Ballerina drill: adjustable circular drill for wood, tiles and metal. How to choose it

A popular building material, which is natural wood, has unique characteristics and durability, and can be easily processed with various carpentry tools. Among the large list of devices, the ballerina drill for wood has special properties, allowing you to make through or blind round holes of different sizes.

Circular drill device

A ballerina drill for wood is made from carbon, tool, and alloy steels, which are not suitable for processing hard materials: metal, tile, porcelain stoneware.
But they cut drywall and plastic easily. The two-incisor ballerina looks like an ordinary compass. But the design is much more complex. The bracket and cylindrical shank are manufactured in one piece. There are two holes in the bracket. A centering drill is installed in one. A rod is installed in the second. Both are secured with screws.

To set the required diameter, the cutters move along the rod. It has a vernier scale on it. The tool holders are also secured with screws. The incisors are shaped like a knife. The oblique edge of the cutter should be directed in the direction of rotation, clockwise.

If the drill becomes dull during operation, it can be easily replaced. If the cutters are dull, then, having the skills to work on a sharpening machine, you can refill them. The shank of the structure is fixed in the chuck of an electric drill. It is worth remembering that the small power of a power tool may not be enough to work with a ballerina, unlike metal drills.

Drill - ballerina. For large holes.

Instructions on the back. Pay attention to the correct placement of the incisors. Equipment:

The key, the device itself, the drill and the nozzle (if the hole is already drilled) Photo with a ruler:

The design did not fit into a regular drill. We use a hammer drill:

We test on 4 mm plywood. Smallest diameter first:

Cutters after drilling. Apparently after each hole it is better to correct them with a file.

I'm trying to drill a 9 cm hole. I set the speed to almost minimum. It's scary to drill at high speeds:

The cutters come out of the plywood unevenly. Here you need to act carefully.

I was afraid to drill anything other than wood. After the very first hole, the cutters already required correction with a file. The holes are not quite accurate as they are set. The movement of the incisors and vibration affect. With these notes in mind, the drill can be used.

Addition. Shank diameter 1 cm

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How to drill a large hole in tiles

The need to drill large-diameter holes in tiles arises when preparing a place for installing pipes and other plumbing communications, as well as for installing electrical sockets. To drill such holes in tiles, special tools are used, which can be a tubular drill, a ballerina drill for tiles, etc.

The ballerina, with which you can create holes of various diameters in tiles, is somewhat reminiscent in its design of an adjustable drill bit used for working with wood products. The ballerina works on the principle of a compass: the central drill serves to center it, and the working cutter, which can move along a special bracket, cuts a hole of the required diameter on the surface of the tile. By adjusting the position of the cutter, it is possible to obtain holes whose diameter is in the range of 30–90 mm.

Drilling a hole with a ballerina

At the same time, the ballerina is unproductive, since you can only work with it at low drill speeds. Moreover, such a tool is not very convenient to use, since it is quite difficult to hold it in one position.

More effective (but also expensive) is a circular tile drill, which is often called a tubular drill. Its cutting part can be coated with diamond or tungsten carbide.

Drilling tiles with a tubular drill without a center begins at low speeds, slightly deflecting the drill from a vertical position

When using a tubular drill, you should adhere to a number of rules:

perform drilling at a rotation speed not exceeding 500 rpm;
intensively cool the tool during processing;
use the tool only on a stationary drilling machine, if its design does not provide for it.

Features of the device

The design of the device is simple, reliable and high-performance.
A circular drill, or ballerina drill for cutting gaskets, consists of a central drill with a groove, a round or triangular shank, two carriages and cutters located on the arms of the bracket. The purpose of the drill is to mark the center for the hole and provide support for the device during rotation. There are special markings on the bracket rod for installing the sliding carriage in the desired position. The cutters are fixed with screws, and the spread of the working edges is checked with a caliper.

A distinctive feature of a ballerina with one knife is the asymmetrical design and a noticeable lever that counteracts rotation, creating a high range of oscillation of the instrument. For this reason, experts recommend using the device on a stationary drilling machine. This will help prevent the work material from falling off and protect the worker.

The best option when working with a drill, screwdriver, hammer drill or rotary hammer is a system of two cutters that compensate each other in terms of balance during rotation. The disadvantage of the design is the rapid heating of the cutting part; the drill must cool down several times during the task. To maintain the functionality of the tool, it is recommended to maintain an operating mode ranging from 1000 to 1400 rpm.

DIY making

When you don’t have a device at hand that can cut a circle from wood or other material, you can try to make it yourself. To do this, you will need a collet holder and a set of the required size of feather drills. A collet holder is a clamping mechanism that is used to clamp a rotating cutting tool. It can be made from a bolt, the diameter of which depends on the chuck of the rotator, machine tool or drill. The head of the bolt needs to be cut off and sawed crosswise along the thread side.

The center drill is sharpened into a cone, and the cutting drill into a wedge. In this case, the end of the center drill should be 3-5 mm longer.

The drill is held in place by two nuts: one is a clamping nut, the other is a guide. If holes with a constant radius are cut, then the drill can be welded to the holder.

Design Features

The design of any ballerina includes the following elements:

a rod with which such a device is fixed in the chuck of an electric drill;
feather-type centering drill;
adjustable bracket on which the cutting tool is fixed;
a cutter, the working part of which is coated with diamond sputtering or a carbide plate is brazed.

Ballerina device

When choosing a ballerina to perform work on tiles or ceramic tiles, you should not save money. A high-quality tool, the price of which is significantly higher than that of simpler models, will not only allow you to get the job done efficiently, but will also not ruin the tiles, which may cost even more than the ballerina used to drill them.

Design and principle of operation

The design of a circular drill is quite simple and mainly consists of three parts:

a drill responsible for centering the device;
a fastening rod of a certain length on which the cutting elements are installed;
cutters equipped with a device for attaching them to a rod, their number ranges from one to three.

This design is used on single and double cutter models. If there are three cutting elements, then in this case the cutters are fixed on a round disk, and to change the radius they move along the grooves. Additionally, some models can be equipped with a protective cover that protects the working person from flying chips or sawdust. It also protects the worker from being hit by fragments when the device is destroyed.

Now let's see how to drill. The central drill needs to be drilled at a pre-designated point. If the materials are durable, for example, iron, tiles or laminate, then it is better to first mark the drilling location with a regular drill. This is done for convenience so that the “ballerina” does not slip on the surface and scratch the top layer.

Next, we cut a path of the radius we need

Again, here you need to pay attention to the material in which the holes are drilled. If it is a tile, then to prevent damage to the facade surface you need to drill at low speed and lubricate the tile with water or machine oil

This will prevent damage to the tiles and the scattering of fragments. Tile panels must be laid on a flat surface, otherwise they will crack under force.

If the tile is already attached to the walls or floor, then you only need to cut through it, and then replace the “ballerina” with a concrete drill. When drilling laminate or veneer, it is difficult to go through the top layer, but then it goes easier. There are no special instructions for wood, iron, plastic and drywall. The last stage is removing the cut out objects.

In addition to the basic instructions, there are a few additional nuances.

In no case should you put pressure on the tool or lean on it with your whole body: this can damage the device and split the material in which the hole is made;
“impact” or “perforator” modes cannot be used, only drilling;
there is no need to let the “ballerina” overheat: high temperatures can deteriorate the coating of the incisors;
if drilling is difficult, then you should add speed.

To protect your health when working with a device for drilling circular holes, you need to follow simple rules:

Before starting work, you need to check whether all components of the device are securely fastened;
You should wear goggles or a mask to protect your eyes;
clothing should not contribute to getting into the rotating elements;
If possible, be sure to install a protective grille on the ballerina.

What can a “ballerina” do?

We continue to get acquainted with various tools, today we will analyze a circular adjustable drill, in common people it is called a “ballerina”, apparently by analogy with the appearance of the drill during its work with a spinning ballerina. The main purpose of this tool is to drill large diameter holes in tiles.

I’ll immediately give you a link to my other article about diamond bits - here it is, with the help of which you can also make large-diameter holes.

As you can see, there are many things you can use to drill into tiles; some people prefer to work with a ballerina, while others prefer to use crowns. Let's continue.

With its help you can drill “holes” in tiles with a diameter of 30-90 mm. As you can see, the maximum size is very large, it will be difficult to find such a crown (and I won’t say anything about how much it will cost), so when you need to make a hole larger than 60 mm (as a rule, crowns are sold individually up to this diameter), you have to use a “ballerina”.

It consists of a centering drill and a second cutting element fixed parallel to it and moving along a guide. The cutting part and centering are equipped with hard alloy tips, which actually cut the tiles. The main cutting plate moves along a guide, the minimum diameter is 30 mm, the maximum is 90 mm. The moving cutting part is secured using a bolt.

From this we can conclude that, if desired, you can drill a hole of any diameter in the range of 30-90 mm. Agree, you are unlikely to be able to find a diamond crown with a diameter of, for example, 53 mm. But such a circular drill will cope with the task without any problems. That is why they are in demand among finishers involved in cladding. It can be safely called universal - any diameter within the tolerance without any problems.

According to customer reviews, these drills have proven themselves well when working with tiles. Of course, the cut is not as smooth and even as when working with a crown, however, if a clean cut is not required (for a socket in a tile, for example), then purchasing this drill will be optimal.

How to work correctly?

The work is done using a drill; if it is an impact drill, then the impact mode must be turned off.

We drill at low speeds, it is very important that the carbide plates do not overheat, then your drill will serve you for a very long time. I remember once the neighbors called a plumber, so he got a ballerina that looked as if it had been worked on for many years. I already thought that the master would not be able to do anything for them, but to my surprise, the hole in the tile was made quickly and very efficiently. This is what it means to use a tool correctly. The master drilled carefully, at slow speeds, without pressing hard on the drill. The tile was drilled like clockwork.

The price for it is around 230 rubles, if you look at how much diamond crowns cost, then it’s better to buy it, it will be cheaper. If used correctly, it will pay for itself many times over. Of course, if the holes must be neat and even, then priority is still given to crowns.

— If you need holes, the edges of which will still be hidden later, then take a ballerina. - If the “holes” are clean (you won’t hide the edges) - then there will be crowns.

And of course, a video about how to use this very “ballerina”.

As you can see, everything is simple and clear. Hold on, tiles now))

Another note: How can you unscrew a broken bolt?

Types of instruments

In addition to the classic two-cutting version of a circular drill, there are one- and three-cutting models. In the design of a single-cut drill, the cutting part is directly fixed to the rod. The cutter and centering lance are equipped with carbide plates. They make it easier for a ballerina to work on tiles.

In three-incisor models, the incisors are mounted on a round platform on which there are grooves. The cutters move along these grooves. They have a scale. Correctly set size allows you to cut more accurately and quickly.

Currently, some models are equipped with a protective grille made of plastic. It improves work efficiency and convenience.

The ballerina for metal is equipped with plates made of hard alloy with sharpening of a cutting turning tool. High cutting force dictates the use of stationary or portable radial drilling machines. Basically, holes are cut in galvanized sheets, the thickness of which does not exceed one millimeter.

How to make a “ballerina” for cutting circles in soft sheet materials

Hello, dear readers and DIYers!

When making various parts for homemade products, sometimes you need to cut a large round blank or hole in a soft sheet material such as leather, rubber, paronite, cardboard.

In this article, the author of the YouTube channel “TEXaS TV” will tell you how he made a simple hand tool to perform these tasks.

Despite the lathe used in the manufacture of some parts, this tool can be made without turning.

Materials. — Round steel, rod — Old drills, M3 screws — Sheet paronite — Abrasive polishing paste, felt, sandpaper — Two-component epoxy glue, machine oil.

The author makes the cutter and needle from a pair of old 6 mm metal drills.

Now radial holes are drilled in the holders for screws that will secure the cutter and needle. Then an M3 thread is cut into them.

A transverse hole for the rod is made in the upper part of the holders. Moreover, in the needle holder it will be deaf, and a thread is cut in it.

In the second, slider holder, it will be through and have a diameter of 8 mm. In addition, a 6-mm axial hole is drilled into it, and an M8 thread is cut into it from the tail part.

Features of working with the tool

The principle of working with a circular drill is simple. A hole is drilled using a centering drill, and then the cutters are put to work. They gradually make a narrow groove, gradually cutting through the material in a circle to the full depth.

The materials used in working with the ballerina are varied: wood, fiberboard, chipboard, MDF, plasterboard, plastic. One common point is that the thickness of the part should be no more than 15-20 millimeters. This parameter is limited by the length of the incisors. Usually the manufacturer indicates the maximum drilling depth on the packaging. If you try to drill into thicker material, you may experience problems with ragged edges.

The use of a tool with one cutter is characterized by runout. This is caused by a lack of balancing relative to the longitudinal axis of the drill. The beating will be especially noticeable when cutting large diameter holes. Cut holes using a drill at low or medium speed. When working on a drilling machine, such problems do not arise.

Also, a laminated or veneered surface can cause inconvenience when working. After passing through the decorative layer, drilling proceeds without problems.

A feature of the circular drill can be considered the ability to adjust the diameter. The distance between the cutters can be set using a scale on a rod or more accurately using a caliper. This is convenient if you need to make a hole without gaps for a pipe or round part.

The spacing of the cutters relative to the center is adjusted individually. It is necessary to align the cutting parts as accurately as possible. This will eliminate unnecessary effort during operation and extend the life of the tool.

Characteristics of a wood drill

When working with hard wood, fiberboard, chipboard, plasterboard and plywood, drills are selected individually, taking into account the thickness of the material, which should not exceed 1.5 cm. A do-it-yourself wood ballerina is assembled from a set of drills and replacement parts included in the equipment set . The structure can be rotated with a rotary hammer, drill or drilling machine at low or medium speeds.

The work process is divided into several stages:

Drilling with a central twist drill,
Cutting paths around the circumference,
Removing a cut element.

The main condition for working with loose wood is the choice of tools for drywall. When making blind or through holes, fixtures made of carbon and alloy steel are used.

There are two ways to drill a quality hole with smooth edges:

By drilling a small diameter grommet from both sides to the middle of the board
By drilling through a wooden spacer.

Working on material with a laminated or veneer surface requires preliminary marking of the drilling location with a core or an awl.

Device capabilities

The device for working with wood has a long service life, lends itself well to sharpening knives at the desired angle, and makes it possible to create a gap with a radius of 2.0 to 15.0 cm. For safety reasons, the master is recommended to use a tool equipped with a protective grill screen.

How to choose and what to pay attention to

Choosing a high-quality circular drill is quite easy

The main thing is to know the main points that you should pay attention to first, but also not to lose sight of the little things

The design is a very important point: a wood ballerina comes with one chisel or two or more. For frequent use, it is better to purchase an option with two or three cutting elements. It is easier to work with such devices and the quality of the processing performed will be at an acceptable level.

It would not be superfluous to be able to replace individual parts. Inexpensive circle drills can have a solid shank with a permanent center drill and rod.

Metal, its quality determines its strength and ability to withstand workloads. High-quality tools are made from high-strength steel or alloys. The shank and cutter holders are shaped using a machine tool. The rod is usually stamped and made of the same metal.

Cheap options often use soft metal or alloys, which can be brittle. Under load, parts may become deformed or break. Such a tool will not last long and it will also be difficult to achieve accuracy from it.

The quality of workmanship, the main feature is the absence of backlashes and distortions. All parts must fit together and be securely fastened with fixing screws.

The markings of a high-quality ballerina's barbell are stamped. Sometimes the divisions are highlighted with bright paint for better visibility.

Cutters and high-quality cutting elements are made from hardened tool steel. They are secured to the holders with rivets or soldering. Solid cutters with holders (made of the same metal) quickly become dull and are not durable.

Manufacturer, when choosing any tool and consumables, preference should be given to well-known and long-proven brands and brands. The most common are Topfix, Stayer, Irwin, Strum.

Purchasing an adjustable circular drill for use at home, or if you need to drill several holes, is completely worth it. This eliminates the need to purchase an expensive tool that may only be needed a few times.

Advantages and disadvantages

The advantages include:

possibility of changing the centering element;
equipped with two types of centering elements;
cutters can be sharpened;
no additional processing required;
reliable design;
the locking screws are fixed by a cone;
The screws are tightened using a hexagonal socket wrench.

Among the disadvantages it is worth noting:

poor sharpening of cutters;
on inexpensive models, when processing large diameters, breakage is possible;
A high power drill is required.

Criterias of choice

Before choosing a “ballerina”, you need to know its main advantages over other devices for cutting large holes, be it crowns, jigsaws, etc.

Advantages of adjustable circular devices:

the ability to replace the central drill or lateral incisors at any time;
reliability of design;
if necessary, cutting elements can be sharpened;
adjustable hole width.

Now let's look at the parameters you need to pay attention to when purchasing

Reliability. It is unlikely that you will be able to determine this criterion visually, so it would be better to check the quality certificates for the products from the seller. For low-quality goods, they most likely will not be available.
Workmanship. Before purchasing, you need to carefully inspect the device for shells, chips and other flaws. The cutters must be well and accurately sharpened. If the drill is very long, then you need to check whether it is even. Usually these defects are visible immediately and by eye.
Package. Quality products from well-known manufacturers usually come with bright and good packaging. There will be no grammatical errors in the text accompaniment. None of the well-known brands can afford to package their products poorly.
Price. Cost can also be considered an indicator of quality. Inexpensive models last a very short time.

Famous brands care about their reputation, and their products will meet all quality criteria. Therefore, it is better to contact official dealers so that the money is not wasted.

The following video talks about the ballerina drill.

Method of drilling holes with a ballerina

Please note: Before starting drilling, when the intended hole is marked, mark the drilling center mechanically. For this, a regular drill is used. The ballerina may slip on the tile (at the first touch) and scratch the tile.

The use of hammer drills is prohibited. If you have a multi-mode drill, the hammer function should be disabled. It is recommended to immerse the workpiece in water in advance. There will be no harm to the tile, and there will be much less chipping and dust.

In principle, there are two ways of drilling: before laying the tiles, and on the finished tiled surface.

Drilling individual tiles

The workpiece is placed on a flat surface. The thickness of the backing should allow the center drill to deepen 4-8 mm relative to the main cutting element.

You can hold the tiles with your hands, although it would be better to secure them with clamps. You must be prepared for the fact that after the ballerina passes through, the cut out circle will rotate freely. For control, it is recommended to periodically stop the process and check the depth of the cut.

Drilling a hole in the tile with a ballerina with a basket - expert advice

What is a ballerina

The cutting tool, commonly called a ballerina, also has a more professional name - “circular adjustable drill with cutters.” The drill is located in the central part of the tool and is used to center the hole. The radius of the circle that the cutters will describe is measured from the center line of this drill.

To equip ballerinas, drills of the first or auger type are used, since a conical tool does not cope well with ceramic materials and can slide off their surface. The result of such slipping can be damage to both the tool itself and the surface of the tile.

Ballerina on tiles differs from a nozzle designed for drilling holes in wood materials

Other tools used for the same purpose

In addition to the ballerina, other devices can be used for processing wood:

Tool	Features of design and use
Feather drill	It is a rod with an expanded blade in the shape of a spatula and a spear-shaped tip.

Drilling range from 10 to 60 mm, maximum depth – 150 mm.

The quality of the edges is relatively low.

Set of crowns of different sizes

Use of special drills

Special drills for ceramic tiles are used in cases where it is necessary to create a hole of small diameter. As such a tool, if you need it to make just a few holes in the tile, you can use a regular wood drill, sharpening it sharper, but a metal drill equipped with pobedit tips is better suited for these purposes. The resources of the latter, if it is provided with high-quality cooling, will be enough to make more holes.

Among the inexpensive drills for ceramics, with which it is convenient to create holes for dowel fasteners, spear-type tools should be distinguished. Using one such drill, the diameter of which can be up to 12 mm, you can create up to five holes in the tile. When using this tool, you should keep in mind that you can drill tiles with it only at low speeds of the drill.

Varieties of spear-shaped drills for tiles and ceramics

You can also drill tiles to accommodate dowel fasteners using drills equipped with carbide plates and toothed cutters. The latter differ from conventional carbide-type drills in that their cutting plates have a one-sided and sharper sharpening. The disadvantages of using such tools are that it is quite difficult to obtain a high-quality result with their help, and before drilling, the center of the future hole must be punched.

A pen tool for drilling tiles is more convenient to use. The advantages of such a drill are that before using it there is no need to pre-core the tile, and it is much easier to aim it at the center of the future hole. Using tile drills, the cutting part of which is shaped like a feather, you can make holes with a diameter of up to 30 mm.

The most expensive, but also characterized by the longest service life, are spear-shaped drills, the cutting part of which is coated with diamond. It is advisable to purchase such expensive and reliable drills when a large amount of work needs to be done with their help.

Tubular tile drills with diamond coating

Experts advise adhering to the following recommendations when drilling holes in tiles intended to accommodate dowel fasteners.

Once the tiles already attached to the concrete wall have been drilled through their full thickness, the tile drill should be replaced with a concrete tool. In this case, the drill or hammer drill can be set to impact mode. This approach can significantly extend the service life of a drill designed for working only on tiles.
To prevent accidental damage to a tile fixed to a concrete base when driving in a dowel, the hole in it must be larger in diameter than in the concrete.
In order to drill a hole in the seam between two tiles without damaging them, you should choose a tool whose diameter is smaller than the width of the seam.
When hammering in a dowel, you must act very carefully so as not to accidentally damage the surface of the tile.

Ballerina wood drill: the device of the tool, its technical capabilities and use

Wood is almost always easy to process with various tools that have a cutting edge. Quite often, wood craftsmen have to drill into chipboard or fiberboard material using various drills to make furniture or wood crafts during construction work.

It is often necessary to make large holes, for example, in wooden house construction or for fastening parts. The holes can be through or blind, and to make holes of large diameters you will need a special drill called a ballerina. What kind of drill is this, what does it look like and what technical capabilities does it have?

Ballerina on wood

To work in a home workshop, you can get by with ordinary drills for wood and metal, but to perform special complex operations, a specialist cannot limit himself to a minimum set of tools.

Having a good electric drill, you can make a hole in wood with a diameter of no more than 2 cm using a metal drill. For hard wood or loose materials, it is necessary to select special tools that are designed for each specific case.

When craftsmen need to drill a large hole, a drill with the unusual name ballerina comes to the rescue. This is a common name, very common among woodworkers.

Using such a tool you can make holes with a diameter of up to 300 mm in materials such as:

The ballerina consists of two cutters and a centering drill, with the help of which the circle is cut. The cutters move along the guide and set the desired diameter of the circle for cutting. The ballerina must be rotated using a drill or a rotator at low speeds, so the tools can be rotated manually.

A round drill with cutters can be adjusted to the desired diameter; the design also has a centering drill, which can be used to pre-drill into the surface of the material and fix the product.

Moving cutters with a sharp tip are designed for direct cutting of material; there is also a bracket on which moving elements are secured.

A ballerina can have a different number of incisors, from one to three, it all depends on the shape of the device and the price of the special drill.

The principle of operation of the ballerina is simple, first the central spiral drill makes a preliminary drilling in the material, and sharp sliding cutters around the circumference of the surface of the material cut a groove. They are spread to the same width from the center and then fixed with a special key.

How and with what to drill wood

To drill small holes with a diameter of 10–12 mm, ordinary metal drills are most often used. If every millimeter in the position of the hole is important, then it is necessary to use special drills, since the metal tool may deviate to the side when entering the wood.

If you need to make a hole with increased accuracy or large sizes, then it is better to use a special drill. They are always made from tool alloy and carbon steel grades, which cannot be used for metal processing; they are intended for woodworking.

To ensure that the hole is of high quality and that the drill does not go to the side, before starting drilling, make a small indentation with an awl. The entire drilling process must be carried out at low and medium speeds to avoid chipping at the exit of the drill when you need to get a through hole. This can be done in two ways.

Make a thin hole and then drill along it on both sides of the object to the middle using the required drill to obtain a circle of the final diameter.
The second method is when a wooden spacer is applied to the surface of the object on the side where the hole needs to be drilled, and it is removed when the work is completed.

Read also: PKP 3 precious metals content

Due to the fragility of the structure of the material, for example, chipboard, special attention is required from the master to make a high-quality hole. The laminated or veneer surface of the object complicates the task. In this material, you must immediately make a mark with an awl and then drill a hole using a lining.

Technical capabilities of a ballerina on wood

The special tool is made of a durable type of steel, so with such a tool you can perform all work on wood, as well as other materials, with high quality. The strength of the steel will ensure a long service life for the tool.

It is important that the ballerina can perform a wide range of tasks, the drill allows you to make holes with a radius from 20 mm to 150 mm, and the diameter will be twice as large.

Currently, there is a tool that is equipped with an additional plastic protective grille, and this provides its advantages - increased convenience and efficiency of operation.

Types of instruments

Ballerina drill can be of several types. The single-cutter tool has a special bracket with a tightening screw perpendicular to the drill. Before starting drilling, the cutter is tightened to the required length and the screw is then immediately tightened, the drill is ready to perform its operation.

A two-cut tool has cutters that are located on a bracket. The fastening bolts in such a ballerina are located on the cutter holders; they are independently installed at the same distance before the drilling process begins.

A more complex instrument is a ballerina with three incisors; they are mounted on a round platform and move along special grooves.

This is how the required diameter for drilling is set; it can be accurately set using the existing scale. The cutters work synchronously, so the distance from the center will always be the same. The scale greatly helps make cutting more accurate.

For small volumes of work, a ballerina drill always copes with its task and quickly pays for its cost immediately after a couple of holes are made with its help. Other types of tools for such work will cost much more and may only be needed a few times.

Author: Nikolay Ivanovich Matveev
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Where and what drill is best to buy?

As for foreign-made tile drills, the domestic market offers mainly American, Polish and German models. Their price is much higher than domestic ones, and the packaging is more beautiful. In terms of quality, they are not much different from Russian ones. Therefore, there is no need to overpay. A separate price category consists of the so-called “professional” tile drills. Not everyone can afford them. But they are also very easy and convenient to work with. Their appearance is also simply amazing. The soldering of the plates is carried out with the highest degree of care and precision, the joints are almost invisible. The tip is sharpened in such a way that it is simply impossible to replicate at home. In addition, these tile drills also differ from ordinary ones in that they have a set service life, during which they cannot become dull. After its expiration, the drill loses its “professional” status and, after sharpening at home, can be used as usual.

Types by number of incisors

The design of a ballerina is influenced by the number of incisors with which it is equipped (their number can vary from one to three).

The design of ballerinas equipped with one cutter has a special adjustable bracket with a tightening screw. To start working with such a tool, use a bracket to move the cutter to the required distance from the axis of the central drill, and then fix its position using a tightening screw.
The cutting tools of two-cut ballerinas are also located on a bracket, which is motionless. Adjustment of the position of the cutters relative to the axis of the central drill is ensured by movable holders on which clamping screws are installed for fixing the cutting tool. The position of each of the incisors of such a ballerina is set separately, and, of course, their distance from the axis of the central drill must be the same.
The three-incisor ballerina for tiles and ceramic tiles has the most complex design. The basis of such a tool is a round disk-type platform, in special grooves in which the cutters move. A special scale applied to the body of the device platform in the area of its grooves allows you to accurately set the position of the cutters and, accordingly, obtain holes of the required diameter. The movement of all three cutters of such a device is synchronized, which allows you to quickly, easily, and most importantly, accurately set the position of each tool relative to the axis of the central drill.

The protective basket on some instrument models protects against flying fragments

Modern models of one- and two-incisor ballerinas are also equipped with a scale for determining the exact position of the incisors relative to the axis of the central drill. It should be borne in mind that the accuracy of the holes obtained by a ballerina with such a scale is much higher than when using a simpler tool.

It is necessary to choose a ballerina of a more complex design in cases where it is necessary to drill a large number of holes in ceramic or tiles. A tool equipped with multiple cutters not only improves the productivity of the drilling process, but also creates holes with higher accuracy.

Specifications

Carbon steel is used to make the device. It is an alloy of carbon and iron. The amount of carbon determines the strength of the tool, its ability to resist load. For greater wear resistance, less sensitivity to overheating and deformation, some manufacturers add chromium, silicon, tungsten, vanadium, and molybdenum to the alloy. For example, the P6M5 marking indicates that the steel from which the cutter or drill can be made contains 6% tungsten, 5% molybdenum, this increases strength.

For strength and increased service life, the drill tip can be tipped with carbide. Such devices give a cutting depth of 30 mm, and without soldering - 25 mm.

Comfortable operating speeds for the tool will be from 1000 rpm to 1400 rpm.

The ballerina, depending on the functional accessory, makes holes whose radius ranges from 20 to 150 mm, while the diameter of the cut circle will be 2 times larger. For example, using a tabletop drilling machine or drill, a ballerina for metal allows you to cut or drill holes in metal with a radius from 22 to 105 mm. The thickness of the material being processed should be up to 14 mm. The material can be steel, cast iron, brass, bronze, aluminum.

Technical capabilities

The main use of ballerinas remains cutting sheet material. The ability to adjust the diameter allows you to use one tool for several purposes. Two or more cutting elements allow you to obtain a high-quality processed surface.

Almost any sheet material used in construction, repair and decoration can be processed with a circular drill. Carbon steel gives the structure strength. Special coatings are used to protect against corrosion.

The price range depends on the material of construction and cutting part, manufacturer, size and number of cutting elements.

How the tile cutting process is performed

There is a certain algorithm that should be followed when using a tool for drilling holes in tiles, like a ballerina.

First of all, on the front side of the tile it is necessary to mark the center of the future hole, for which you can use a regular core.
The cutter or cutters of the ballerina, which will do the main work of cutting the material, are installed and fixed at the required distance from the axis of the central drill.
It is advisable to lubricate the area of the tile on which the cut will be made with machine oil. In this case, you should make sure that it does not fall into the center of the circle, which can lead to the drill slipping.
The drill, located and rotating in the center of the future hole in the tile, must pass through its surface before the cutters, so it must be longer than their protruding part.
The tile in which the hole is made using a ballerina must be firmly fixed on a flat surface of a wooden board or drywall. To ensure such fixation, you can use ordinary clamps.
Drilling the hole is carried out at low speeds of the tool, and it is advisable to constantly water the groove formed on the tile with machine oil.
After the cut in the tile has been made to more than half its thickness, and the central drill has passed through the material being processed, the product is turned over and similar processing is performed on its reverse side.
The tile is drilled to the end from the back side, and the edge of the resulting hole, which may not be too smooth, is processed using a file, emery cloth or a grinding machine.

Despite the fact that the holes made with the help of a ballerina do not have very smooth edges, it is quite reasonable to use it to perform not too voluminous work. In addition, the uneven edges of the holes will later be hidden by external panels of electrical outlets and other decorative elements.

Types of ballerinas

For woodworking

In a home workshop, when working with wood material, you may need a tool for cutting round holes. These tools include a drill, which in everyday life craftsmen who work with wood or wood-based materials call a ballerina. The exact name of this device is a circular drill.

The design of the tool is a bracket, along the axis of rotation of which the drill is fixed. It marks the center of the hole and provides rotational support for the entire fixture. At the edges of the bracket there are two carriages in which the cutters are fixed. The bracket rod is marked, so the carriage with cutters can be installed with high precision. Before starting work, the lateral incisors are moved apart to the required distance. They are pressed to the bracket with screws.

There are other modifications of the woodworking ballerina with one, two or three cutters. The bracket can be replaced with a disk, in special slots of which cutters are placed to adjust the diameter. A hole can be drilled straight or at an angle in the axis into which a cutter is inserted, adjusted with a locking screw. It provides the size of the diameter of the resulting circle.

The tail of the axis can be round or specially shaped for fixation in the SDS chuck. To remove a straight or rounded chamfer, where necessary, knives of various shapes are used.

In addition to wood, the material with which this device works can be drywall, plastic, rubber, tile, or metal.

Drilling drywall

For installation of various equipment in plasterboard with a diameter of up to 100 mm, a ballerina for plasterboard is designed. It is a leg with a centering tip, above which there is a mount for the rod, rotating around its axis. In order to hold the tool, at the end of the central post there is a handle with a notch along the side surface. At the other end of the rod there is a disk cutter.

Tile tool

During construction or renovation work, it may be necessary to make a round hole in the tile. This is necessary for installing a socket, switch, leading plumbing pipes or other elements through the wall.

To work with tiles, single-cut, double-cut and three-cut annular drills are actively used.

The use of these devices promotes a perfectly even cut of tiles without chipping the enamel. By arranging and fixing the cutters at the required distance, you will get a hole of the required diameter and size. Using a circular drill will significantly save time and reduce labor costs. The operation of the instrument is similar to how a ballerina dances.

Drilling process steps:

On the face of the tile, mark the center of the hole.
Fix the tile.
Place the cutters or cutter in the desired position.
Treat the cut area with machine oil.
Start carving at low speed.
To finish the carving, you need to turn the tile over to the other side and continue drilling.
Use a file to finish the edges of the hole.

Peculiarities

The main feature of the ballerina drill (its full name sounds more than impressive - “adjustable circular drill with cutters”) is the ability to change the diameter of the circle being cut. The distance between the cutting elements can be adjusted using an auxiliary scale on the mounting rod. If maximum accuracy is required, then you will have to use a caliper. This is quite convenient when it becomes necessary to make a hole for a pipe or other round part without backlash.

The second distinguishing feature is the number of incisors. It can be from one to three, and the quality of processing of the edges of the cut holes depends on this. If you purchased an adjustable drill with one cutting element, then you need to be prepared for the tool to “beat”. Vibration increases with increasing diameter of the cut hole: the larger it is, the higher the runout. This is due to the fact that there is no balancing relative to the longitudinal axis.

Adjustable tool overview

Ballerina – adjustable drill. One of its structural elements is a bracket with a scale printed on it. With its help, you can independently set the required diameter. And in a three-cut drill, the cutting elements move synchronously along special grooves.

Before starting work (drilling), it is necessary to set both cutters at the same distance from the central hole.

Characteristics of metal for drill

The drilling process is the mechanical and physical impact of the drill, therefore the raw material from which it is made must have properties such as:

Strength. This will ensure drilling through thick layers of wood.
Fatigue strength. It characterizes the drill’s ability to withstand cyclic loads when in contact with wood.
Plastic. Allows you to carry out operations to prepare the drill for work.
Hardness. Determines the durability of the metal.
Heat resistance. Preserves the mechanical properties of the drill when heated at high drilling speeds.
Corrosion resistance. Possibility of drilling into raw wood.

We are sure that you will find this article useful about what types of concrete drill bits are available for a rotary hammer.

Making a ballerina cutter

A ballerina drill significantly saves time when processing (milling) the contours of a cut hole. Processing is carried out automatically using power tools (drill, hammer drill).

Therefore, the physical effort expended when working with a ballerina is also insignificant. Given these advantages, home craftsmen want to have such a tool in their workshop. Moreover, making a ballerina with your own hands is not at all difficult for a competent craftsman.

For this you will need materials:

Working (metal) plate with dimensions 200x25x4-6 mm.
Bolts: M8 grade - 2 pieces (in addition to them you need to take 2 nuts and 4 washers) and M10 grade - 1 piece (in addition to them you need to take 2 nuts and 1 washer).

To work you will need tools:

To mark the work surface: a marker and a ruler with centimeter divisions.
Painting tape.
Stationary machine or power tools (hammer, drill).
Vise.
File.
Kern.
Grinder equipped with grinding and cutting discs.
Drills for metal with a diameter from 9 mm to 10.5 mm.
Keys: open-end and adjustable.
Screw clamps.

Step-by-step instructions on how to make it yourself

Marking and processing of the work plate.
Creation and processing of working grooves.
Manufacturing of cutters.
Connection of cutters to the working plate.
Marking (gradation) of the finished drill.

At the first stage, we cut a 20 cm long strip from the metal sheet. This will be the basis of the tool being created.
Using a drill with a diameter of 10.5 mm, we drill a through hole on the machine in the pre-punched center of the work plate.
Stepping back 1 cm from the drilled hole to the edges of the working plate (at the same level as the central hole), we make marks (punch) on the plate for future drilling.
The distance between the marks must exceed the diameter of the holes that will subsequently be drilled. This precaution will help preserve the drill.
Using a grinder cutting disc, you need to create two oblong grooves by combining the existing holes. The working plate is in a vice during this operation.
Using a file (square or flat), we process the resulting holes. The free movement of the incisors will depend on the thoroughness of this operation (we remove irregularities, hangnails, and tubercles).
Pressing the work plate tightly against the table (we use clamps or a vice), we smooth out all the irregularities and sharp corners with a grinding disc. We insert an M10 bolt into the central hole and screw one of the nuts onto it from the reverse side.
We put the second nut (lock nut) on it and press it tightly using an open-end (or adjustable) wrench. To make the cutters, we wrap the upper parts of the M8 bolts with masking tape. We fix the bolt heads in a vice.
Using a grinder's grinding disc, we cut off the thread, processing the bolt on both sides until a metal handle 4-5 mm thick is formed.
The pointed ends of the bolt, shaped like a one-sided hook, will serve as the working cutters of the drill. The resulting cutters must be inserted into the grooves, having previously been laid with washers on both sides.
This will increase the area of their contact with the working plate.
The rod of the future tool and the cutters should be located in opposite directions. The thread sections remaining on the side surfaces of the bolts will allow you to screw on the nuts and secure the cutters tightly.
Using a ruler and a marker, we mark the entire plane of the working plate, making marks every 0.5 cm. Later on these marks it is necessary to make notches that will be clearly visible during operation.