a result of the implementation of the conceived idea. In appearance, there are no complaints. The device looks more than flawless and quite impressive

The first step is to collect all the necessary details of the project equipment:

Air receiver.
Oil separator.
Differential pressure switch.
Copper tube.
Inlet air filter.
Shut-off control and control valves.

For an air receiver, a compressed air cylinder from a KAMAZ vehicle is optimally suited. The five-liter container has overall dimensions acceptable for the domestic environment and meets the requirements for pressure vessels.

A home compressor made from a refrigerator is best equipped with one of the cylinders that are used on KAMAZ truck tractors. These vessels comply with Rostekhnadzor standards

Design option of the oil separator, which is recommended for use as part of the installation. For reliable operation of the system, high-quality separation of oil from air is required.

A differential pressure switch (for example, from the PT series) is used from among those used in industrial refrigeration plants.

A sufficient amount of copper tube is available in the design of the condenser of a domestic refrigerator. In diameter, it fits the outlet pipe of the refrigerator compressor.

The air filter at the compressor inlet is easy to make from any suitable plastic container by placing an ordinary foam rubber sponge inside. Shut-off control and control valves - valves, check valve, pressure gauges - can be bought at the store.

Assembly of the air unit

An air receiver (for example, an air tank from a KAMAZ vehicle) is mounted on a chassis made of a metal corner. Additionally, it is recommended to install a pair of wheels on the chassis for ease of movement, a supporting “leg” and a handle.

A platform for installing a refrigerator compressor and a bracket for mounting a differential pressure switch are fixed above the upper area of \u200b\u200bthe cylinder. An oil separator is fixed to the side of the receiver, through a clamp and an outlet fitting.

Hand made oil separator. For fastening, one clamp with a bracket was used on the left side of the separator, and the right side is attached to the fitting of the inlet pipe of the receiver

An air filter must be installed on the inlet pipe of the refrigerator compressor. The presence of an air filter is required to reduce the entry of foreign particles present in the air into the system.

It is easy to make an air filter from any plastic container by attaching it through an angled threaded transition to the inlet pipe.

Air filter at the unit inlet. It is easy to make one with your own hands from a suitable plastic container. Foam sponge inside the filter housing

The outlet pipe of the compressor is connected through a compensatory copper tube-heat exchanger with the inlet fitting of the separator (oil separator). The outlet branch pipe of the separator is connected to the receiver through an angle adapter.

A tee and (compressed air outlet) is installed at the receiver outlet. Through the branches of the tee, the outlet of the receiver is additionally communicated by copper tubes with a differential relay and a pressure gauge. There is also a safety valve.

Electrical part and principle of operation

The electrical circuit diagram actually remains intact, with the exception of minor changes. That is, the compressor from the refrigerator, as it was powered from the AC mains through the starting relay, so this option is left unchanged.

Another question is that it is possible to modernize the circuit somewhat. For example, supplement it with a switch installed on the body of the assembled installation. Still, this option is more convenient than periodically plugging and unplugging the plug from the outlet each time the device is used in practice.

This design does not have a separate power switch. The compressor is connected to the network with a two-wire cord with a plug through the contact group of the pressure switch

Also, the circuit for supplying voltage to the compressor must be configured taking into account the inclusion of the contact group of the differential pressure switch.

Due to this configuration, the device will turn off immediately after reaching the set air pressure limit. Here, in fact, that's all. The air compressor from the refrigerator can be considered done.

Some notes on the project

A fire extinguisher for a receiver for a home compressed air unit must be selected taking into account a three-fold pressure margin. Powder OT bottle is not the best choice

Often, fire extinguisher cylinders are used as a receiver for home-made projects. Meanwhile, the containers of powder fire extinguishers have a low limit of the maximum allowable working pressure (8-12 atm.).

In addition, such vessels are subject to mandatory examination after a certain period of time in the relevant authorities. If you still take a fire extinguisher vessel under the receiver, then vessels from under carbon dioxide systems can be considered an acceptable option.

Finally, the most important point. Such structures, in fact, should be registered with the Rostekhnadzor authorities, since the assembly contains a vessel operating at a pressure of more than 0.07 MPa (the operating pressure of the installation is 10 atm.).

Owners of unregistered home-made air compressors may well be held liable (administrative and even criminal), as soon as something extraordinary happens during the operation of the equipment with a threat to human life and health.

So it’s worth thinking a thousand times before trying to assemble an air compressor from a refrigerator compressor with your own hands.

The practice of assembling a compressed air installation

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In the garage of a car enthusiast, you can find many useful and not so useful tools. In addition to the usual set, an air compressor will also be useful. It is suitable for car painting, tire inflation, air supply for pneumatic tool operation. Let's see how to make a car with your own hands. We will also find out how it is arranged and on what principle it works.

Compressed air to help the car enthusiast

Air compressors are quite useful in workshops and garages. There is always a task for these devices. This can be banal cleaning, cleaning from dust that has formed after grinding, or creating air pressure for the operation of various air tools. Most compressors are used for painting. This imposes some requirements on the device.

Air flow and spray painting

For work with paint, the air flow must be as uniform as possible. Also, the compressed air stream must not contain water particles, oil impurities or other oil products. The presence of suspended and solid particles is unacceptable in the flow.

Sometimes when painting you can see defects. Often this is graininess on a freshly applied coat of paint. This happens due to the fact that there were foreign particles in the stream. If paint streaks or dull spots are observed, then this is a sign of uneven supply of paint, enamel or varnish.

Branded or homemade?

What is the difference between a proprietary compressor? Its characteristics are ideal for working with an airbrush or spray gun, but factory products cost serious money. If the device is needed infrequently, then you can save a little and make a unit that will not be inferior to factory models.

The principle of operation of the compressor

Both professional and self-made devices work on the same principle. In a container for storing compressed air, which is called a receiver, an excess pressure level is created. The air itself can be blown into the receiver both automatically and manually.

If you work in manual mode, then it is certainly very cheap in finance, but it will require serious energy costs. You also need to constantly monitor this process. After such work, it is unlikely that you will want to do anything else.

If you use the mechanisms for pumping air, then this will facilitate the process. There are no drawbacks here, you just need to change the oil in the air pump, depending on the regulations.

Further, the compressed air flow passes through the outlet valve of the compressor or in this case the receiver and is directly supplied either to the airbrush, or to the car chamber, or to the pneumatic tool. In general, the principle is very simple, and therefore the simplest working model can be built in a couple of minutes.

Homemade compressor

Let's look at how to make the simplest compressor for painting a car with your own hands. As one of the options, we will try to make a device for painting work from a car chamber. To create, we need a receiver, a supercharger, a spool from a damaged camera, a repair kit, an awl. When everything you need is assembled and prepared for work, you can start assembling.

At the assembly stage, you need to check the tightness of the chamber. To do this, you can use a car pump. Every motorist knows how to do it. If the rubber holds the air pumped into it, you can proceed to the next step.

If air leaks are found, then you can use a repair kit or vulcanize the hole with raw rubber.

At the next stage, in the so-called receiver, it is required to make holes for another spool. It will be the outlet valve. This fitting can be glued using the same pre-stocked repair kit. This valve is connected to the airbrush. The nipple must be unscrewed from the fitting. The compressor circuit provides for the free passage of air. We will not unscrew the nipple in the main spool. He will keep the pressure.

Then, by the method of scientific poke, we will try to determine the required pressure level in our receiver. For this, a spray gun is used. If the paint lays down evenly, without jerks, streaks or anything else, then everything is done correctly. It is desirable to control the amount of excess pressure in the receiver. When you press the airbrush button, the level should not jump.

As you can see, this is the most primitive compressor for painting a car with your own hands. Now you can create masterpieces or just repaint the body.

It is not difficult to assemble this unit, and its usefulness can be seen during various repairs. If you have used for painting before, then you will definitely be able to appreciate all the advantages.

Just remember that in no case should liquid, dust or anything else get into the spray gun and into the chamber. In the event of a violation, dust or moisture will mix with the paint, and the work will have to be redone. Then no adjustment of the spray gun will help. It will be more convenient if our camera is fixed on something. This will prevent her from moving across the floor.

This model works great, and it is already quite usable. But even better, with small changes, make the injection system automatic. Next, we will learn how to make the compressor more serious.

Semi-professional equipment

Professionals say that such handicraft equipment has a huge resource and service life, unlike factory models of foreign brands and domestic manufacturers. But this is understandable, because, knowing the scheme of work, if any part fails, it can be easily replaced. Let's see how to make a compressor that can be used professionally.

What is needed for assembly?

So. Here you will need readily available spare parts for the compressor. This is a pressure gauge, as well as a gearbox with a filter. You also need a relay to control the pressure in the chamber, a fuel filter from a car, a water quad with a ¾ internal thread. In addition, you should pick up threaded adapters, car clamps, a motor, a receiver tank, 10w40 oil, a toggle switch for 220 V, brass pipes, and oil-resistant rubber hoses. These compressor parts can easily be found in the garage.

Thick wood will be used as the basis for the unit. You will also need a syringe from the nearest pharmacy, anti-corrosion liquid, fasteners, sealants and FUM tape, paint, a needle file, wheels from an office chair and a filter from the car power system.

So, knowing the principle of operation of the compressor, it's time to start building. Let's start with the blower.

Engine as supercharger

We will use a compressor from old refrigerators as a motor. Often it already has a built-in starting relay, which in our case is very convenient. This will automatically maintain the desired pressure in the receiver chamber. It is better to use a motor from old Soviet cooling units. They have higher performance compared to imported products.

Preparatory procedures

Feel free to get the executive part out of your old refrigerator. Naturally, you need to clean the part, because over the years the block has managed to acquire centuries of dust, and also, possibly, to rust. After cleaning, you can treat the body with a rust converter to save the block from corrosion. So, the preparation for painting is done.

Change the lubricant in the actuating unit. It is rare that a refrigerator received service according to the regulations. This system is almost completely isolated from environmental influences. Semi-synthetic is suitable for changing the oil. It is no worse than specialized compressor fluids.

Inlet, outlet and oil change

Must have tubes. Two of them are open, one is soldered. Open tubes are used for air inlet and outlet. To find out which handset is the input and which is the output, you can briefly turn on the power. Next, remember which of the tubes releases air.

The refrigerator compressor circuit says that the lubricant needs to be changed through a sealed tube. You should very carefully cut off the end of the tube with a needle file. It is necessary to saw so that the chips do not get inside. Next, the tip must be broken off and drained into some jar of old grease. Then, using a pharmacy syringe, fill in more lubricant than poured out.

In order for the unit to work properly, the lubrication tube must be sealed. A screw of a suitable diameter will help us with this. It must be wrapped with a pre-prepared FUM tape and screwed into a long-suffering pipe.

Next, attach this device to the board using the prepared fasteners. The electronic part is very sensitive to position. Therefore, the top cover of the relay is marked with an arrow. The operating modes will only switch if the setting is correct.

Choosing a container for the receiver

As practice shows, it works best for painting if a used fire extinguisher is used as an air container. These cylinders are good because they contain the necessary margin of safety. In addition, the fire extinguisher is designed for. This choice is also good because various attachments can be placed on the cylinder body. Take, for example, a metal 10-liter cylinder from OU-10. It holds a pressure of 15 MPa and has high strength.

Fire extinguisher preparation

Immediately boldly twist the lock-starter, we will not need it. And you need to screw the adapter into place, having previously wound the FUM tape onto the thread. If the body is rusted, you need to treat the rust with either chemistry or sandpaper.

Outside, in the fight against corrosion, everything is very, very simple. What about corrosion inside? Pour the cleaner into the bottle, and then you need to mix the product very well. Next, screw the cross from the water supply. And don't forget to seal the threaded connections. Now everything is almost ready.

We mount attachments

We almost made a compressor for painting a car with our own hands. To make it convenient to move, the best option is to mount all the nodes and parts on one platform. We have a wooden board. The motor from the refrigerator is already fixed on it, and now you need to place a fire extinguisher-receiver there.

In the plate, it is necessary to make holes for fasteners in advance. The motor from the refrigerator is already fixed with studs and nuts. The fire extinguisher must be placed vertically. To do this, you can use plywood. This will require three sheets.

In the first sheet, cut a hole suitable for the diameter of the balloon. Fix the rest on the plate. Next, fix these plates to the plate along with the sheet with the hole using glue. To make the fire extinguisher conveniently located on the platform, you can make a recess under the bottom. To make our device maneuverable, take out the prepared furniture wheels and screw them onto the platform.

Protection against dust and small debris

Naturally, the equipment must be protected from dust as much as possible. To do this, we will use a car. The filter must be mounted in the air intake.

How to do it? We use a rubber hose. It should tightly compress the autofilter fitting and the compressor inlet pipe from the refrigerator. On the inlet tube, you can not clamp the hose with clamps. There is no high pressure.

Moisture protection

An oil separator must be installed at the outlet. It will not allow liquid or oil particles to get into the system. To do this, you can apply a filter from the diesel power system. The connection is made using the same hose. But here it is already necessary to strengthen the connections with a clamp, because there will be decent pressure at the outlet.

denouement

The diesel filter must be connected to the reducer input. It is necessary to untie the pressure at the inlet and outlet of the refrigeration compressor. To do this, the high pressure outlet of the supercharger must be screwed into the left and right side of the crosspiece.

We fix the pressure gauge

A manometer is fixed at the top entrance of the crosspiece. On it we will perform pressure control. You also need to tighten the adjusting relays. Do not forget that the threads must be sealed.

Relay importance

This device makes it possible to regulate pressure levels over a wide range. It can, if necessary, interrupt the power supply to the refrigeration motor. For these purposes, either PM5 or RDM5 is suitable. Both devices will start the motor if the pressure drops and turn off when it rises. The pressure level is adjusted using the springs on top. So, with the help of a large one we set the minimum levels, and a small one - the maximum limits.

Electricity

To make it all work, we connect the neutral power wire to the relay, and connect the second wire to the refrigeration engine.

Pass the phase wire through the toggle switch to the second contact of the compressor. This will allow you to turn off the power faster. Naturally, after connecting, you need to securely insulate all this.

So we made a compressor for painting a car with our own hands. It remains only to paint, adjust and test it.

Adjustment and first tests

After assembling all this together, you can safely proceed to the first tests. Connect an actuator to the output of the unit. Then plug the cord into the outlet, set the relay to the very minimum and turn on the toggle switch. Look at the pressure gauge. If you are convinced that the relay turns off the motor, you can check the tightness. To do this, use the old-fashioned way with soap.

If everything is fine, then bleed the air from the receiver. When the pressure drops, the relay should start the motor. If everything works, then painting with an airbrush will no longer cause difficulties.

First samples

To test the unit in operation, any unnecessary part will do. There is no need for any surface preparation. It is important to determine the working pressure by trial and error. With the help of experiments, determine the figure at which the pressure is enough for a complete painting without frequent switching on of the motor.

As you can see, it is quite easy to make for painting. This unit can already be fully used for professional activities. The costs will definitely pay off soon. The compressor is needed not only for painting work. It has a very wide range of applications. A semi-automatic system will allow you not to be distracted from work.

Spray guns

In addition to the compressor, airbrushes will also be needed for painting work. To do this, you need to purchase a pneumatic model. A properly selected airbrush will allow you to successfully carry out work. The tool should be selected based on the characteristics of the compressor.

An airbrush for a car should be correctly selected in accordance with the working pressure. If the choice is wrong, the pressure will drop too quickly, and the quality of work will be very low. There are several technologies that are used in this tool. They need to be selected based on the task. For example, modern LVLP technology makes it possible to use paint very economically with a small air consumption, and the surface will be of high quality.

How to set up the spray gun?

High-quality painting is possible only with properly configured equipment. The spray gun setting allows you to change the width of the torch, air pressure, as well as the paint supply.

With the width of the torch, everything is very clear. Maximum width - maximum speed, even overlap. For touch-ups, the flame is reduced, but the air supply is also reduced.

Adjusting the flow of paint is also easy. Many experts open it to the maximum. But the air supply can be problematic. For the correct setting, you will need a compressor, instructions for a specific spray gun. It is necessary to use a sheet of drawing paper and direct a jet from the spray gun at it. If the flame is in the shape of a figure eight, reduce the pressure. If the paint is dripping, add it. Find the best position.

I have been dreaming of buying a compressor for two years now. A very useful device for a wide variety of jobs in the garage: pumping wheels, painting with a gun, blowing engine parts, and so on. On average, a simple compressor costs 10 thousand rubles, a home-made one cost 300 rubles, plus a bunch of rubbish that was lying around at home. An old compressor from a refrigerator, a gas cylinder, a pressure gauge 10 BAR, angles and tees from brass, plugs for them, metal nipples with threads from moped chambers, clamps, washers.

For manufacturing, I used a compressor from a cylindrical refrigerator installed horizontally. It has a capacity of 10 l / min, which is very small compared to industrial ones, but I don’t need to, say, bleed air at a low pressure of 3 Bar for 5-10 seconds, when the pressure in the receiver (I’ll talk about it later) is 8-9 Bar.

For the receiver, I take a 50l gas cylinder. He drained all the gasoline from him ahead of time. I tried to spin the crane, but no matter what methods I used, the crane did not succumb.

Since the cylinder valve has a left-hand thread, I decided to make a 3/4-inch adapter with a right-hand thread. I took a high pressure hose and two adapters from 3/4 to 10mm with left and right threads. It turned out such an adapter

I assembled a simple splitter from tees and corners and made a trial inclusion.

In 45 minutes, the cylinder gained pressure of almost 9 bar, with a receiver volume of 50L, this is approximately 430L of air

He scored a couple of times, and then lowered the cylinder upside down to remove the remnants of gas and gasoline, after which he set about a thorough assembly. The position of the cylinder is horizontal, I welded the compressor mount on top and installed all the wiring with a pressure gauge. I fixed the scheme on clips mounted on nails welded to the cylinder by welding. The compressor with the circuit was connected with a hose, fastened to the clamps

I drilled a hole in the plug, inserted a nipple into it and put a rubber gasket on top. I clamped the plug onto the tap, two tees in a row to the tap: one outlet to the receiver, the other to the pressure gauge. Then I wound a corner, a coarse filter to the corner, a coupling to the filter and the same plug as on the other side.

The filter had to be installed so that the oil that the compressor squeezes out settles and does not fall into the receiver and tubes.

It remains the case for small, weld the legs and paint everything in one color. One leg in front, two in back. All legs are the remains of a corner

I didn’t set the machine to turn off until there is money to buy it. For the same reason, I did not install a pressure regulator. How will the money finish, but for now enough and so.

Related video from YouToBe

I won't paint, I'm lazy.
With uv. Admin check

To buy or not to buy? That's the question. But for those who have an old faulty refrigerator with a working compressor, this question disappears - of course, make a compressor for painting using the available materials yourself!

Self-assembly of the compressor is not as complicated as it seems at first glance, especially if you know the principle of its operation. To assemble the compressor, you will need an engine driving air into a container where the same air will be under pressure. The mechanism is designed so that excess air, due to which the pressure in the tank may exceed the necessary one, exits through a special bleed valve. This is necessary so that during the process of painting the car (or whatever else is needed), the paint lays evenly on the entire surface, and this effect can be achieved only when there is constant pressure in the sprayer.

The compressor can be used in a wide variety of areas - for tire inflation, airbrushing, painting spare parts and so on. With the necessary tools and certain knowledge, it is quite possible to independently manufacture this unit based on a conventional refrigerator. A homemade compressor gives about 7 atmospheres, which is enough for an ordinary garage workshop. The refrigerator compressor will turn out to be quite quiet and, most importantly, cheap at cost.

Which is better - homemade or purchased?

In total, there are several main differences between them:

The design of the factory compressor contains an electric motor that transmits torque to the working chamber through a belt drive. As for the homemade compressor, it consists of a housing and the engine itself, without belts.
In the factory version, automatic pressure relief systems, inlet and outlet filters, pressure gauges, etc. are already installed. In the compressor from the refrigerator, you will have to install the adjusting equipment yourself, taking into account all the features.
Despite the fact that most factory compressors are equipped with automatic systems, this feature is not implemented in some budget models. In other words, these units will have to be turned off on their own, marking the time by the clock. Homemade compressors are mainly equipped with a protective relay that turns off the engine when there is a risk of overheating.
In some factory models, any lubrication may be completely absent. Of course they are small, but there are no various exhausts. This circumstance is very important, especially if the spray gun behaves rather capriciously, not tolerating various impurities. As for homemade compressors, there is plenty of oil.
The main feature of a homemade compressor is that it works very quietly, especially if you put all the tubes on it correctly, observing tightness. As for factory compressors, they behave more noisily, so its use is only possible outside the home.
The cost of manufacturing a home-made compressor is very low, because the main components are taken from old technology, and the control equipment will cost a maximum of 1000 rubles.
It is not possible to make any technical changes to the factory compressor. In other words, if the unit is not powerful enough, then it can only be used as a tire inflation pump, no more. Homemade options are good because you can add some details to them, for example, a large receiver, so you can significantly increase the power of the device.

As practice shows, a home-made compressor for painting a car breaks down much less frequently than its foreign and domestic factory counterparts. On the Internet you can find many instructions for building compressors with your own hands. So let's discuss a few options that can help in this matter.

Schemes for the manufacture of a homemade compressor

Here are several options for device assembly schemes - choose which one is best suited for your purposes:

Compressor Assembly Parts

pressure switch;
manometer;
gearbox with oil separator;
oil separator filter;
adapters;
cross;
fitting and nut;
clutch;
nipple;
a tube;
car clamps;
receiver;
nuts, studs, washers;
furniture wheels;
motor oil;
toggle switch;
plug and cord;
fuel filter;
plywood panels (chipboard);
refrigerator compressor;
oil and petrol resistant hose, screws, Epoxylin, sealant, paint, fum tape, rust remover and other small things.

In my options, I checked several different control valves. After several attempts, I ordered a RUCK14IAMSV check valve, it does not buzz and can be perfect for building a compressor from refrigeration units. You also need to buy a safety valve (MINI SVM14-12). Take a tank from a powder fire extinguisher 16 kg. The pressure in the tank is 9.5 bar and the shelf life is 2 months.

Important: pay attention to which oil to fill in - synthetics are very poorly combined with regular ones, so you do not need to pour everything that is horrible.

An oil separator must be installed between the compressor and the tank.
Oil should be added through the third brazed tube.
It is best to solder the connector and screw it in with a screw or a metal plug.
Install a dehydrator, it also captures oil.

Due to the sudden failure of the refrigerator, he became the owner of an efficient 110 watt unit. Of course it can be converted into a compressor. There is an automotive airbrush, which was previously used with a 12-watt compressor, as well as a high-power compressor. These devices are noisy and short-lived. So I had to make my own.

Compressor assembly instructions

It is important to properly dismantle the compressor in order not to damage it. First, use the wire cutters to cut through the tubes coming out of the engine leading to the grille. Next, the wires from the relay are cut off, but their length should remain approximately 20 cm. Before unscrewing the compressor, it is necessary to make a mark on the relay cover.

After the compressor blower circuit from the refrigerator is broken, the spindle will be exposed to the atmosphere, which will lead to the loss of its properties. If the factory oil is not replaced in the supercharger, its pistons will quickly wear out, as a result of which the engine will fail. Therefore, it is recommended to first replace it with a motor semi-synthetic one. like from a car.

In addition to the outlet and inlet tubes, the compressor from a conventional refrigerator is equipped with a third tube with a sealed end. In order to use it for painting cars in the future, it is necessary to remove the clogged part. To do this, using a hacksaw for metal, you should make a neat incision around the tube, but without sawing it to the end, and then break off the filed piece. It is important that metal chips do not get inside.

The remaining pipe must be flared and drained of the old oil, then pour semi-synthetics into it in the same amount. After that, the pipe is clogged with a screw wrapped in fum tape.

The fire extinguisher body will go great for the receiver. It is important that it be cast, seamless and have a volume of 10 liters or more. Before using it, you need to inspect the inside of the fire extinguisher for corrosion. A flashlight is used for inspection. If corrosion is still present, it must be removed with a special liquid.

Stages of assembly work

To make a compressor from the refrigerator means to follow a simple sequence of steps:

Take pliers, a spanner wrench for 12, 2 screwdrivers - for plus and minus. At the bottom of the back panel, bite with pliers the tubes connecting the compressor to the cooling system. Unscrew the start relay, after marking the upper and lower sides on it. Disconnect the relay from the plug. We take all the fasteners with us.
Function test: connect the relay back, provide air access to the compressor through the pipes, connect to the network. If everything is done correctly, then the device works. Air will enter one tube and exit the other. Label these tubes.
Attach the compressor with self-tapping screws to a wooden board.
We take an old fire extinguisher, 1 hose 600 mm long, 2 others - 100 mm, fuel filter, clamps, pressure gauge, sealant. We already have a drill, screwdriver, pliers.
If there is no fire extinguisher, then we will make a plastic container. To do this, you need to take a container with a volume of more than 3 liters. Make 2 holes. Insert the inlet tube into 1 hole at a distance of 2 cm from the bottom of the container. We lower the outlet pipeline 10 cm deep. It is impossible to install a pressure gauge on a plastic tank.
If there is an iron tank, then the tubes can be fixed by welding. We install a pressure gauge on the iron receiver.
We fasten the receiver and compressor together.
Put a filter on a hose 10 cm long, attach the free end of the tube to the inlet of the designed apparatus. Connect the receiver inlet to the compressor outlet with another hose. We fix the docking points with clamps. A diesel filter is attached to the last hose, and its free end is inserted into the outlet of the receiver. Equipment can be put on the remaining end of the tube, if necessary, so that airbrushing and painting become available.

The second version of the step-by-step instructions:

We drill a special hole for the adapter to be fixed. You can choose different methods, for example, the most affordable is cold welding (using Epoxylin).
We carefully clean the bottom of the receiver from dirt - plaque and rust. This is necessary in order for Epoxylin to adhere well to the surface for strong bonding. And, of course, so that the paint does not get dirty and does not stray into lumps with debris. This can be achieved by cleaning the bottom of the fire extinguisher to a metallic sheen with a rotary-circular motion with sandpaper.
We fix the adapter, clamping it on the front side with a nut, and give time to harden Epoxylin according to the instructions.
We turn to the base for the compressor, for which you need to get three wooden boards or a piece of plywood measuring 30 by 30 cm. For the convenience of further moving our device to the base, you can screw mobile wheels for furniture. We do not specifically describe the dimensions of the holes and other trifles, since this will all be purely individual, as it depends on the material chosen, the type of compressor, and so on.
We drill holes for the compressor and studs and mount them. The studs are secured with nuts and washers.
We put on the breath of the compressor an automobile filter with a special paper core. This will help prevent dust and other small contaminants from getting inside the compressor.
Next, let's take a look at the electrical. To make our home-made compressor for painting a car convenient to use, we equip it with a pressure switch (for example, PM5 or RDM5), as well as a shutdown toggle switch. The first device, a pressure switch, is necessary for us in order to turn off the compressor in the process of pumping air into the receiver, when the pressure reaches the allowable maximum, and vice versa, turn it on when the pressure drops below the allowable minimum. You can set the value of the maximum and minimum pressures directly on the relay using springs, with the large spring responsible for the minimum pressure (and the corresponding activation of the compressor), and the small one for the difference between the maximum and minimum pressure values.
Take a closer look and you will see 2 contacts on the relay, designed specifically for connecting it to the network. Since such relays were originally used in the water supply system, we will slightly change its purpose and connection features. Our task is to connect the first contact to the network, and the second to the compressor.
We put the general shutdown toggle switch on the gap between the pressure switch and the 220V network. This will help to de-energize the entire installation, so as not to constantly run to turn it on and off.
We paint the receiver and proceed to the final assembly.
We screw the nut with the fitting onto the filter-oil-moisture separator.
We take the hose and put it on the fitting with one end, and pull it on the compressor tube with the other and clamp it all with clamps. To do this, we take a reinforced, oil-resistant hose. Each threaded connection should be sealed with fum-tape.
We fasten the filter to the bottom of the receiver and treat the silicone joint with sealant.
We fasten the cast-iron cover, but pre-treat its threaded connection with the same sealant. To improve the seal, you can put a rubber gasket under the cover.
A tube must be screwed onto the lid, the thread of which should be a quarter inch, and a crosspiece must be screwed onto it.

Installation of device parts

For ease of storage and movement, it is best to arrange all compressor parts compactly on one base. We will use a wooden board as a basis, on which we securely fix the engine - supercharger and fire extinguisher body.

We fix the compressor engine with threaded studs threaded into pre-drilled holes and nuts with washers. We place the receiver vertically, using three sheets of plywood for fixing, in one of which we cut a hole for the cylinder.

The other two, with the help of self-tapping screws, are attached to the carrier board and glued to the sheet holding the receiver. Under the bottom of the receiver, at the base, we hollow out a recess corresponding in size. For maneuverability, we fasten wheels from furniture fittings to our base. Next, we perform the following operations:

We provide protection for our system from dust and coarse particles, for which, as an air intake, we use a coarse fuel filter for gasoline engines. For this purpose, we use a rubber hose that tightly compresses the filter fitting and the inlet tube of the supercharger. At the compressor inlet, low pressure and strengthening of contact with automotive clamps is not required. Thus, we made an inlet filter for the compressor with our own hands.

An oil separator should be installed at the compressor outlet to prevent liquid particles from passing through. As this protection element, we use a filter in the diesel engine power system. We connect it to the supercharger using an oil-resistant hose. Since the pressure at the compressor outlet is increased, here and everywhere below, to strengthen the contact, we use automobile clamps with fasteners tightened with a screw.

The oil and moisture separator is connected to the input of the gearbox. We need a reducer to untie the pressure receiver and the outlet of the supercharger. We screw its high-pressure outlet into the water crosspiece on the left or right.

We fasten a pressure gauge from the opposite entrance of the quadruple, using it we will control the pressure of compressed air in the cylinder. We screw the adjusting relay on top of the cross. We seal all connections with fum tape and sealant.

The relay will allow you to set a wide range of pressure levels in the receiver, timely interrupting the power supply circuit of the supercharger. As an actuator, you can choose PM5 or RDM5. These devices will turn on the compressor if the pressure of compressed air in the receiver drops below the set mark, and turn it off when the specified range is exceeded. The required pressure is set on the relay using two springs. A large spring sets the minimum pressure level, and a small one regulates the upper limit, setting the compressor shutdown limit. RDM5 and RM5 were originally produced for use in the water supply network and are electrically passive, that is, they are ordinary switches with two contacts. We connect one contact to the zero of the 220 V network, and the second to the supercharger.

We connect the phase wire of the network through the toggle switch to the second network input of the compressor. The introduction of a toggle switch into the electrical circuit allows you to quickly turn off the system from power without running to the outlet every time. All electrical connections are soldered and carefully insulated.

Compressor testing and tuning

Now it remains only to paint the entire compressor and proceed to field tests.

Having assembled the structure, you should check its performance. We connect an airbrush or a tire inflation gun to the compressor outlet. After that, with the toggle switch off, turn on the plug in the network. We set the control switch to the minimum pressure and then apply power to the supercharger. The pressure created in the receiver is controlled by a pressure gauge. After making sure that when a certain level is reached, the relay turns off the engine, we check the tightness of the air ducts and connections. This is easy to do with soapy water.

After making sure that the compressed air does not leave the system, we bleed it from the receiver chamber. As soon as the pressure in the cylinder drops below the set mark, the relay should work and start the compressor. If everything is functioning properly, you can try to paint some unnecessary detail. Preliminary work on preparing the surface for applying enamel is not required here - it is important for us to develop skills and determine how much pressure is required to paint the product. Experimentally, we determine the value in atmospheres at which excess pressure is enough to paint the entire part with a uniform layer with a minimum amount of blower operation.

Adjustment and testing

The main test of a homemade compressor is to determine the possibility of effectively regulating the pressure that is created in the assembled system. The easiest way to do this is to test paint any surface. In this case, the following is sequentially performed:

Set the relay to 4 ... 5 atmospheres.
Connect the compressor to the network.
The pressure gauge monitors the stability of the parameter. If the relay is operable, then when the pressure is exceeded, it will turn off the compressor, otherwise open the relief valve and immediately turn off the unit.
Check the system for the absence of spontaneous bleeding of the energy carrier, for which you can use a regular soap solution.
When the pressure drops to a level below the minimum allowable, the relay should automatically turn on the compressor.
After painting any surface, it is necessary to check the quality of the paint applied to it - during an external examination, traces of moisture, foreign particles and dirt should not be detected. If such defects still occur, you should additionally check the operation of the output filter - oil and moisture separator.

Video instruction for the compressor

The work of the assembled unit will be long and reliable if it is periodically carried out routine maintenance. It comes down to replacing the inlet filters, periodically blowing out all the air lines, as well as changing the oil in the compressor.

It is undesirable to load the compressor by more than 75% of its capacity. But it is quite difficult to understand where the line is, which cannot be crossed, to predict what pressure the compressor will show. It depends on when the refrigerator was released, what brand it is. On older models, this figure will be better. Then, for comfortable high-quality work, you only need to replace the consumable filters.

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