For various operations: drilling and chiselling. Tool for chiseling and trimming. Chiseling tools
Chiseling is the process of removing unwanted wood from a workpiece by inserting a chisel or chisel into it. Using chiselling, sockets, grooves and eyes are selected in the workpieces.
Chiseling tools
For chiselling, chisels and chisels (flat and semicircular) are used.
Carpenter's chisel consists of a steel blade, handle, ring and cap (Fig. 1.35, A). The chisel handle is made of hardwood or impact-resistant plastic. Chisels are manufactured in lengths of 315, 335 and 350 mm with blade widths of 6...20 mm. The sharpening angle of the chisel chamfer is 25...30°, and the sharpening angle of the side edges is 10°.
For selecting small pockets, stripping quarters, grooves, tenons, lugs, chamfering and fitting joints wooden parts use flat chisels(Fig. 1.35, b).
When processing rounded surfaces of workpieces and sockets, use semicircular chisels.
The length of the chisels is 240, 250 and 265 mm; width of flat chisels - 4...50 mm, semicircular - 4...40 mm; sharpening angle - 25...30°.
Preparing chisels and chisels for work
Chisels are sharpened on a mechanical sharpener and trimmed on a whetstone and whetstone, just like planer knives. The sharpening of the chisel should be one-sided with a chamfer and a rectangular blade. Flat chisels are sharpened in the same way as chisels, with a sharpening angle of the cutter of 25...30°. The blades of semicircular chisels are sharpened whetstone and a personal file.
Wood chiselling techniques
To obtain a through socket, first mark it on two opposite sides of the workpiece, and a non-through socket on one side. When performing through chiselling, place a board under the workpiece so as not to damage the workbench cover. Chiseling techniques are shown in Fig. 1.36. The chisel is selected according to the width of the marked socket, placed vertically near the nearest marking line (with a chamfer inward), retreating from the line at a distance of 1 ... 2 mm, after which the first blow is applied to the chisel with a mallet, and then the second blow is applied to the chisel tilted inside the socket. and cut off the first chip. Next, repeat the same thing and hollow out approximately 2/3 of the length of the nest. Then the chiselling process is continued at the opposite marking line. Then the workpiece is turned over and chiseling is performed on the opposite side in the same sequence. It is undesirable to cut off thick chips when chiselling, since as a result
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This deteriorates the quality of the workpiece.
Chisel cutting techniques
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When trimming and cleaning surfaces, the chisel is held with the palm of the right hand around the end of the handle, and the palm of the left hand is grasped around the blade of the chisel. With your right hand you press the end of the handle, causing the chisel to cut into the wood and move forward. Use your left hand to adjust the thickness of the chips removed and the direction of cutting. At the same time, to make cutting easier, the cutting edge of the chisel is placed at an acute angle to the wood fibers. Cutting techniques with a chisel are shown in Fig. 1.37.
Safety
Careless handling of chisels and chisels and failure to follow safety regulations can cause serious injuries. When working with a chisel and chisel, it is forbidden to cut towards yourself, in the air, with the part resting on your chest, or with the part on your knees. When cutting with a chisel, the fingers of your left hand should always be behind the blade. Before starting work, you need to make sure that the chisels and chisels are well and correctly sharpened. A chisel or chisel can be passed next to someone working only with the handle, and not with the blade forward. On wooden handles chisels and chisels should not be chipped, cracked, sharp corners and other defects that can lead to injury to the skin of the worker’s hands.
Helpful advice carpenter
To make it easier to hollow out a nest in the workpiece, you need to moisten the selected area by placing a rag moistened with hot water on it. After the top layer gets wet, it can be easily removed with a chisel. Then repeat soaking and hollowing out until the nest reaches the desired size.
Drilling wood
Drilling is a carpentry operation performed to obtain round holes for dowels, screws, bolts and other rod fastenings of wooden parts. Drilling also removes wood defects - knots, followed by sealing them with wooden plugs and glue. For drilling wood, drills are used: spiral, center, auger and countersink (Fig. 1.38).
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Drilling tools
Various types of drills are used for drilling.
Twist drills with conical sharpening (see Fig. 1.38, A) used for drilling wood along and across the grain, as well as at an angle to the surface of the part. Twist drills with a guide center and scorers (see Fig. 1.38, b) used for drilling wood across the grain. Twist drills have helical grooves on the surface of the shaft to remove chips from the hole. They choose deep and precise holes.
Center drills with a flat one (see Fig. 1.38, V) and a cylindrical head (see Fig. 1.38, G) used for drilling through and shallow holes across the grain in wood. Center drills with a cylindrical head are also used for drilling holes for hinges. Using center drills, shallow holes with a diameter of 12...50 mm are drilled. Such a drill consists of a rod with downward-facing undercutters, a cutting edge (blade) and a guide center (point).
During operation, the drill must be frequently removed from the hole to remove chips.
Auger drills(see Fig. 1.38, d) used for drilling wood across the grain. The diameter of auger drills is 10...30 mm.
Countersink drills, or countersinks(see Fig. 1.38, e), used for countersinking holes for screws and bolts.
Drill preparation to work
Drills are sharpened with fine-grained grinding wheels on a sharpener or by hand with files. When sharpening with a file, the hardness of the drill should be less than the hardness of the file. The cutting blade of drills with a guide center is sharpened from the back side, the scoring blade is sharpened from the inside, the guiding center is along the edges of the pyramid. For spiral drills with conical sharpening, the back edge is ground along the generatrix of the cone. Sharpening
done manually or using sharpening devices.
Hole drilling techniques
When drilling a hole, the drill must make two movements: rotational (clockwise) and translational (deep into the hole). To rotate the drill, it is better to use a brace with a ratchet (Fig. 1.39), which is an articulated rod in the middle of which there is a handle for its rotation. At the upper end of the rod there is a pressure head, and at the lower end there is a chuck for fastening the drill. The rotator should rotate left and right. The direction of its rotation is set by a ring-switch. You can use a hammer to tighten screws, bolts and nuts if you insert a screwdriver or socket into the chuck wrench. The drill can drill holes with a diameter of up to 10 mm. Drilling techniques using a brace are shown in Fig. 1.40. In addition to the brace for manual drilling, they use mechanical drill(Fig. 1.41).
To perform drilling, the workpiece is fixed on a workbench, then the center of the hole is marked and pricked with an awl. Once the center of the hole is determined, drilling begins. Through holes in thick parts are usually drilled from both sides. In thin workpieces, one-sided through drilling is done with a backing board with reverse side. When drilling at an angle to the surface of the workpiece, first drill vertical hole to a small depth, and then the drill, without stopping rotation, is turned at the desired angle to the surface of the workpiece. When drilling at an angle, you can first
cut out the top of the socket with a chisel, and then drill.
Often, for drilling several holes, overhead templates are used, which have holes of the required diameter and eliminate marking. Templates (conductors), made of hardwood, are bars in which 2...3 holes are drilled, equal to the diameter of the drill. The conductors are secured to the workpiece with a clamp and holes are drilled to the required depth. The resulting holes must have an exact size, and their axes must be strictly perpendicular to the top surface of the workpiece. When drilling wood, you need to use properly sharpened drills without cracks or defects. The drill should be fed into the hole easily and smoothly.
In order to make holes, sockets, eyes and tenons, you need not only a drill, but also slotting tool.
To perform this type of carpentry work, chisels and chisels are most often used.
Chisels are used for joiner's and carpenter's purposes.
Carpenter's chisels are used to make furniture.
Bit
This tool is used for gouging holes, sockets, grooves, tenons rectangular section in wood.
The chisel is a block made entirely of steel High Quality. One end of the tool is sharpened and forms a blade, the other has the form of a pin onto which a hardwood handle is mounted.
The cutting parts of the tool vary in width and sharpening angle.
The total length of the tool is 315-350 mm, the width can be 6, 8, 10, 12, 15, 18 and 20 mm. Thickness - 8-11 mm. The sharpening angle is from 25 to 35°, blade length is 315-350 mm.
In order to chisel, you need to install the chisel with the chamfer facing inside the socket. The distance from the marking should be 1-2 mm.
With light blows of a mallet, the tool is deepened, removing pieces of wood.
Chiseling is carried out to the middle of the workpiece on both sides, if it is necessary to obtain through holes.
Chisel
The chisel is used for the following types works:
- cleaning grooves and sockets;
- chiseling nests in thin materials;
- obtaining small depressions;
- removing edges;
- trimming of adjusted parts;
- processing of curved holes in the surface.
Tool length varies from 255 to 285 mm, width - from 4 to 50 mm, thickness - from 2 to 4 mm, sharpening angle - from 15 to 30° ( soft material- 15°, cleaning of eyes and pockets of hard rocks, shallow chiseling - 30°). There are several types of chisels:
- flat;
- semicircular;
- thin/thick;
- figured (for turning).
Flat chisel
A flat chisel is used to cut rectangular recesses.
Characteristics of a flat chisel:
- blade width - from 4 to 50 mm;
- chamfer thickness - from 0.5 to 1.5 cm.
Semicircular chisel
Semicircular chisels are somewhat thinner than flat ones. They are used for cutting round holes or recesses, leveling the surface of semicircular recesses, and obtaining smooth lines. Handles for chisels and chisels are made from hardwood.
Characteristics of a semicircular chisel:
- canvas thickness - 2-3 mm;
- blade width - from 6 to 40 mm;
- blade length - from 255 to 285 mm;
- sharpening angle - from 10 to 25°.
The rules for sharpening and straightening chisels are the same as for plane metal plates. Semicircular chisels are distinguished:
- along the radius of the circle;
- according to the depth of penetration of the chisel into solid wood;
- according to the width of the canvas.
Based on this, semicircular chisels are divided into:
- cool;
- sloping;
- deep (cerasics).
Angle chisel
This chisel is used for sampling wood to obtain precise geometric recesses. Characteristics of the corner chisel:
- the angle between the blade chamfers is from 45 to 90°;
- blade width - 4-16 mm.
Cranberry chisel
A chisel is used to sample wood if it is necessary for the bottom surface to be flat, and also if it is impossible to use other tools in the resulting recesses.
It differs from all of the above chisels only in the curvature of the blade.
Cranberry chisels can be straight, semicircular, or charcoal.
These types differ:
- according to the width of the canvas;
- by radius size;
- according to the depth of chamfering when sharpening.
Cutter, which removes chips during linear mutual movement of the cutter and material, is called planing (for horizontal cutting) or slotting (for vertical cutting).
The nature of the work of planing and slotting cutters is the same. Both during planing and chiselling, the cutter cuts only during the working stroke. At the same time, at the moment of the beginning and end of each stroke, shocks occur that adversely affect the operation of these cutters. Planing cutters or lobe cutters are representatives of the groups: planing tool or slotting tool.
Planing tool (planing cutter)
Planing cutter, as a representative of the group - planing tool, compared to turning, it works under more difficult conditions, since it always enters the processed material with an impact and experiences uneven stress due to changes in cutting forces.
During the cutting process on longitudinal planing machines, the table, together with the workpieces installed on it, moves along the fixed cutters, so here we have to deal with large inertial masses. This circumstance forces the use of reduced cutting conditions, especially in relation to speed, not only for cutters made of high speed steel, but also for cutters equipped with carbide. Planing cutter There are: pass-through, scoring, cutting and special grooved.
Slotting tool (gear cutter)
A gear cutter working by the rolling-in method belongs to the group - slotting tool. The cutter is a gear that engages with the workpiece, but at the same time, performs the cutting process as a result of the vertical reciprocating motion it receives, similar to a slotting cutter. When the cutter operates, the meshing of two gear wheels is reproduced. This type of slotting tool cuts cylindrical gears with both straight and oblique teeth of external and internal gearing. According to GSOT, they are intended for processing wheels with a profile angle of the original contour of 20? according to GOST. Usually dolbyak It is used for cutting wheels with involute gearing, but it can be used for processing parts with an arbitrary repeating profile.
Dolbyak, as a representative of the group - slotting tool, according to GOST they are manufactured in five types and three accuracy classes. The first type is a straight-toothed disk dolbyak. It is made with a nominal pitch diameter of 75, 100, 125, 160 and 200 mm. The second type includes a helical disk cutter. It is made with a pitch diameter of 100 mm and helix angles of 15 and 23 0.
The third type includes a cup-shaped straight-toothed cutter with diameters of 75, 100, 125, 50 mm. The fourth type includes a tail spur cutter with a nominal pitch diameter of 25 and 38 mm. The fifth type includes a tail helical cutter with a diameter of 38 mm and a helix angle of 15 and 23 0. In addition to the types of slotting tools listed above, there are gear-cutting straight-toothed disc cutters for spline joints with an involute profile.
A slotting machine designed for working on metal is equipment that can be used to process hard to reach places V metal parts. The main purpose of such equipment, which falls into the highly specialized category, is to create elements of various profiles, which is carried out by removing metal. Along with professional ones, there are also homemade machines similar type, but the principle of their operation is practically the same.
Features of slotting machines
Both professional and home-made slotting machines consist of the same structural elements, which allow such equipment to effectively perform all the functions assigned to it. The basis of any slotting machine is the frame on which the rest of the machine is mounted. structural elements: work table, cutter - a tool with sharp teeth, rocker mechanism, feed box, drive, which can be mechanical, electric and hydraulic.
Serial slotting machines, which are considered professional equipment, are equipped with a hydraulic drive. Working on such more advanced equipment, due to the presence of a hydraulic drive, is much easier and more convenient. A homemade machine for chiseling metal has more simple design, but at the same time is able to successfully cope with many technological operations.
The operating principle of the slotting machine is demonstrated in the video:
The design of professional slotting machines has a number of other important elements: cooling system, systems responsible for controlling the equipment and ensuring the uninterrupted operation of all components of the device. The hydraulic drive of the machine is located inside its frame, and programming its operation using a special system allows the slider, which makes reciprocating movements, to perform them according to precisely specified parameters.
A metal slotting machine allows you to perform a whole range of technological operations: forming keyways, grooves and splines on surfaces of both flat and shaped types, obtaining cuts and grooves in cylindrical and conical holes. This machine can be used to process external surfaces whose height does not exceed 320 mm, as well as internal ones with a depth of no more than 250 mm.
The movement of the working table of this equipment can be achieved using a manual or mechanical transmission, and can also be performed in a straight line or in a circle, which makes it possible to process gears and other metal parts on such a machine round shape. Unlike a professional one, a homemade machine can process parts only in two planes, which significantly reduces its functionality.
Working principle of a slotting machine
Processing of metal parts on a slotting machine is carried out due to the reciprocating motion, which vertical plane is performed by the slider and the cutter fixed in it. The working feed of the workpiece is carried out due to the movement of the table on which it is fixed.
The slotting machine can operate in two main modes: simple and complex. In the simple mode, a metal workpiece is processed point-blank, and the cutter, moving to the required distances, creates a series of holes that do not differ in shape and size. The complex mode involves processing angled holes and hard-to-reach surfaces located in the inside of workpieces. Such operations can only be performed using professional equipment. A machine made by yourself is not suitable for them.
Do-it-yourself slotting machines are optimally suited for equipping small industries and private workshops, where they can be used to process workpieces made of non-ferrous and ferrous metals. For large productions it is necessary already professional equipment, often equipped with computer numerical control (CNC).
You can get an idea of what the slotting cutters for the corresponding machines look like from the photo below:
Basic machine models
The most popular and widespread model of a metal slotting machine is the “GD”, which is represented by the 200 and 500 series. A more modern and functional slotting machine is the S315TGI model, which is also very popular among domestic producers. This machine, unlike more simple models and devices made by yourself, allows you to effectively perform a large list of technological operations on metal.
When choosing serial slotting machines, you cannot simply rely on promotional videos; you should take into account a number of important parameters. One of the most important characteristics is the maximum height of the workpiece that can be processed on the machine. Significant parameters of such a machine for metal are also: power, dimensions of the tool and the ability to adjust it, the presence of longitudinal and transverse stroke, permissible angle of inclination and speed parameters of the cutter. When choosing such a machine, you should also pay attention to its dimensions and weight, which affect its stability and ease of maintenance, and the equipment additional devices, which significantly increase the functionality of the device.
Making a slotting machine with your own hands
To make a homemade slotting machine with your own hands, at a minimum, you need a drawing of it. Any such equipment is, in fact, a vertical planing machine with manual drive. All structural elements of such a machine are placed on massive base(350x350x20 mm), which is also his work desk.
Based on this homemade machine a stand made of a steel rod with a diameter of 40 mm and a height of 450–500 mm is fixed. Cut through the entire height of the rack longitudinal groove, and at one of its ends there is a groove, which is necessary for its connection to the flange. Such a flange, which is a massive washer with one central hole and three fastening holes located around its circumference, is necessary to ensure reliable fastening of the rack to the base. The stand is inserted into the flange with its machined end and securely fixed in it using welded joint, and the flange itself is attached to the base of the machine using a threaded connection.
Drawings of a manual slotting machine, with which you can cut splines and grooves:
General scheme machine Console Mandrel-tool holder Support
A holder and a console are mounted on the console, between which a compression spring is installed. A fairly complex device is a console, the design of which consists of two hollow cylinders: a mandrel and a rack, connected by welding with a jumper ( square pipe section 60x60x2.5). In each of the cylinders, a hole is made with an M12 thread, which are necessary for the fixing screw that holds the console from turning (in the rack cylinder) and for installing the locking screw in the mandrel cylinder. From two opposite sides For the rack cylinder, it is necessary to weld axles for the tool feed levers, which are made from half-pins or screws with M12 threads.
The levers and rods of such a homemade slotting machine themselves are made of steel strip with dimensions of 30x8 mm. The levers and rods, hingedly fastened together with axle bolts, are placed on the axes of the mandrel cylinder and holder.
It should be immediately noted that on a home-made slotting machine, in one pass you can process a metal part to a depth of 0.2–0.3 mm.
We should also talk about the support of such a machine, which looks like a machine vice. Metal workpieces to be processed are mounted in a three-jaw lathe chuck, mounted on the upper movable platform of the caliper. With the help of such a support, which is reliable and easy to operate, the workpiece is fed in relation to cutting tool to the processing depth.
An example of another homemade product, made on our own.
Manual chiselling of wood. To form nests, grooves and eyes of rectangular cross-section in wood parts, chisels are used (GOST 1185-80).
Chisels distinguish between carpentry (Fig. 32, A) and carpentry (Fig. 32, b). The chisel consists of a blade with a blade at the end and a handle. To prevent the handle from splitting when hit with a hammer, a steel ring is placed on top of it. The handle should be tightly and securely fitted to the shank, and there should be no sharp corners or irregularities. The blades of chisels and handles are coated with colorless waterproof varnish.
Rectangular sockets with chisels are selected according to the markings, and when chiseling through sockets, the markings are applied on both sides of the part (Fig. 33, A), non-through - on one side (Fig. 33, b). Before chiselling begins, the part is placed on a table or
IN) G)
Rice. 32. Chisels and chisels:
A- carpenter's chisels, b- carpentry chisels, V- flat chisels, G- semicircular chisels; I- canvas, 2 - handle, 3 - ring, 4 - cap
workbench and secure it firmly. When hollowing out through sockets, in order to avoid damage to the table top or workbench, place a piece of defective board under the part. The chisel must match the width of the selected socket. If it is necessary to select identical sockets in several parts, they are placed in a stack and sockets are selected simultaneously in all parts.
Chiseling of nests begins like this: the chisel is set with a chamfer facing inward, retreating 1...2 mm from the marked mark, and with light blows of a mallet or hammer on the handle, it is deepened into the wood (Fig. 33, V) and again hit the handle with a mallet or hammer, and then, shaking it, take out the wood and thus continue chiseling (Fig. 33, d). It is necessary to deviate from the marking mark by 1...2 mm so that you can later clean this place with a chisel.
In order to increase labor productivity, reduce worker fatigue and comply with safety requirements when chiselling, it is necessary to take the correct position: you need to sit so that the hand holding the mallet or hammer passes over both legs.
When chiseling, make sure that the edges of the nests do not wrinkle. To avoid crushing the edges, the angle of the chisel should always be directed towards the middle of the socket.
When chiseling through nests, the wood is selected first from one side, and then, after turning the part, from the other.
Rice. 33. Working with a chisel:
A- sampling of a through socket, b- sampling of a non-through nest, V- position of the bit (initial and final) on the marking of the socket, G- the procedure for hollowing out the nest
Flat blades are used for cleaning and selecting sockets, grooves, tenons, and chamfering. chisels(Fig. 32, c), and for cleaning rounded tenons and processing concave and convex surfaces - semicircular chisels (Fig. 32, d) (GOST 1184-80). Like chisels, chisel blades are made of tool steel with heat treatment the working part and handles are made of wood of the same species as in chisels. Wooden handles are made from hardwood and must have a metal cap. Cutting edge(blade) must be sharpened. The shape and size of the collar should provide sufficient support for the handle. The collar should not have sharp corners. The handles are varnished.
In flat chisels, the blade is a flat, smooth strip ending in a sharp blade. The chisel blade acts like a knife, cutting or separating the wood fibers. When touching, hold the chisel right hand by the hand. The chisel should be moved along the grain as much as possible. When cutting with a chisel, press the end of the handle with your right hand, and press the blade against the wood with your left hand. The fingers of the left hand should not be in front of the chisel. The cuttings should be thin, soft and curled, not chipped.
Use semicircular chisels to process curved surfaces and hollow out curved holes. The sharpening angle of the chisels is (25 ±5)°. When working with a chisel, strikes with a mallet or hammer are applied strictly in the center. Working with a chisel is shown in Fig. 34.
G) d) e) and)
Rice. 34. Working with a chisel:
A- cleaning of cut areas, b- cross cutting, V- cutting along the grain, G- removal of a fractional chamfer, d- chamfering the end, e- end cleaning, and- cutting
from under the shoulder
To avoid injury when working with a chisel, you should not cut in the direction of the supporting hand towards you, while hanging, with the part resting on your chest, or when the part is lying on your knees. You should not leave chisels and chisels with the blade facing you or on the edge of a table or workbench, as you may be injured if the tool falls.
Mechanized chiselling. Electric shapers choose rectangular sockets, grooves, etc. The cutting tool of electric shapers is a continuous slotting chain, which is a set of links (cutters) hingedly connected.
Manual electric cutter IE-5601A (Fig. 35) has a built-in asynchronous electric motor with a squirrel-cage rotor, in which a drive sprocket is mounted at the end of the rotor shaft, driving a cutting chain stretched on a guide bar. The depth of chiselling is controlled by a stroke limiter. The head with the chain moves along guide columns installed on the base. The chain is tensioned by moving it using a stop screw and a ruler. The head lowers when you press the lever device - the handle, and rises automatically using cylindrical springs.
Depending on the size of the selected holes, rulers and chains of the required size are installed. The width of the groove obtained in one pass is equal to the width of the chain, and the length of the groove is the width of the guide ruler plus double the width of the chain. To select grooves of different sizes, a set of chains and rulers is required. When you-
By working a series of successive slots to a straight line, a groove of the required length can be formed. The depth of the selected hole is regulated by a stroke limiter installed on right size. When the head is lowered, it rests against the base.
Before starting work, you need to sharpen the chain well, then put it on the sprocket and ruler of the electric shaper. The electric cutter is installed so that the circuit is located above the socket that is selected. The material or part being processed is placed on the table and firmly secured. It is prohibited to work with an electric shaper if the part is not secured or is suspended.
Electric cutter IE-5601A:
/ - chain, 2 - guide column with spring, 3 - shield, 4 - electric motor, 5 - casing, b - lever device (handle), 7 - screw, 8 - guide ruler, 9 - base
After turning on the electric motor by pressing the lever device (handle), the electric shaper is lowered down along with the ruler and the chain stretched on it. The chain must be lowered evenly, without jolts, so that it penetrates the wood gradually. The chain feed speed depends on the size of the sockets selected and the hardness of the wood being processed. When the chain leaves the socket, you must ensure that there are no nicks or tears on the edges that occur when the chain is quickly removed from the socket. The rubbing parts of the electric shaper must be coated with lubricant.
At the end of the work, the chain, sprocket and guide bar are washed in kerosene and lubricated with machine oil.
The electric shaper can be used as a stationary machine by attaching it to the table so that the guide ruler with the chain is perpendicular to the plane of the table, and the plane of the ruler is parallel to the edge of the table.
If the body of the electric shaper becomes very hot during operation, it is necessary to loosen the pressure and unload the electric motor, change the blunt chain or loosen the chain tension. If the chain shakes, you need to tighten it. In the case when the chain or ruler gets very hot, you need to adjust the chain tension and eliminate possible distortions of the ruler. If during chiselling you get small chips in the form of chips, install a new chain. If the socket or groove turns out to be oblique during the chiselling process, it is necessary to align and strengthen the ruler extending to the side.
When working with power tools, you must wear safety glasses. The body of the electric shaper must be grounded.
4 Joinery, carpentry and parquet work
Rice. 36. Hand drills and drilling tools:
A- feather drill, b- center drill, V- screw drill, G- twist drill, d- rotation, e- drill, and- drill, s- gimlet: / - pressure head, 2 - crank rod, 3 - pen, 4 - switch ring, 5 - ratchet mechanism, 6 - cartridge, 7 - head, 8 - threaded handle, 9 - steel rod, 10 - cartridge, 11 - trimmer, 12 - center (point)
Manual drilling of wood. Round (cylindrical) holes for round tenons, dowels, bolts are selected with drills consisting of a shank, a rod, a cutting part and elements for removing chips. For drilling, feather, center, screw, and spiral drills are used.
Feather drills(Fig. 36, A) have a groove shape; they are used to select holes mainly for dowels. The groove also serves to eject chips. Due to the fact that it cannot completely throw the chips out, it must be removed from the hole frequently to avoid overheating. Therefore, the holes are unclean and not accurate enough. Drills have a length of 100... 170 mm, a diameter of 3...16 mm with a gradation of 1...2 mm.
Center drills(Fig. 36, b) drill through and shallow holes across the fibers. Drilling deep holes with these drills is difficult due to poor chip ejection. Drills work in one direction only. The drill is a rod ending at the bottom with a cutting part, consisting of a trimmer, a blade and a guide center (point). The diameter of center drills is 12...50 mm, length depending on the diameter - 120... 150 mm. When working with these drills, you need to apply pressure, otherwise they will not penetrate the wood.
Screw drills(Fig. 36, c) are used for drilling deep holes across the fibers. The end of the drill has a fine thread screw. When drilling with them, the holes are clean, since chips are easily removed through the screw channels. Drill diameter 10...50 mm, length 40... 1100 mm.
Twist drills(Fig. 36, G) Depending on the shape of the cutting part, they are available with conical sharpening (GOST 22057-76) and with a center and scorers (GOST 22053-76). To remove chips, the rod has grooves arranged in a helical direction
lines. Drills with a center and a scorer are produced with a diameter of 4...32 mm, and with a conical sharpening - with a diameter of 2...6 mm (short series) and 5...10 mm (long series).
The drills are driven by a brace and a drill bit.
The rotary hammer is used for drilling holes when performing carpentry and formwork work, and also used for tightening and unscrewing screws for glass and other types of work.
Rotator with ratchet(Fig. 36, d) It is a cranked rod, in the middle of which there is a handle for rotation. At one end of the crank rod there is a chuck for fastening drills, at the other there is a pressure head. The ratchet should rotate left and right, with the direction of rotation set by the switch ring. The chuck jaws must ensure that the tools are securely secured. The hammer can be used to tighten bolts and screws, for which socket wrenches (square or hexagonal) and screwdrivers are inserted into the chuck. The brace can accommodate drills with a shank diameter of up to 10 mm. To tighten the screws, screwdrivers are inserted into the brace. The rotator, consisting of a crank rod, a four-jaw chuck, and a switch ring, is made of structural steel. All parts of the brace have a protective galvanic coating.
Holes with a diameter of up to 5 mm are drilled drill. Drill (Fig. 36, e) It is a rod with a screw thread on which a handle is attached. At one end of the rod there is a chuck for installing drills, and at the other there is a head. The rod, and with it the drill, is rotated by moving the threaded handle up and down.
Used for drilling deep holes auger(Fig. 36,g), which is a rod with an eye for a handle located in its upper part, and with a screw drill at the other end (in the lower part).
Shallow holes in hardwood for screws are drilled with a gimlet(Fig. 36, h), having a diameter of 2... 10 mm. To avoid splitting the wood, the gimlet is periodically removed from the hole and cleaned of chips.
When using drills, holes are selected according to markings or templates. The center of the holes is pre-pierced with an awl. Before starting work, the drill must be sharpened well with a file with a fine notch or on a special machine, and then firmly secured in the chuck of a brace or drill. Drilling techniques are shown in Fig. 37.
When working, you need to ensure that the axis of rotation of the brace or drill coincides with the axis of the hole. When drilling vertical holes, hold the pressure head of the brace with your left hand and rotate the handle with your right.
Deep through holes are drilled according to the markings from two hundred
Rice. 37. Techniques for drilling material with a brace: A- horizontally laid, b- a workbench fixed vertically in a vice
ron details. When drilling holes on one side of a part, before exiting to the other side, the pressure on the pressure head of the brace must be loosened so that a chip, flake or crack does not form in the part. Place a board under the part in which the holes are drilled.
They work with a brace like this: place the workpiece-part on a workbench and mark the hole point. Then the handle of the brace is covered with the fingers of the right hand, and the pressure head with the fingers of the left hand. When drilling, press the head with your left hand, and rotate the cranked rod with your right hand.
The rotary hammer or drill must not be held so that the drill is facing towards the person working. You only need to press the pressure head of the brace and drill bit with your hands. You cannot use drills that have cracks or other defects.
When drilling is of poor quality, the following defects occur: the size (diameter) of the hole is not maintained, caused by the beating of the drill due to improper fastening of it in the brace; torn surface of the hole - when drilling with a dull or improperly sharpened drill.
Mechanized drilling of wood. Used for mechanized drilling manual electric drilling matires, consisting of a housing, an electric motor, a gearbox, a switch with a trigger drive, a current-carrying cable and a plug connection. At the end of the spindle there is a chuck for fastening drills.
For drilling holes with electric drilling machines, twist drills are mainly used. Before work, the machine is carefully inspected and checked, after which a drill is inserted into the chuck and firmly secured, and then the electric motor is turned on by pressing the trigger. Within 1...2 min
running idle; If the electric motor is working normally, start working.
When drilling holes, the pressure should be uniform; when making through holes at the end of drilling, the pressure should be slightly loosened to avoid jamming.
If the electric motor does not work when turned on, there is no voltage or the switch is faulty. If the gearbox heats up excessively, check the presence of lubricant. If, when you touch the body of the drill, there is an electric shock, check the grounding.
For screwing screws, bolts, nuts, screws use electric screwdriver IE-3601B. They can screw screws with a diameter of up to 6 mm.
When performing carpentry work, it is advisable to use an individual set of hand tools IN-18 for a construction carpenter, which includes a carpenter's hammer, axe, pliers, hacksaws, a brace, planes with a single and double knife, a chisel, a plumb bob, a wooden mallet, a saw set, flat chisels, screwdriver, carpenter's chisel, screwdriver for Phillips screws, triangular file, rack planer, builder's level, square, sanding block, folding wooden ruler. The working tool is placed in a hand-held wooden case measuring 535 X 450 X 115 mm. Set weight 10 kg.
Control questions.1. Tell us about the workplace of a joiner, carpenter and the structure of a workbench. 2. Name the main elements of the cutter. 3. Tell us about the cases of cutting. 4. What factors influence the production of a cleanly finished wood surface? 5. Tell us about the purpose and methods of marking. 6. What tools are used when marking? 7. What templates are used for marking? 8. What types of log cuttings are there? 9. How is a log processed with 2, 3 and 4 edges? 10. What saws are used for hand sawing? 11. Tell us about preparing saws for work. 12. Tell us about the techniques for working with hand-held power saws. 13. What tools are used for manual planing? 14. Tell us about hand planing techniques. 15. What is the purpose of a manual electric planer? 16. Name the techniques for working with a chisel and chisel. 17. What are the basic safety rules when sawing, planing, chiselling, and drilling? 18. Tell us about the methods of working as an electric shaper and electric drills.
