6. Production of cylindrical and conical parts with hand tools
Cylindrical parts, which in cross section have the shape of a circle of constant diameter, can be made from square bars. Bars are usually sawn out of boards (Fig. 22, a). The thickness and width of the bar should be 1 ... 2 mm more than the diameter of the future product, taking into account the allowance (reserve) for processing.
Before manufacturing a round part from a bar, it is marked out. To do this, at the ends of the workpiece, the center is found by crossing the diagonals and a circle is drawn around it with a compass with a radius equal to 0.5 of the diameter of the workpiece (Fig. 22, b). Tangent to the circle from each end, with the help of a ruler, draw the sides of the octahedron and outline with a thickness gauge lines 1 of the mated edges of width B on the sides of the workpiece.
The workpiece is fixed on the cover of the workbench between the wedges or installed in a special fixture (prism) (Fig. 22, e).
The edges of the octahedron are cut with a sherhebel or planer to the marking lines of the circle (Fig. 22, c).
Once again, tangents to the circle are drawn, lines 2 are drawn along the ruler and the faces of the hexagon are cut off (Fig. 22, d).
Further processing is carried out across the fibers with rounding the shape first with a rasp, and then with files with smaller notches (Fig. 22, e).
The cylindrical surface is finished with sandpaper. At the same time, one the end of the workpiece is fixed in the clamp of the workbench, and the other fit with sandpaper and rotate it. Sometimes the workpiece is wrapped with sandpaper, clasped with the left hand, and rotated with the right hand and moved along its axis of rotation (Fig. 22, f). Similarly, the workpiece is ground from the other end.
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The diameter of the part is measured with a caliper first on the part (Fig. 23, a), and then it is checked with a ruler (Fig. 23, b).
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The sequence of all these operations when obtaining a cylindrical billet from a square bar can be written in route map. In this map, the sequence (route, path) of processing one part is recorded. Table 2 shows a route map for the manufacture of a handle for a shovel. On fig. 24 shows a drawing of a handle for a shovel. Practical work Production of a cylindrical product 1. Develop a drawing and draw up a route map for the manufacture of a cylindrical or conical product, for example, shown in fig. eleven. 2. Mark and make a handle for a shovel according to the drawing (Fig. 24) and route map (Table 2). New terms: Caliper, route map. Questions and tasks. 1. What is the sequence for manufacturing a cylindrical and conical part? 2. How to measure the diameter of a part with a caliper? 3. What is recorded in the route technological map? |
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Turning cylindrical parts
On a lathe, products are machined, the contour of which can consist of several three-dimensional geometric shapes, which are called bodies of revolution . These figures are ball, cone, cylinder and torus(see fig. on the left).
The turning of parts on the machine is carried out with special incisors - turning chisels
. Unlike conventional carpentry chisels, they have elongated handles that allow you to securely hold the tool and make it easier to control.
The quality of processing is distinguished draft and finishing turning, the choice of tool depends on this.
For draft processing apply semicircular chisel(see fig. a), for finishing turning, trimming ends and cutting off parts - oblique chisel(see fig. 6 ).
At rough turning blanks (see fig. a) a semicircular chisel is moved along the handpiece. During the first pass, chips 1 ... 2 mm thick are removed by the middle of the chisel blade (see Fig. 6 , left). Further turning is performed by the side parts of the blade when the cutter moves both to the left and to the right (see Fig. 6 , on right). As a result of working with different sections of the chisel blade, the surface of the part is less wavy. After 2 ... 3 minutes of work, they check the reliability of fixing the workpiece - they press it with the center of the tailstock. For finishing, an allowance of 3 ... 4 mm (in diameter) should be left.
At fine turning(see Fig.) An oblique chisel is placed on the edge with an obtuse angle down. The shavings are cut off by the middle and lower parts of the blade.
The turning chisel is held with two hands when turning: one for the handle, the other for the rod. For the rod, the chisel is wrapped around the top or bottom. For rough turning, the first method is more often used, as the most reliable. The pressure on the chisel should be uniform and smooth.
For turning internal recesses of products using patron or faceplates(various containers, caskets, salt shakers, etc.) - first drill a hole in the center of the workpiece with a drill. Then, with a chisel with a semicircular end, excess wood is selected. Finally, to align the walls, use a chisel with a curved end (see the figure on the left).
For turning products with faceplates first make a blank in the form of a square. Diagonals are drawn on this workpiece and a circle is drawn slightly larger than the diameter of the intended product. With a saw, excess corners are cut to obtain an octahedron, which is screwed to the faceplate with screws. The faceplate is wound onto the spindle and checked to see if the workpiece clings to the handpiece. After that, the machine is turned on and the octahedron is turned to the desired diameter. Then the handpiece is installed parallel to the plane of the workpiece and its inner part is machined. Moving the handpiece, grind the outer side of the product.
The diameter of the product is checked caliper
or caliper
. Measurements should be made in several places along the length of the workpiece. Straightness can be checked with a ruler or a square in the light. 
Immediately after turning, the surface of the part is cleaned with a sandpaper attached to a wooden block (see Fig.). To brighten up the texture of wood, the surface of the product can be polished with a bar of harder wood. This operation is performed while rotating the part, as well as grinding.
When cutting the ends of the part, the oblique chisel is placed on the edge with an acute angle down and a shallow cut is made (see the figure on the left).
Then, stepping back a little to the right or left (depending on which end is cut), tilt the chisel and cut off part of the workpiece into a cone (see the figure on the right). This operation is repeated several times until a neck with a diameter of 8 ... 10 mm remains. Then the part is removed from the machine, its ends are cut off with a hacksaw. Ends are cleaned.
For the manufacture of a large number of identical parts used on a lathe conductors(limiters) for chisels or copier machines . The conductors are easy to make yourself and easy to install both on a turning chisel and on a handpiece (see the figure on the left).
The numbers indicate:
1. - emphasis;
2. - limiter of longitudinal movement;
3. - transverse movement limiter;
4. - turning chisel.
To obtain the desired contours on manufactured parts, specific chisels are sometimes used (see the figure on the right).
They are sometimes made specifically for a particular product or desired contour.
Below is an example of a product and the chisels that are used to make it.
For example, for the manufacture of a wooden ball, chisels are used, which are made to a specific diameter (see the figure on the left).
Without special chisels, the same ball can be machined with simple chisels, but for precise manufacturing it is necessary to make a stencil (template) with which you can measure the correctness of the spherical surface. 
The steps for making a stencil and turning are shown in the figure on the right.
Wood for turning is prepared not only by cutting out bars or pieces of boards, but also using dried tree branches, as well as gluing pieces of bars or boards (i.e. from segments) (see figure below). Often for turning such “block ”products use wood of different species.
Thanks to this, products that are very unusual in color and texture are achieved.
When working, follow these rules:
Lower the protective screen (put on glasses);
Check the operation of the machine at idle;
When processing the workpiece, smoothly bring the cutter;
Make sure that the gap between the workpiece and the handpiece does not exceed 5mm;
When performing axial drilling, secure the tailstock carefully;
While boring the inner hole, hold the cutter securely in a horizontal plane;
Control the dimensions and quality of processing with a completely stopped workpiece;
When finishing the part with sandpaper, fix it on a special holder.
Report all malfunctions to the teacher immediately, after turning off the machine!
Upon completion of work:
Remove the finished part from the machine;
Lay out tools and fixtures in specially designated places;
Clean up the workplace;
Report to the attendant when the work is completed.
During operation, the viewing screen on the machine must be lowered.
If the machine does not have such a screen, it is necessary to work in protective glasses.
The cutting tool is brought to the workpiece only after the spindle has gained full speed.
When the machine is turned on, it is forbidden to correct the workpiece and measure its dimensions, move the machine components.
After turning off the machine, do not brake the workpiece, chuck or faceplate with your hands.
Do not leave a running machine unattended.
At the end of the work, put the tools in the designated places, sweep the chips with a brush.
It is forbidden:
Turn on the machine without the permission of the teacher;
Work in the absence of a belt drive guard;
Use an unprepared workpiece;
Use a workpiece with chips, cracks, wet or rotten;
Lean on parts of a lathe;
Put tools and other items on the machine;
Stop the workpiece by hand;
Move away from the machine without turning it off.
>>Technology: Production of cylindrical and conical parts with hand tools
Cylindrical parts, which in cross section have the shape of a circle of constant diameter, can be made from square bars. Bars are usually sawn out of boards (Fig. 22, a). The thickness and width of the bar should be 1 ... 2 mm more than the diameter of the future product, taking into account the allowance (reserve) for processing.
Before manufacturing a round part from a bar, it is marked out. To do this, at the ends of the workpiece, the center is found by crossing the diagonals and a circle is drawn around it with a compass with a radius equal to 0.5 of the diameter of the workpiece (Fig. 22, b). Tangent to the circle, from each end, with the help of a ruler, draw the sides of the octahedron and outline with a thickness gauge lines 1 of the cut edges of width B on the sides of the workpiece.
The workpiece is fixed on the cover of the workbench between the wedges or installed in a special fixture (prism) (Fig. 22, e).
The edges of the octahedron are cut with a sherhebel or planer to the marking lines of the circle (Fig. 22, c). Once again, tangents to the circle are drawn, lines 2 are drawn along the ruler and the faces of the hexagon are cut off (Fig. 22, d).
Further processing is carried out across the fibers with a rounding of the shape, first with a rasp, and then with files with finer notches (Fig. 22, e).
The cylindrical surface is finished with sandpaper. In this case, one end of the workpiece is fixed in the clamp of the workbench, and the other is covered with sandpaper and rotated. Sometimes the workpiece is wrapped with sandpaper, clasped with the left hand, and rotated with the right hand and moved along its axis of rotation (Fig. 22, f). Similarly, the workpiece is ground from the other end.
The diameter of the part is measured with a caliper first on the part (Fig. 23, a), and then it is checked with a ruler (Fig. 23, b). 
The sequence of all these operations when obtaining a cylindrical billet from a square bar can be recorded in the route map. In this map, the sequence (route, path) of processing one part is recorded. Table 2 shows a route map for the manufacture of a handle for a shovel.
On fig. 24 shows a drawing of a handle for a shovel. 
Practical work
Production of a cylindrical product
1. Develop a drawing and draw up a route map for the manufacture of a cylindrical or conical product, for example, shown in fig. eleven.
2. Mark out and make a handle for a shovel according to (Fig. 24) and a route map (Table 2).
♦ Caliper, route map.
1. What is the sequence for manufacturing a cylindrical and conical part?
2. How to measure the diameter of a part with a caliper?
3. What is recorded in the route technological map?
Simonenko V.D., Samorodsky P.S., Tishchenko A.T., Technology Grade 6
Submitted by readers from the website
When marking, it is envisaged to apply the final dimensions of the parts to the prepared materials according to the drawing with an allowance for further processing. Obtaining high-quality and accurate blanks and parts largely depends on the accuracy of marking.
For marking and checking the accuracy of processing workpieces and parts, the following measuring and marking tools are used (Fig. 24):
A tape measure (Fig. 24, o) (GOST 7502-69) is a measuring steel tape with divisions printed on it, expressed in meters, centimeters, millimeters, enclosed in a round case with a diameter of 60-140 mm. The roulette tape has a length of 2, 5, 10, 20, 30 and 50 m.
The level (Fig. 24.6) (GOST 9416-76) is an aluminum case into which a sealed tube (ampoule) filled with alcohol is inserted. There is an air bubble in alcohol, which tends to take the upper position. Used to check the horizontal location of surfaces during work.
The levels have the following dimensions: width 22 and 25 mm, height 40 and 50 mm and length 300, 500 and 700 mm.
A folding ruler (Fig. 24, c) is a set of metal or wooden rulers with divisions printed on them with an accuracy of 1 mm. The rulers are connected to each other on hinges and are easily folded or assembled. The meter is used for linear measurements.
The square (Fig. 24, d) is a base, at which a ruler with divisions is mounted strictly at a right angle. Serves to check the correctness of the sharpened piece of iron in planing tools, the presence of a right angle on planed parts, the angle between two connected parts, etc.
Squares are made of metal or wood.
Erunok (Fig. 24, e) is designed for marking and measuring angles of 45 and 135 °. It consists of a block into which a metal or wooden ruler is inserted at an angle of 45 °.
Rice. 24. Tool for measuring and marking: a - tape measure; 6 - level; c - folding rule; g - square; d - erunok; e - wooden bevel; g - metal bevel; h - drag; and - bracket; to - thickness gauge; l - square - center finder; m - compass; n - caliper; o - tape measure; p - level with a plumb line; r - plumb.
1 - square; 2 - ruler; 3 - fastening bar; 4 - a cylindrical object in which it is necessary to determine the center.
Malka (Fig. 24, g) serves to measure the angle according to the sample and transfer it to workpieces - parts. It consists of a block and a ruler, hinged to each other, has a length of 337 mm.
The fence (Fig. 24, h) is a wooden block 400 mm long and 50 mm wide. At one end, the bar has a slight bevel, and at a distance of 1/3 from the edge, there is a protrusion into which a nail is hammered. Designed for drawing lines (marks) on the edges of the board, blanks.
The bracket (Fig. 24, i) is a wooden block, in which a quarter is selected approximately 1/3 from the edge. Nails are hammered into it with a certain step, with sharp ends of which lines are drawn. Used for marking eyes when manually cutting them.
The line is a metal fork, the sharp ends of which can be moved apart to the desired size.
The thickness gauge (Fig. 24, j) is a wooden block in which two wooden bars pass at a distance of 25 mm from one another. At their end, on one side, there are sharp hairpins (needles), with which risks are applied. Releasing the end of the bar by the block, set the required distance from the edge of the bar to the applied risk, i.e. marking. Designed for marking and applying marks parallel to one of the sides of the bar - details.
The center-finder square (Fig. 24, l) is a square 1, to which a ruler 2 is attached. In the upper part, the square is fastened with a bar 3. The ruler is fastened in such a way that it is in the middle of the fastening bar and divides the right angle of the square in half. Used to determine the center of cylindrical parts.
The compass (Fig. 24, m) is designed to transfer dimensions to workpieces, parts and to outline round markings.
Nutromer (Fig. 24, n) is used to measure the diameters of the holes.
The caliper is used to measure the diameters of round cylindrical parts, products.
A tape measure (Fig. 24,o) is a metal case with a spiral laid in it with a steel tape, on which divisions are applied. Designed for more accurate measurement and marking of any parts and blanks in width and shorter in length. A tape measure is made with a tape 1 or 2 m long.
A plumb line (GOST 7948-71) (Fig. 24, p) is a cylindrical metal weight, ending at one end with a cone. The diameter of the weight is 18-38 mm, the length is 63-200 m. It is suspended from a linen cord 3 or 5 m long, which is wound on a reel. Used to check verticality.
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Technology of manufacturing parts on a lathe. |
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The manufacture of any part begins with the selection of material. The selected material is cut into blanks. The size of the workpiece always exceeds the dimensions of the finished part by a certain amount (allowance). The size and shape of the allowance depend on the shape of the part, the technology of its manufacture. |
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Wood that is uniform in texture is best suited for turning. These are birch, linden, aspen, beech, elm, walnut. Turning parts on center machines
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Rice. 1. Sequence of part turning a - fixing the workpiece; b - fixing the workpiece incision; c- roughing with a reyer; g - finishing with Meisel; e- trimming (facing) of the workpiece. Turning internal cavities For turning internal surfaces, the workpiece is fixed only in the headstock of the machine, with a cam chuck, faceplate or tubular chuck.
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Rice. 2. Hollow turning a - on the faceplate; b- in a tubular cartridge. Work on lathes with a caliper On lathes with a caliper, processing is carried out with cutters fixed in a tool holder mounted on a movable caliper of the machine. Such machines, as a rule, have manual and mechanical feed along and across the machine. Turning cutters. According to the shape of the head, the incisors are divided into straight ones with a straight rod (Fig. 3 a) and bent ones with the rod bent to the right or left. According to the location of the cutting edge, right (Fig. 3d) and left (Fig. 3c) incisors are distinguished. The right ones move in the longitudinal direction from the tailstock to the front, the left ones from the front to the back. Through cutters (Fig. 3 a-c) are designed for turning, chamfering, through thrust cutters (Fig. 3 d) for turning and processing the formed end of the step. Scoring cutters (Fig. 3 e) serve to form a step at the end of the workpiece being processed, to process the plane of the end. Grooves on the outer and inner surfaces of the part can be obtained using groove cutters (Fig. 3 f, h). Cutting cutters are used for cutting (Fig. 3 g). For threading, a threaded cutter is used (Fig. 3 i). The shaped cutters are sharpened according to the shape of the workpiece (Fig. 3 j). |
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Rice. 3. Main types of turning tools The cutters are set so that the top of the cutter coincides with the center of the tailstock. The spindle speed should be 1200 rpm. Turning of cylindrical blanks. |
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Rice. 4. Techniques for processing cylindrical blanks The cutter is gradually fed forward until it touches the rotating workpiece, and in this position it is retracted to the right. The cutter is fed forward 2-3 mm along the limbus and the first working pass is made along the workpiece. Passages are carried out until a smooth cylindrical shape is obtained (Fig. 4 a). Having shifted the cutter according to the indications of the transverse feed dial to the desired size, a small test area is turned. If the measurement showed that the cutter is set to the desired size, then the surface is processed along the entire length from right to left (Fig. 4 b). After turning, the cutter is retracted. And they return to their original position. The same cutter cuts the end and ledges. The end face is cut until the cutter approaches the center of the part (Fig. 4 c). For turning rectangular grooves and ledges, a finishing (blade) cutter is used (Fig. 4 d). By moving it in the transverse direction and moving the caliper longitudinally, it is possible to machine a cylindrical surface with different diameters. Boring is used to select holes and internal cavities of parts. Boring is performed with a boring thrust cutter (Fig. 4e). The cutting edge of the cutter is set at the level of the spindle axis. When boring, the longitudinal feed of the cutter is alternated with its transverse displacements from the edge of the part to its center, removing material layer by layer from the wall of the cavity being cut out and leveling its bottom. Turning parts of complex shape is performed with shaped cutters |
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Rice. 5. Options for sharpening and installing shaped cutters Shaped cutters are made independently from strips of carbon or high-speed steel 3-5 mm thick, 10-20 mm wide and 100-120 mm long. The cutter is turned along the applied contour, hardened and sharpened (Fig. 5 a). The cutters must necessarily have a backing of the side faces so that they do not come into contact with the part during processing (Fig. 5 b). There are two options for installing a shaped cutter (Fig. 5c) for direct and reverse turning; during reverse turning, the cutter is turned over and a part with a reverse profile is obtained. Shaped cutters can be fed to the part in the transverse, longitudinal direction and at an angle to the axis of the part (Fig. 5d). To obtain parts of various complex profiles, you can use a composite cutter assembled from cutters with a thickness of 4-8 mm, with different sharpening. Their different combination allows obtaining various profiles (Fig. 5e). To obtain smooth shapes both from the outside and inside the part, a cutter with a cutting disc can be used. A disk 4-8 mm thick, 12-20 mm in diameter, a groove with a radius of 2-3 mm is machined along the edge of the disk. After hardening, the disc is mounted with a bolt on the mandrel and sharpened (Fig. 5 f). Machining a part on a copier. It is convenient to produce a large volume of identical parts using a copier. As a cutting tool, depending on the design of the machine, you can use turning tools installed in the machine support, chisels with an emphasis or disk cutters. |
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Rice. 6. Processing on a copier with a chisel and chisel |
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Rice. 7. Processing with a disk cutter on a copier.
Turning on a copier on a support machine
Rice. 8. Processing the part according to the copier
To make a copier, a part model is machined and sawn along the axis. The resulting section of the profile is transferred to plywood 4-5 mm thick and cut out (Fig. 8 a). Copiers can be made from metal using laser cutting.
The profile of future parts is fixed on the machine bed. A metal holder with a probe is attached to the cross slide of the caliper. The tip of the probe and the cutter must have the same profile (Fig. 8 b).
The first blank is preliminarily shaped into a cylinder with a diameter equal to the largest diameter of the blank, subsequent blanks can be made with a small allowance. First, the relative position of the workpiece and the copier is adjusted (Fig. 8 c), then the machine caliper is shifted to the left until the tip of the probe aligns with the line of the largest diameter of the part (Fig. 8 d). The cutter is fed forward until it stops against the surface of the workpiece, and the probe rests against the copier at the point of the largest diameter and is fixed in this position. Processing is carried out from right to left. The cutter is fed to the part in the transverse direction until the probe stops in the contour of the copier (Fig. 8. e). The value of the longitudinal displacement of the cutter per one transverse stroke is 1-2 mm. Cut marks are removed with sandpaper. The same copier can be used for turning parts of the same profile, but of different diameters (Fig. 8 f). A slight change in the angle of the copier gives a narrowing of the silhouette of the part. Long parts are sharpened on the copier in parts. Symmetrical figures are processed from the edge to the middle, then the workpiece is turned over and the second part is processed (Fig. 8g).
Cutting mode selection
The speed of the main cutting movement on lathes for different points of the cutting edge is different and depends on the distance to the axis of rotation of the workpiece. The average speed for the midpoint is determined by the formula:
V cp \u003d πD cp n / (60 1000)
where D cp - the average diameter of the workpiece, mm;
N- spindle speed, rpm;
The spindle speed is selected depending on the diameter of the workpiece; when installing a faceplate with a diameter of more than 400 mm, the spindle speed should not exceed 800 rpm.
The speed of the main cutting movement for soft wood is 10-12 m/s, for hard wood 0.5-3 m/s.
Longitudinal feed per spindle revolution for roughing 1.6-2 mm, for finishing no more than 0.8 mm. Cross feed per spindle revolution should not exceed 1.2 mm.
Machining parts on CNC lathes
CNC lathes have end mills as a cutting tool or are combined with end mills and disk cutters.
When processing a part with an end mill, you can get a different figured profile on the workpiece. The movement of the cutter and the speed of rotation of the workpiece are set using software, depending on the shape of the future part.
Rice. 9. Creating a sculpture on a CNC lathe
Machines with end and disk cutters allow you to speed up the process of turning workpieces. The disc cutter does the preliminary roughing, the end mill finishes.
Rice. 10. Processing the workpiece with a disk cutter
Rice. 11. Processing the workpiece with an end mill
After turning the workpiece, for final finishing and removal of cutting marks, it is treated with sandpaper, usually a piece of small width is used, which is moved in a taut state throughout the workpiece.
Rice. 12. Processing the workpiece with sandpaper
Literature:
1. Burikov V.G., Vlasov V.N. House carving - M .: Niva of Russia together with the Eurasian Region Company, 1993-352 p.
2. Vetoshkin Yu.I., Startsev V.M., Zadimidko V.T.
Wooden arts: textbook. allowance. Yekaterinburg: Ural. state forest engineering un-t. 2012.
3. Glikin M.S. Decorative woodwork on the machine "Universal" .- M .: Lesn. prom-st, 1987.-208 p.
4. Korotkov V.I. woodworking machines: A textbook for the beginning. prof. Education. - M.6 Publishing Center "Academy", 203.-304 p.
5. Lerner P.S., Lukyanov P.M. Turning and milling business: Proc. Allowance for students in grades 8-11. avg. school - 2nd ed., revised - M .: Education, 1990. - 208 p.
