Creating high-density airflow is possible in several ways. One of the effective ones is a radial type fan or “snail”. It differs from others not only in shape, but also in its operating principle.
Fan device and design
Sometimes an impeller and a power unit are not enough to move air. In conditions of limited space should be used special kind design of exhaust equipment. It has a spiral-shaped body that acts as an air channel. You can make it yourself or purchase a ready-made model.
To form a flow, the design provides a radial impeller. It connects to the power unit. The wheel blades have a curved shape and create a discharged area when moving. Air (or gas) enters it from the inlet pipe. When moving along the spiral body, the speed at the outlet increases.
Depending on the application centrifugal fan snail maybe general purpose, heat-resistant or corrosion-resistant. It is also necessary to take into account the amount of air flow created:
- low pressure. Scope of application – production workshops, household appliances. The air temperature should not exceed +80°C. Mandatory absence of aggressive environments;
- average pressure value. It is part of exhaust equipment for removing or transporting small fraction materials, sawdust, grain;
- high pressure. Forms an air flow into the fuel combustion zone. Installed in many types of boilers.
The direction of movement of the blades is determined by the design, and, in particular, by the location of the outlet pipe. If it is located on the left side, the rotor should rotate clockwise. The number of blades and their curvature are also taken into account.
For powerful models, you need to make a reliable base with your own hands to secure the body. Industrial installation will vibrate strongly, which can lead to its gradual destruction.
Self-production
First of all, you need to decide functional purpose centrifugal fan. If it is necessary for ventilation of a certain part of the room or equipment, the housing can be made from scrap materials. To complete the boiler, you will need to use heat-resistant steel or make it from stainless steel sheets yourself.
First, the power is calculated and the set of components is determined. The best option the snail will be dismantled from old equipment - an extractor hood or a vacuum cleaner. The advantage of this manufacturing method is the exact match between the power of the power unit and the body parameters. A snail fan can be easily made with your own hands only for some applied purposes in a small home workshop. In other cases, it is recommended to purchase a ready-made model industrial type or take the old one from the car.
Procedure to make a centrifugal fan with your own hands.
- Calculation overall dimensions. If the device will be installed in a confined space, special damper pads are provided to compensate for vibration.
- Manufacturing of the body. In the absence of finished design You can use plastic sheets, steel or plywood. In the latter case special attention is given to sealing joints.
- Installation diagram of the power unit. It rotates the blades, so you need to choose the type of drive. For small structures, a shaft is used to connect the motor gearbox to the rotor. In powerful installations, a belt type drive is used.
- Fastening elements. If the fan is installed on the outer casing of, for example, a boiler, mounting U-shaped plates are made. With significant power, it will be necessary to make a reliable and massive base.
This general scheme, according to which you can make a functional exhaust centrifugal unit with your own hands. It may change depending on the availability of components. It is important to comply with the requirements for sealing the housing, as well as to ensure reliable protection of the power unit from possible clogging with dust and debris.
The fan will make a lot of noise during operation. Reducing this will be problematic, since vibration of the housing during the movement of air flows is almost impossible to compensate with your own hands. This is especially true for models made of metal and plastic. Wood can partially reduce background noise, but at the same time it has a short service life.
In the video you can see the process of manufacturing a housing from PVC sheets:
Review and comparison of production ready models
When considering a radial fan volute, you need to take into account the material of manufacture: cast aluminum housing, sheet or stainless steel. A model is selected based on specific needs; consider an example of serial models in a cast case.
When working at a computer in the summer, or just on vacation, sometimes you want a gentle breeze, “local” coolness. The air flow of an office air conditioner doesn't create the sweet comfort of a gentle, directional blast that a mini fan provides. It is very easy to make such a device with your own hands.
How to make a “personal breeze”
The most famous invention in this area since ancient times is folding fans. They were made from painted paper and ostrich feathers, painted silk and carved bamboo sticks. This device has only one drawback: to obtain the much-desired coolness, you need to hold it in your hand, which is not always convenient. It’s funny to imagine a manager or economist working at a computer and fanning himself.
Therefore, let’s return to our topic and figure out how to provide yourself with a pleasant breeze in the heat. To make a mini-fan with your own hands, you need to solve the following several problems:
- What kind of rotating propeller will it be, and what material will it be made of?
- Where can I get a motor?
- What power source will the device operate from?
- Is it possible to do without an engine completely?
How to make a mini fan?
Let's start with the simplest thing: making blades. If you take a square from an ordinary sheet of paper, cut it diagonally, leaving about a centimeter intact in the center, you will get a blank for a pinwheel. Then 4 acute angles bend towards the middle and alternately string them onto a nail, having previously stuck it into the center of the workpiece. That's it! It's a pity that this is just a children's fidget spinner.
For functional and useful design take 2 CDs or DVDs. One will make the blades, the second will make a stand for the device.
The used circle is cut into several equal parts (from edge to center). To make the process easier, you can hold the plastic over the fire for a few seconds. Each of the resulting sectors of the softened workpiece is rotated slightly around its axis to form a propeller.
What other components are needed to assemble a convenient mini fan? Here is the list:
- Cork from a wine bottle.
- Cardboard or plastic straw for attaching the engine to the stand.
- Small motor.
- Two wires.
- Cable with USB contact or batteries.
- Good glue, scissors, a strong large nail or awl.
Where to get a micromotor
It happens that household bins contain appliances that no one has used for a long time. These could be hair dryers or mixers, blenders and children's cars. Even a motor from an old tape recorder, player or some other mechanism may come in handy. We disassemble the unnecessary device and remove the engine, having first disconnected all the wires.
Since we are making a mini fan, the motor is from an old one washing machine, refrigerator, vacuum cleaner or other large unit will not be suitable due to its size and noise.
Continued assembly of the device
A hole is made in the plug and placed on the axis of the selected engine. To secure the shaft, it is first coated with glue. Then the propeller cut from the disk is glued to the part of the axle sticking out of the hole in the plug.
Next, lubricate with glue paper straw in diameter and place it on the plane of the second disk. Then install the motor on top and connect its contacts to the terminals from the USB cable. If, when plugged into the computer port, the propeller spins in reverse side, you need to disconnect the contacts, swap them and solder them again.
By connecting a battery to such a device, you can use it anywhere in the room, in the car, near the pool.
Wind blower without engine
How to make a mini fan at home and at the same time do without a motor? A very popular option is to create a device using small neodymium magnets.
Take the cooler from the computer and separate 4 transformer coils from its body. Instead of copper windings, you need to install and secure the same number of pieces of magnet. Usually they buy neodyms in the form of half-arcs or extract them from unusable hard drive. The magnets are placed exactly in the places where the transformer windings were removed, that is, along the perimeter of the cooler frame.
As soon as the last piece is secured, the mini fan will begin to rotate. Using permanent magnet technology, it is possible to assemble an almost perpetual motion machine. To stop it, one of the neodymium pieces that replaced the coil is removed from the circuit.
The field of the magnets must be equal in strength to the field of the disconnected coils, otherwise the propeller will not be able to rotate in a constant, stable manner. The poles are placed diagonally, alternating plus and minus.
What to do if none of the above methods are suitable, if there is not enough time or details for homemade fan? In this case, you will have to use a regular factory product.
Hot. If I may say so, even too much. That is why you can think about how to make a fan. You will say that it can be purchased at the store. But, firstly, their cost increases significantly. Secondly, they are quickly sold out and it is not always possible to find what you need on store shelves. Therefore, several practical advice about how to assemble a fan. After all, it is quite possible to arrange it even at home from available materials. Here are a couple of options.
How to make a fan based on an old cooler. If you have an old one, you can take it from there. You can also borrow a switch there. More to do homemade fan, you will need some kind of battery holder. There are many of these, you can take it from some broken toy or something else in the same spirit. Of course, you will also need several batteries themselves. All that remains is to connect all these components together, and a simple fan will be ready. If you don’t want to bother with the holder, you can use a regular USB port to supply power. The stand can be made from anything. It all depends specifically on your own imagination and what you have at hand.
You can, for example, make a stand from ordinary rigid wire attached to something. It is not so important what materials will be used, but how stable the entire structure will be.
Another option on how to make a fan may be useful for enthusiasts. An excellent tool will be used for manufacturing computer disks. What else is needed? A motor from a simple toy, a cork left over from champagne, some kind of handy switch and several batteries. We take the disk, and then make as many cuts as we need for the blades. It is necessary to leave about a centimeter to the inner edge. Then turn each blade slightly at an angle. It bends much better if the disk is heated, for example, over gas. Then you will need to insert a champagne cork into its center. If you make a small puncture in its center, for example, with an awl, you can easily attach the entire structure to some kind of pin. You will need to make a leg - absolutely any cylinder-shaped object that can accommodate batteries and wires can play its role.
You will also need to design a base for the entire unit - it can also be anything, the main thing is that it is stable and can support the structure. All that remains is to add a few additional tips - when cutting out the blades you need to make sure that each of them is approximately 45 degrees - you will end up with about 8 pieces. The plug inserted into the center of the disk will need to be secured with glue. In any case, the process should not cause you any difficulties.
If you've been thinking about how to make a fan, you now probably understand that it's very simple. Each of the proposed models is extremely easy to manufacture, and you will not need much time to create it. You don’t need any special things, the above is quite enough. These fans are very convenient and compact. You can put it on your desktop. Or, if there is such a desire, take it with you to the garage or country house, where these devices will serve as cooling means. It’s hard to argue with the fact that they have tangible dignity - after all, these, by and large, very useful things are collected from various rubbish.
As you can see, it is quite possible to make a fan yourself, from scrap materials, without bothering with going to the store and looking for a unit that suits you at an affordable price. Everything is much simpler.
With the onset of heat, we remember fans, the simplest and most accessible human inventions for freshening the air. The classic fan design consists of an engine, onto the shaft of which an impeller with many blades is attached. During operation of the fan, air is sucked in from the rear side and, passing through the blades at an increased speed, is pushed forward, creating a cooling and freshness effect.
Regular fan has a number of disadvantages: noise and vibration from the blades, which collect dust and air pollution. In order to clean them, it is necessary to remove the protective grille. The speed of such fans is regulated in only a few modes, and it can be difficult to adjust the blowing angle.
The alternative device we propose does not have these disadvantages. This development was invented by Dyson engineers, presenting an almost revolutionary solution in the field of air ventilation. Thanks to them, the world learned what a bladeless fan is. And today we will collect it at home.
Operating principle of a bladeless fan
The main difference bladeless fan from the usual is the changed direction of the expelled air flow. This is achieved due to the fact that the engine and impeller are placed vertically and hidden in the base, which is equipped with grilles. Through them, air flows pass into a frame placed above the base and equipped with slots around the perimeter for ventilation.Materials, tools for a bladeless fan
To assemble this cutting-edge household gadget, we will need the following materials:- Sections of PVC pipes with a diameter of 150, 125, 90 mm;
- Quick-drying glue for plastic, such as superglue;
- A small piece of plexiglass or plexiglass blue;
- Server cooler YW880, frame width 60 mm;
- White aerosol paint, 1 can;
- Soft section metal mesh with cells of about 10 mm;
- Rheostatic speed control board, toggle switch;
- Solder, flux, thermal casings, self-tapping screws;
- Segment LED strip, length - about 50 cm;
- Power supply (adapter) 12V/2 A;
- Insulating tape.
- Miter saw or grinder (angle grinder) for cutting pipes from PVC pipes;
- Jigsaw for cutting curved lines;
- Drill or screwdriver with a 50-60 mm crown cutter;
- A set of drills of various diameters;
- Soldering iron, screwdriver, scissors, pliers, hot glue gun;
- Painting knife.
Work order
Preparing plastic pipes
Take a segment PVC pipes with a diameter of 150 mm and trim it, aligning the edges. Mark a fragment about 100mm long and make a cut miter saw or grinder (angle grinder).
The edges of all pipes must be processed sandpaper to avoid burrs, unevenness and improve the fit of edges for adhesive joints.
The next step is to select plastic container, which will fit tightly onto our section of pipe. We cut off the bottom of it with a painting knife, and use superglue to secure it to the top of the pipe.
Then we take a pipe with a diameter of 125 mm and cut off a pipe 90 mm long from it.
The next one will be a pipe with a diameter of 90mm, which we will also cut like the previous two. This is the base of our fan. The length of the segment is 120-130mm.
The basic plastic parts are ready. You can check how they will fit together by placing them in their places.
The fan frame sits perpendicular to the base, so the 90mm pipe needs to be slightly prepared by cutting off its edge according to the circumference of the frame. We mark it with a pencil, you can cut it with a jigsaw or the same grinder.
Unevenness in a curved cut can be smoothed out with sandpaper, removing burrs at the same time.
Using a core cutter with a diameter of 50-60mm, a drill or a screwdriver, we make a through hole in the middle of the largest pipe. This will allow air to flow through the base and into our frame. We fix our base with superglue.
In order to close a fan frame consisting of two pipe sections different diameters, on the smaller of them a plug is glued at one end. We make it from a sheet of plexiglass or blue plexiglass.
Having first marked the larger circle and then the smaller one, we cut off the plug ring.
Now it can be attached with superglue to the smaller frame pipe.
Using spray paint white and electrical tape as masking tape for plexiglass, we paint the plastic parts of our fan.
After the paint has dried, you can glue a piece of LED strip onto the pipe larger size from the plug side. Don’t forget to immediately solder the contacts for LED backlight, and bring them to the base.
We fix both pipes of our frame with superglue.
Electrical part
We begin to prepare the electrical filling of our fan by soldering the cooler contacts. It is better to take the wires with a reserve so that it is convenient to work with them when connecting the control board and toggle switch.
You can use a soldering iron to make mounting holes to securely secure the cooler in the base housing.
We fix the cooler and drill two ventilation holes in the base opposite each other. This can be done with the same core cutter.
We close these holes with fragments of metal mesh, pre-cut to size.
Glue the mesh fragments with a hot glue gun.
We solder the contacts of the toggle switch and the power socket. We cover the exposed contacts with heat-shrinkable casings, heating them with a lighter.
Now you can make holes for the toggle switch and power socket, and secure them to the fan base housing.
So, all you need to prepare is sharp knife, electrical tape, an unnecessary USB cord and, in fact, a homemade executive body. As for the latter, it is customary to use one of two options: an old cooler from a computer or a motor from a typewriter. Next we will look at two instructions that will clearly explain how to do USB fan at home with your own hands!
Idea No. 1 – Use a cooler
As a rule, it will take no more than 15 minutes to assemble a USB fan from a cooler. First you need to prepare the cooler. There are two wires coming out of the device - black and red. Strip the insulation to 10 mm and set the prepared element aside.
Next you need to prepare the USB cable. Cut off one half of it and peel off the insulation at the cut point. Under it you will see four contacts, of which two are necessary: red and black. You also clean them, but it’s better to trim the other two (usually green and white) so that they don’t get in the way. 
Now, as you understand, you need to connect the prepared contacts in pairs, according to: red to red, black to black. After this, you need to carefully insulate the cable connections and make a stand. As for the stand, it’s a matter of your imagination. Some successfully use wire, some very interestingly cut out a seat in a cardboard box.
In the end, the homemade mini fan is connected to the computer, and you can enjoy the operation of your own electrical appliance.
Cooler idea
Idea No. 2 – Use a motor
In order to make a USB fan from a motor and a CD, it will take a little more time, but you can still easily make such an electrical device with your own hands in an hour. 
First, we prepare all the elements of the device. In this case, you will also need an impeller (blades). 
To make the impeller, we recommend using an ordinary CD. Draw it into 8 equal parts and carefully cut towards the center. Next, heat the disk (you can use a lighter), and when the plastic becomes more elastic, bend the blades (as shown in the photo).
If the impeller is not bent, while the disk rotates air flow will not be created. Here you need to use moderation so as not to overdo it.
When the blades are ready, move on to creating the main mechanism. We recommend inserting it inside the disk plastic stopper, in which you need to make a hole for the motor barrel. Carefully fix the core and move on to creating a USB fan support for the laptop. 
Here, as in previous version, it all depends on your imagination. Of all the available means, the option with wire is the most suitable. When the homemade USB fan is ready, we connect the motor wires to the cord wires, carefully insulate the twist and proceed to test work.
Visual video instructions:
Disk idea
CD idea #2
As you can see, in order to make a fan from a cooler or a motor from a machine, it does not require much time and skills in working with electrical appliances. Even a beginner can cope with this task!
