Movable connection of metal parts such as dovetail. Dovetail Corner Connections

The key stage of wooden construction is the correct assembly of a log house from a bar.

In order for all work to be carried out correctly, you need to know how to connect the beam to each other.

There are many mounting methods, the choice of the appropriate one depends on the complexity of the project of the structure being erected.

In modern wood construction, angular and longitudinal methods of joining timber are practiced.

Docking methods are presented in various variations, but the most popular are:

• Residual - in a bowl, in a cloud, in an ohryap, in an okhlop;
• Residual - in the tooth, in the paw.

Residual ways of corner docking

The most common option - fastening "into the bowl" is:

• One side;
• On two sides;
• On four sides.

Grooves on one side

This option is performed in such a way that in each element in the connecting places a perpendicular groove (bowl) is cut. The cutting is carried out only from above, while it must fully correspond to the size of the log laid on it.

A similar technology is often used for profiled timber.

Grooves on two sides

In this case, the groove cut is performed in the upper and lower parts of the element, while each of them must be of the same depth.

Important! The depth of each cut should be one quarter of the height of the element.

Grooves on four sides

This method involves the preparation of cuts on all four sides. This ensures high fastening strength and durability of the finished structure.

With the correct calculation of the diameter and accurate sawing of the grooves, all the components of the wooden structure fit without any effort.

Corner docking in the "oblo"

Comes in three variations:

• half a tree;
• Kurdyuk;
• Comb oval.

half a tree

The most affordable docking method for implementation, which provides for the presence of a longitudinal (laying) recess on the base being laid.

Before joining the upper and lower elements, the recesses are filled with insulation, which provides stronger fastening and additional insulation of the structure.

Oval comb

The connection of a bar called “oval-shaped comb” involves the preparation of a laying groove, in which an oval-shaped comb is cut, coinciding with an oval-type longitudinal recess on the next element.

Accordingly, the oval comb on both construction materials thus acts as a reliable retainer.

This is a technically difficult option that requires some skill.

On the laying basis in the prepared bowl, a transverse protrusion is left at the bottom, which must fully correspond to the longitudinal recess of the upper element. It provides reliable docking of two elements among themselves.

Residue-free corner joining methods

For the installation of a beam without the presence of residues, the “paw” method is often used, which is represented by variations:

• Butt;
• Key (wedges);
• Indigenous spikes;

butt

The most popular variant of fixation in the paw in the implementation is butt.

All elements are joined together and securely fixed with nails and special steel plates. Before starting work on docking, all ends must be carefully aligned.

This method is not suitable for the construction of baths and residential buildings, since the insufficient strength of the connection of the corners is characterized by high rates of heat loss.

The connection of the beam to the paw on the dowels involves the use of an auxiliary liner, which is made from solid wood.

Dowels or wedges ensure the strength of the joining of elements in the corners.

To use dowels in laying logs, special recesses are made that prevent possible displacement of the finished structure. Dowels are of longitudinal, oblique and transverse type.

Indigenous spikes

Such a mount is referred to as a warm corner. This option provides for the angular combination of individual wooden elements, provides additional strength, wear resistance and reduces heat loss of the finished structure.

Technology in this type of paw is performed as follows: a groove is prepared in one of the materials, and a spike of the appropriate size is prepared on the other.

When joining the elements, wood insulation is placed in the recesses - jute or felt. To increase the stability of the finished structure, it is recommended to alternate the angular placement of grooves and spikes and connect them with round dowels made of wood.

When using undercuts, fat tails, dowels for the installation method - tongue / groove, a prerequisite is the presence of vertically located slots, which are necessary for proper shrinkage of the walls.

The most reliable, practical and durable version of the T-shaped installation of corners is the dovetail.

Technically, it is similar to the main tenon, the difference lies in the shape of the protrusion and groove, which are presented in the form of a trapezoid.

The dovetail is represented by a paw joint, when recesses in the form of trapezoids located horizontally are made in the laying base. This ensures perfect docking of structural elements.

A feature of the dovetail fastening is that it is able to withstand extreme loads, has wear resistance to deformation.

If the dovetail is done correctly, it provides strength to the entire finished structure. Dovetail fastening is used in the construction of wooden log cabins, baths and other buildings.

Connections of this type are represented by the following types of spikes:

• Frying pan (in the form of a trapezoid with a symmetrical arrangement);
• Half pan (in the form of a rectangular trapezoid);
• Lock groove (insert);
• Straight groove (radical).

When constructing large buildings with long walls, building material is required to be built up to 3-4 times the standard length. This requires secure fastening of two separate elements along the length.

The following connection options can be used:

• In half a tree;
• Oblique lock;
• Thorn root or longitudinal type;
• Spike on dowels or dowels.

In this case, it is allowed to use metal and wooden fasteners to fix the elements together along the length. The most durable is the fastening with the help of special protrusions on the dowels. It provides for the preparation of recesses for the grooves on the end part.

After that, the beams are laid closely, and a hardwood dowel is driven into the existing recess.

Dowels can be of various shapes - trapezoids, rectangles, prisms, with teeth and a flat surface.

Longitudinal joining in half a tree is similar in length to a similar method of fixing at the corners. The strength of the structure is ensured by fixing dowels, metal brackets or plates.

When using root spikes for docking, grooves and protrusions in the form of a trapezoid are cut out at the ends, the same as in the dovetail method.

The use of angular and longitudinal options for joining beams in wooden construction should be approached thoroughly. This has a significant impact on the strength of the erected building and the durability of its cladding.

What is a dovetail joint?

Very often, novice developers ask what is dovetail and how to put it into practice? We are happy to explain all the most important aspects of this type of timber connection, i.e. connection of a bar in a dovetail.

In really timber docking can be produced in different ways, but the most efficient and elegant will be the so-called "dovetail". Its design is capable of rigidly preventing the penetration of direct air flows into the premises. In terms of strength, such a connection is considered the most reliable, since it is very rigid, it is impossible to break it even with a high deformation load on the building. Dovetail log houses can withstand a strong earthquake (tested in practice).

Properly felled (cut down) connection is very tight. True, wood is a natural material, and it tends to undergo natural thermal expansion. During the drying process, the timber can absorb moisture more than once and give it back to the atmosphere. Naturally, the percentage of moisture gradually decreases and, as a result, the natural shrinkage returns to normal. To increase the density of connections, in place timber joining use interventional insulation made of flax, jute or tow.

The dovetail docking has been tested for years and has a quality standard.

Using a dovetail as a timber connection, you will already partially solve the problem of heat loss through the walls of a house made of timber, because you will get a high-quality warm corner. The regulation for the use of this connection is established by GOST 30974 - 2002 “Angular joints of wooden block and log low-rise buildings. Classification, designs, dimensions. This fact is weighty and convincing, as we are still accustomed to trusting government agencies in the field of quality control and operational safety.

Dovetail Dovetail Application Options

Even despite some complexity of the work, to do dovetail connection not a problem. Here you need to make a dovetail template and mark the places washed down on it. The template must be made in advance from a sheet of tin or plastic. It is more convenient to cut with a chainsaw with a short tire.

We list in which options for joining the beam you can use the "dovetail":

1. The dovetail is effective when joining the timber along the length.

Docking timber along the length in the "Dovetail"

Dovetail

2. The dovetail is often used to join the beam when the inner wall adjoins the outer one.

3. In the corners of a house made of timber, a half-dovetail connection is used (photos are clickable).

Corner connection of timber

Corner connection of a bar in a dovetail

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STUD JOINTS "DOVEL TAIL"

The dovetail stud joints are not only visually attractive, but also very durable. The ability to properly cut such spikes is a sign of skill that comes with experience.

When assembling furniture, fasteners are now widely used - screws, dowels, various ties. However, spike connections, including those on dovetail spikes, do not finally give up their positions. They are quite reliable and at the same time beautiful. On such connections, for example, the side walls of cabinet furniture with covers can be fastened. Breaking a dovetail joint by stretching is not easy. Therefore, it is often used in the manufacture of drawers. But we should not forget that the dovetail connection is resistant to such a load in only one direction.

Chipboard parts are not suitable for dovetail joints: this material is too loose. In one way or another, plywood, boards or furniture panels are suitable here.

Dovetail spike shape

If you look at the connection from above, you can clearly see that the "dovetails" are fan-shaped spikes at the end of one of the parts. The sides of the spikes are beveled inward with a slope ranging from 1:5 - for "rough", but strong connections used when rallying softwood parts and furniture panels, to 1:8 - for hardwood parts. The connection on the latter looks more attractive. And you need to know that with a smaller slope, the connection under load can disperse, and with a larger one, the spikes can collapse.

In the finished connection, the “teeth” that engage with the spikes are clearly visible. The slope of the spikes must exactly match the slope of the "teeth".

There should always be "teeth" (and not halves of spikes) in the connection along the edges -

this prevents buckling of the connected parts.

Another factor that affects the appearance of joints is the distance between the dovetails. In principle, the following rule applies: the wider the dovetails (thorns) or the greater the distance between them, the better. However, there is a limit to everything, besides, products come in different sizes (for example, a chest and a box), and one should not forget about the strength of the connection.

Marking spikes

The preparation of parts begins with trimming (their thickness does not have to match), and then mark
the position of the spikes and "teeth". It is better for a novice master to give a small (1-2 mm) allowance in length.

Malka is used for marking. To adjust it to the angle of the slope of the spikes, for example 1:6, two mutually perpendicular lines are drawn on paper and from the intersection point they are divided into six equal parts. Connect the sixth mark on one line with the first mark on the other. The slope of the resulting diagonal will be 1:6. According to this sketch, Malka is exposed.

At both edges, parts with spikes outline the width of the extreme "teeth" and draw lines through these points parallel to the edges. Next to the detail diagonally
impose a tape measure or ruler and turn it until the size between the lines is divided without a trace by the desired number of spikes. These points are marked on the diagonal, and then, using a thickness gauge, they are transferred to the end of the part. As a result of these simple constructions, the positions of the centers of the gaps between the spikes are determined.

On both sides of the centers found, lay off the same segment (in our example, 3 mm). The distance between the ends of the segments will be equal to the minimum gap between the spikes. From these points, with the help of a bevel, finally, the spikes themselves are marked. The height of the spikes is marked with a thickness gauge placed on a thick

the tire of the part with “teeth”. Marking is done on both sides of the part.

If the part has a length allowance, it should be taken into account when marking. In this case, the length of the spikes will be slightly longer than required. Later, when the parts are connected, the excess is removed with an end planer.

When marking, all parts with spikes are marked with some conventional signs to avoid confusion.

thorn cutting

For cutting spikes and “teeth”, special tenon saws are used. When using a conventional fine-toothed rip saw, it will require additional preparation, in particular, to reduce the tooth setting (especially if the saw is new). To do this, the saw blade is placed with its entire surface on the touchstone and one or two times it is easily passed over it. The same is repeated, turning the canvas over to the other side.

When cutting dovetail spikes, the part is clamped in a vise. If there are two such parts (for example, the side walls of a drawer), the spikes can be cut into both at once.

Start cutting along the marking lines by tilting the saw back and at the same time guiding it with your thumbnail. When the cutting line is "caught", the saw is leveled and work continues until the part is sawn to the full height of the tenon (to the horizontal mark). Under no circumstances should this label be crossed.

Now you can remove the material between the notches that form the tenons. This operation is performed with a chisel. Having selected wood on one side up to half the thickness of the part, it is turned over and processed in the same way on the other side.

Next, proceed to cutting the "teeth". The part with “teeth” is clamped in a vise, the part with sawn spikes is placed on the end and fixed. Then the saw is inserted into the cuts and the end part of the part with “teeth” is cut. Finally, the “teeth” are cut in the same way as the “dovetails”. And in this case, sawing should not be done along the marked line, but in such a way that the teeth of the saw lightly touch it from the outside. In conclusion, the material between the "teeth" is removed with a chisel.

Before connecting the parts, it is necessary to eliminate possible irregularities and carefully bevel the inner edge on both sides of each tenon (especially on the outer ones). This will facilitate the operation of connecting parts, and in the finished product such a bevel will not be noticeable.

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Dovetail, detachable tenon joint (trapezoidal grooves), used in mechanical engineering and carpentry for reliable fastening of parts to each other. In this material, we will consider the manufacture of devices that facilitate the production of grooves in a tree using a manual milling cutter.

Do-it-yourself wood router accessories

The machine itself is a very ancient invention of mankind, descriptions of the principles of milling appeared in the 16th century, and the prototype of the machine was the invention of Leonardo da Vinci, who proposed rotating a round file to increase the processing of the product, which can be considered the first analogue of a cutter.

And already the American inventor Eli Whitney over the years of his life from 1765 to 1825 brought to mind all the scattered attempts to create a full-fledged machine, for which he is rightfully considered the creator of the first milling machine, although not all scientists agree with this statement.

And since the machine has such ancient roots, there are a great many devices for the manufacture of various parts, it is not possible to describe them all in the light of this material, and therefore we will consider only some of them, in my opinion, the most important and useful.

Universal device for tongue and groove connection

factory plate for making tongue and groove joints

It is used with a router for cutting the corresponding grooves and spikes, it is installed in a vise, and the part is pressed against the device with a clamp. Usually sold in stores.

appearance of the connection

Consider slot milling fixtures

Cut out the top piece, a 18mm plywood tabletop 40cm long and wide enough to handle the thickest piece you plan to cleat.

Cut two 5x10 cm bars, sawing them the same length as the top. In the future, the bars will play the role of clamping the workpiece and centering it relative to the groove in the tabletop. To prepare the top, draw a line through the center of the top, then cut a groove along the line from one end.

schematic representation of the tooling

note

The notch should be the same width as the copy ring you will be using with your cutter. The notch should be long enough to match the length of the longest slot you are going to cut.

Then mill two adjustment slots perpendicular to the center line. Finally, drill a viewing hole between these two slots. To assemble the entire structure, screw the bolts into the jaws and secure the top to the bars with wing nuts and washers.

To use our equipment, draw a groove on the workpiece and mark the center line on it. Loosen the thumbs and set the blanks between the bars so that the center line connects with the top line of the fixture, check that the edge of the blank is against the edge of the top.

Hold the lambs. Align the router bit with one end of the slot drawing, then mark guide lines on the top surface of the table along the edge of the router base.

How to work with snap-in tongue and groove

Repeat this one more time to mark the lines of the other end. Mill the slot at the bottom, starting the cut by aligning the base of the router with the first auxiliary line, and stop milling when the insert reaches the second auxiliary line.

The main requirements for any prefabricated wooden structure are: reliability, durability and aesthetics. To solve these problems, a wide variety of docking methods have been developed. One of them is the dovetail.

This connection is formed by spikes on one part and cut teeth on the second. Both elements have the shape of an isosceles trapezoid, reminiscent of a swallow's tail. With proper preparation, they engage precisely, forming a reliable structure.

Connection application

This fastening method is used in various areas where it is necessary to obtain a reliable fastening of two parts or to assemble a whole structure. For example, in mechanical engineering, dovetail studs are used to fasten blades on a disk in various compressors, in individual units of metal-cutting machines, and in optical devices to ensure accurate linear movement.

This type of fastening is most widely used in construction and furniture production.

In construction, when assembling wooden houses, dovetail elements (teeth and grooves) are made at the ends of the fastened logs. It is advisable to use it for a connection bar that has a rectangular shape. The dimensions of the groove and spike determine the reliability of the entire future structure.

In addition, in construction it is used in the production of various joinery products:

• window frames;
• windows, vents and transoms;
• doorways and doors themselves;
• interior partitions, arches, various recesses.

For rough connections, a scale of 1:5 is applied. It provides reliable contact especially for large parts. This scale is acceptable for soft woods. In hardwood structures, a scale of 1:8 is usually used. This contact looks more aesthetically pleasing. When choosing this parameter, it must be taken into account that at a small angle of inclination, under the influence of external load or internal stresses, the structure may disperse. Therefore, it is fixed with wood glue. When setting a large angle, the lower part of the spike is reduced, which can lead to its destruction.

Making a dovetail with your own hands

The use of a dovetail mount allows you to get beautiful and reliable home-made wood structures. Making a dovetail is easy. However, for the production of high-quality teeth and grooves, it is necessary to have certain skills in carpentry and have the necessary tools.

The sequence of self-manufacturing of such a connection is reduced to the following list of operations:

1. Production of markings for future spikes. Before marking, determine the number of teeth (this value depends on the geometric parameters of the workpiece). With the help of a thickness gauge, a line of so-called shoulders is drawn. Marking is done on all four faces. Using a special template, markup is applied on the end and side surface. To avoid errors when sawing, the areas to be removed are marked with a special marking or color.
2. Cutting spikes. It is advisable to fix the part to ensure the accuracy of the cut. If it has large dimensions and weight, it is necessary to ensure its immobility and only after that proceed with cutting. First, cuts are made to the value of the marked shoulders. The main condition for the work is to maintain the perpendicular position of the saw with respect to the surface of the butt. To prevent the saw from drifting to the side, experienced carpenters use various guides, such as a carpenter's square.
3. Removing gaps. This procedure is performed in two ways. In the first case, a manual or electric jigsaw is used. The second uses a chisel and a hammer.
4. Markup of elements. Produce the marking of the angles of inclination of the teeth and grooves. The amount of this slope depends on the selected ratio. To obtain the same angles, a piece with sawn spikes is used as a template.
5. Sawing grooves. This procedure is similar in manufacturability to the process of removing gaps. To obtain high-quality results, it is necessary to ensure the fixation of the part and accuracy when cutting. Particular attention should be paid to the removal of the allowances provided.
6. Preliminary adjustment and assembly of the structure. This operation is necessary to check the accuracy of the manufactured spikes and grooves. With the help of pre-fitting, it is possible to identify possible defects. This will allow them to be eliminated or measures taken to ensure reliable fastening. Fitting should be carried out carefully without unnecessary effort and distortion, so as not to break the teeth. They should slide into the spikes smoothly. If necessary, grind with sandpaper.
7. Final assembly and gluing of the structure. After checking, glue is applied to the contact surfaces of the teeth and spikes. Glue is chosen depending on the weight and dimensions of the product. Modern manufacturers offer a fairly wide range of such products (different chemical composition, for different types of wood, conditions of use). To ensure reliable bonding, the parts are fixed with clamps and left to dry completely.

Tools and materials

The dovetail fastening method is used in the independent manufacture of wooden products in industrial enterprises. The possibilities of a home workshop are limited, therefore, for the high-quality manufacture of such a mount, the following tools and equipment are needed:

• saw with fine teeth (usually a back saw is used);
• jigsaw;
• chisel (it is desirable to have several with different widths of the cutting edge);
• a hammer;
• marking tool (ready-made templates, thickness gauge, joiner's square);
• construction pencil (sometimes a marker is used);
• carpentry knife.

If the workshop has power tools, they will facilitate the solution of the task. May be useful: an electric drill, a jigsaw or a vertical saw with fine teeth.

To make the connection, you can use a manual milling cutter. In addition, if a permanent assembly of wooden parts is planned, special devices are developed that allow marking and serve as guides when cutting.

In furniture and woodworking industries, teeth and grooves are cut on special machines. These include:

• lamellar milling cutter;
• milling machine with nozzles;
• a special machine for the manufacture of dovetail fasteners;
• industrial patterns.

Making a dovetail with a router is much easier and faster. The machine allows you to maintain the specified dimensions with a high degree of accuracy.

Connection design nuances

When designing dovetail elements, the following characteristics must be considered:

• size and weight of each part;
• type of wood;
• the scope of the future design (it will help to take into account the applied loads and internal tensions of the wood);
• the number of required grooves and teeth;
• their shape and geometric dimensions (length, angle of inclination, base size);
• spacing between teeth.

Taking into account these nuances will allow you to get a strong and durable mount. For the correct execution of the dovetail connection, the drawing must be made in accordance with established norms and rules. Too many elements can increase strength. This leads to a reduction in the size of each tooth, which can cause it to break during installation. In addition, it significantly increases the difficulty in manufacturing and leads to an increase in manufacturing time. Therefore, established ratios are used, for example 2:1 or 3:1.

After carrying out the preparatory work, it is imperative to carry out a preliminary check of the accuracy of the engagement. If mistakes were made, it is necessary to adjust each element (thorn or groove). After eliminating all the shortcomings, they begin to glue the parts.

State standards

The main standard that establishes the rules for the manufacture of fasteners for wooden parts is GOST 9330-2016. It sets the sizes of teeth, grooves, dowels of various types of assembly. The standard provides diagrams with samples of such fasteners. The rounding rules and symbols used in the drawings are indicated.

Download GOST 9330-2016