Foot lathe. Mechanization after power supply, simple machines. Video: universal wood lathe

Foot-powered machines were invented by people long before electricity was discovered. On a similar machine, Russian Tsar Peter I mastered the basics of turning, and ancient masters used them to create their masterpieces of wooden architecture and shipbuilding.

Everyone young technicians We must now learn to mechanize our work, study the structure and operating principle of machines, first simple, then more and more complex. We must learn to build machines and use them. Our article should help you with this.

This foot-driven wood lathe was built by young technicians from Golobskaya high school Volyn region in the mid-60s of the last century, at the same time this article was published in the appendix to the magazine "Young Technician".

Let's look at the structure of the machine. It consists of a strong frame on which a base is fixed - two horizontal parallel bars, called parallels.
Rice. 1 General view homemade lathe.

On the left there are two racks on which they are mounted: at the bottom - a flywheel (flywheel), at the top, above the parallels, - an axis (spindle) and a stepped pulley (headstock), fixedly mounted.
On the right is the tailstock; it can move along parallels and is secured to them with a wedge or a bolt with a clamping nut. This headstock has a center - a horizontal rod, placed at the same height as the headstock spindle.
Between the front and tailstocks there is a stand - a tool rest, on which the cutter rests during operation. The tool rest can move along parallel lines. It is fixed in in the right position using a wedge or bolt with a clamping nut.
The spindle is driven by a flywheel and pedal. When you press the pedal with your foot, the connecting rod moves and the flywheel rotates. Through the belt, this rotation is transmitted to the pulley. Together with the pulley, the spindle and a piece of wood sandwiched between the spindle and the center of the tailstock begin to rotate. The chisel is rested on the tool rest and the wood is sharpened with it.

At what speed does the spindle rotate? This depends on the ratio of the diameters of the flywheel and pulley, which are cylindrical wheels adapted for belt drive. Let's turn to the laws of motion.

Two wheels connected to each other by a belt (Fig. 2) will have the same linear speed, since any point on the belt covers the same distance in each unit of time; consequently, any point taken on the circumference of each wheel moves with the same speed. It is further known that the circumference of the wheel is equal to 2╥R. If a wheel makes so many revolutions per minute, then each point on its circumference covers a distance equal to 2╥R 1 n 1 meters. But based on the first position, each point on the circumference of the second wheel must travel the same distance in the same period of time. Therefore, at the radius it will make a different number of revolutions. This is expressed by the formula:
2╥R 1 n 1 =2╥R 2 n 2

This leads to a very important point: two wheels connected by one belt always:

R 1 n 1 = R 2 n 2

n 1 /n 2 =R 2 /R 1

In other words, the number of revolutions per minute that two shafts make is inversely proportional to the radii of the wheels mounted on them, with which they are connected to each other.
Using this formula and knowing the number of revolutions of one of the wheels, it is easy to determine the number of revolutions of the other wheel. Let's assume that the first wheel (flywheel) makes 100 revolutions per minute, having a radius of 280 mm. You need to find out how many revolutions the second wheel (pulley) makes if its radius is 70 mm.
Let's substitute numeric values into the last formula and solve the problem for n 2

n 2 =100x280:700=100x4:1=400(revolutions).

The number 4:1, showing the ratio of the radii of the wheels, is called the gear ratio. It allows you to solve problems to determine the number of revolutions of one wheel if the number of revolutions of the other is known. To do this, it is enough to multiply the number of revolutions by the gear ratio.
These calculations will have to be resorted to when determining the dimensions of the stepped pulley.
Let's now proceed to preparing the machine parts. For this you will need good tree- dry, without cracks and knots, certainly hard rocks: oak, beech, in extreme cases, birch. Tree coniferous species no good
Prepare three bars for the racks 1 , 2 And 3 size 960x100x80 mm; three bars (stands 4 for racks) - 640x100x80 mm; two bars (for parallels 5 ) - 1400x120x40 mm; six bars (legs 6 for stands) - 275x100x80 mm; two strips 7 connecting legs - 1400x50x35 mm; one block for the tailstock 8 - 550x100x80 mm; two bars for a tool rest 9 And 10 - 250x50x20 mm and 400x60x50 mm; round roller 11 for a tool rest - with a diameter of 50 mm and a length of 320 mm; three blocks for the pedal 12 - 1000x80x40 mm, 960x80x40 mm and 530x80x40 mm - two clamping wedges 13 - each 20 mm thick, 250 mm long and 40 mm wide at one end, 50 mm at the other.
After all the bars have been prepared, proceed to marking (Fig. 1) and further processing them.

At the lower ends of the bars intended for racks 1 , 2 And 3 , make tenons measuring 100x80x30 mm At a distance of 315 mm from the upper ends, make cutouts for parallels 5 - 120 mm width and 25 mm depth. At a distance of 100 mm from the top ends of the posts 1 And 2 drill holes for the spindle 16 and make recesses for the ball bearings (according to their size). At a distance of 140 mm from the lower ends of the same struts, drill holes for the flywheel axis (crankshaft 17 ) and also make grooves for the ball bearings through which this axle will pass.
After this, into the bars 4 , intended for stands for racks, at a distance of 365 mm from their front ends, hollow out 100x30 mm sockets for the tenons of the racks on top, and two sockets for the spikes of the legs on the bottom side at a distance of 20 mm from the ends 6 size 60x30 mm. On bars intended for legs 6 , make tenons measuring 80x60x30 mm and cutouts for the planks 7 - 50 mm wide and 35 mm deep
A very important job - making an axis (spindle) 16 ) with stepped pulley 15 - for the front headstock.

The spindle can be made from a piece water pipe or a round steel rod with a diameter of 20-25 mm, with a thread at one end. This axis must rotate in ball bearings (Fig. 3). Therefore, it is best to first obtain suitable ball bearings, and only then, based on their internal diameter, select or grind the axle. If you cannot find ball bearings, then install sliding bearings. They can be made from sections of bronze or copper tube.
Pulley 15 it is better to turn it out of metal, but you can also make it out of solid wood. It fits tightly onto the spindle and is secured with a locking screw.
The pulley profile depends on which drive belt you use. For a flat belt a cylindrical pulley is made, for a round belt a grooved pulley is made.
The pulley does not have to be stepped, that is, consisting of two or three wheels of different diameters. On the described machine, a stepped pulley is installed in the expectation that over time an electric drive will be added to the machine. On a machine with a foot drive, you can install a single pulley.
Now you need to decide at what speed the spindle should rotate, and depending on this, determine the diameter of the pulley (or three cylindrical wheels forming a stepped pulley). Here you need to take into account the strength and structure of the machine and the dimensions of the parts that will be processed on it.
The average rotation speed for foot driven machines is approximately 300 rpm (machines with electric drive usually give 700-1500 rpm). During processing small parts the speed can be increased; When processing large parts, the spindle should rotate more slowly. At large number rpm, the blank can break out and hit the worker.
On the machine of the Golob young technicians, with a flywheel diameter of 570 mm, the pulleys have diameters of 140, 100 and 70 mm. This means that the gear ratios are approximately (rounded up) 4:1, 6:1 and 8.5:1. Assuming the flywheel rotates at 80 rpm, then with a gear ratio of 8.5:1 the spindle will spin at 680 rpm. This speed is too high for a machine with a foot drive. It is better to limit yourself to a pulley designed for a gear ratio of 4: 1 (or, if the pulley is stepped, then for gear ratios of 4: 1, 5: 1 and 6: 1). Using these numbers, determine the diameter of the pulley yourself.
The width of each of the three wheels forming the stepped pulley is 35 mm, therefore the total width of the pulley is 105 mm.
Flywheel diameter 14 - 570 mm, width 95 mm (other sizes are possible). To make a flywheel, you need to select and plan well dry boards 20-25 mm thick and glue three or four (depending on the thickness of the boards) square panels from them. To glue the shields you will need so-called clamps - the same clamps, but longer. Make them from blocks. Place the boards into two strands, having previously lubricated their edges (except the outer ones) with hot wood glue, and clamp them with two wedges, driving them one towards the other. All this is shown in Figure 4

Mark circles on the shields prepared in this way. In this case, you need to consider which belt will be used on your machine. If it’s flat, then all the circles should be the same diameter, but if it’s round, then the diameter of the middle (inner) circles should be about 30-40 mm smaller. Very carefully cut out the circles and put them on top of each other like this. so that the boards of the first circle intersect with the boards of the next circle, etc. Glue the circles together and screw them together for strength. But before you do this, think about how to weight the flywheel. There are several ways to do this.
The first way is this. In the inner circles, as close to the edge as possible, hollow out or drill several identical holes, placing them evenly around the entire circumference (Fig. 5, a). Fill these holes with lead. Instead of lead, you can put identical pieces of metal into them, such as large nuts.

To make the flywheel heavier using the second method, not solid circles are placed between the outer circles, but small circles in the center and rings around the circumference (Fig. 5, b). In this case, all the circles and rings must first be connected to each other, and then a hole must be drilled in the side wall and through it the hollow space inside the flywheel must be filled with dry sand. Do not forget to shake the flywheel so that the sand settles more tightly.
It is very important that the flywheel is balanced, that is, that the load is evenly distributed around its circumference
In the center of the flywheel, drill a hole along the diameter of the axle (crankshaft 17 ) Screw metal couplings on both sides of the flywheel; in one of them you need to drill a hole and cut a thread for a locking screw (that is, securing the flywheel to the axis). The flywheel mount on the axle is shown in Fig. 6.
Flywheel axis - crankshaft 17 - do according to fig. 1 from a steel rod with a diameter of 20-25 mm (you can select a long bolt of suitable diameter and saw off its head). It is difficult to bend such a shaft yourself; it is better to seek help from a forge or a mechanical workshop.

This shaft must rotate in bearings embedded in the racks 1 And 2 (Fig. 6) Connect the crank shaft with a connecting rod 18 with pedal 12 . The connecting rod can be made of both wood and metal. The structure of the connecting rod and pedal and their connection are clear from Fig. 1.
Now let's start assembling the machine.
First, assemble all three stands with stands, insert the spikes of the stands into the sockets of the stands, and then, after adjustment, you can glue them in place. Insert parallel bars into the cutouts of the racks 5 (often called a slide) and secure with bolts, nuts and washers. Distance between posts 1 And 2 should be 130 mm, between posts 2 And 3 - 1000 mm. Glue the spikes of the legs into the sockets of the stands 4 , and when the glue dries well, fasten them with strips 7 .
Remember that to fasten parts of the machine you can use wood glue, screws, small bolts, but not nails.
Assemble the pedal 12 and attach it (for example with door hinges) to the front strip 7 .
Insert into the recesses on the racks 1 And 2 bearings, place the flywheel between the struts and insert the crankshaft. Don't forget to put two steel plates on it to secure the bearings. Secure the flywheel with a locking screw and check whether it rotates strictly in one plane and whether the axis is skewed. The skew of the axis can be eliminated by wedging the bearings with small nails. When you achieve proper alignment of the axle with the flywheel, secure the bearings with steel plates and the shaft with two metal couplings with locking screws or studs. You also need to put washers under them.
Connect the crank shaft to the connecting rod 18 . You will also need studs and washers here.
Lubricate all rubbing parts with Vaseline and check whether the foot drive works well,
In the same order, assemble the parts of the headstock: insert the bearings into the recesses, place the pulley on the spindle, check the alignment and secure everything. To prevent the spindle from moving in the longitudinal direction, place two metal couplings on it, filling the gaps between the pulley and the bearings. Secure the couplings with locking screws.
Now put on the drive belt 20 and check the transmission of rotation from the flywheel to the pulley and spindle.
For cylindrical pulleys, take a flat belt 20-25 mm wide. For grooved pulleys, a twisted rawhide belt - supon - is used. The tension of the round belt is easy to adjust: just twist it harder.

Sew the flat belt with a thin rawhide strap. Sew the round belt with a staple made of thick steel wire (Fig. 7). To prevent the belt from slipping, sprinkle a little powdered rosin under it on the pulley and flywheel.
All that remains is to assemble tailstock and a handyman. These are very important parts, especially the headstock.
At the lower end of the bar 8 intended for the tailstock, make two cuts measuring 220x80x25 mm in such a way that after stripping this part of the block fits tightly between the parallels. In the same lower part, stepping back from the end by 60 mm, drill a hole for the clamping wedge. At the top of the block (at a distance of 100 mm from the end), drill a hole for the clamping screw ( 19 ) with a center and a handle.
The clamping screw can be a bolt with a curved end; its other end should be sharpened into a cone. It rotates in two nuts secured in a block (the same way you secured the bearings).
To make the tailstock more stable, screw two support bars to it. And so that the clamping screw cannot move away during operation, attach a stopper from a curved thick nail or a steel rod with a thread and a nut. All these parts of the tailstock are shown in Figure 8.

Install the mounted tailstock on the parallels (slide) so that the center of its clamping screw approaches the center of the spindle. The points of the centers should coincide; if this does not happen, it is necessary to adjust the position of the tailstock on the parallels.
On a bar 10 for the tool rest, make cutouts measuring 200x20x50 mm on both sides. Drill a 25x50 mm hole in the wide end of the block; insert a block into it 9 and secure with a small wedge. The top of the bar 9 cut at an angle (as shown in Fig. 1) Firmly screw a 220 mm long board covered with tin to it (for greater strength). In a roller 11 make two rectangular holes of 50X20 mm; the distance between them is 110 mm. A block is passed through the top hole 10 , a clamping wedge is inserted into the lower 13 .
Now you need to equip a spindle for fastening the workpieces different sizes. The auxiliary parts for this purpose are the fork, the faceplate and the cartridge.
It is better if the spindle is made of pipe. In this case, a flange that is screwed onto the pipe can serve as a faceplate. It is convenient to use a coupling as a cartridge, the so-called “transition” - with different diameters. The fork can be easily made from a short piece of pipe, screwed halfway into the coupling; its end must be flattened and processed with a file according to Figure 9.

In the same way, a fork, a faceplate and a chuck for a spindle are made from a steel rod or bolt. As a last resort, you can simply saw off the end of the spindle and turn it into a fork, but this is less convenient for work.
The good performance of a homemade machine depends on the accuracy of the parts, the accuracy of their fitting to each other, and the strength of the connections. It is clear that the machine should not wobble during operation and the spindle should not hit the bearings. The flywheel must rotate evenly and strictly in one plane. Finally, securing the tailstock and tool rest in any position must be rigid and reliable.
Therefore, it is necessary to correctly set the parallels, firmly connect them to the posts, and accurately adjust the lower parts of the tool rest and headstock to the distance between them. The entire frame must be connected very firmly. If the racks wobble in the grooves, then during operation the belt may jump off the pulley or, even worse, the workpiece will break out of the centers. Give rigidity to the entire system. It is possible that the most critical connections will have to be reinforced with strip steel angles.
For final finishing machine, clean all wooden parts with fine sandpaper and cover with drying oil and then with alcohol varnish. Paint metal parts with enamel or oil paint
We do not dwell on trifles and minor details, since we believe that the construction of a lathe, even the simplest one, should only be undertaken by those young technicians who already have known knowledge, skills and experience.

The construction of a machine opens up wide opportunities for independent design and improvement of individual parts and assemblies. For example, clamping wedges 13 can be replaced with bolts and clamping nuts. Such a replacement is shown in Fig. 10 When processing long objects, the tool rest can be replaced with a block screwed to the posts 2 And 3 at points “A” (Fig. 1). Instead of a foot drive, you can make an electric one by attaching an electric motor under the pulley.
If you cut a thread on the end of the spindle protruding to the left (that is, outward) and select nuts and washers, then you can put a small round sharpener or grinding wheel on it.

In the next article we will talk about cutting tools, used when working on a wood lathe.

We suggest that you familiarize yourself with the drawings and diagrams of a lathe with the simplest design, which was used even before the advent of electric motors. The design of the lathe is attractive in that it can be manufactured by almost everyone, does not have complex components and does not require any scarce materials. And the capabilities, despite the “antiquity,” are no worse than those of any purchased lathe: after all, all the beautiful examples of folk wooden art that we admire in local history and ethnographic museums were created on approximately such machines.

1 - flywheel, 2 - crankshaft, 3 - drive belt, 4 - machine stands, 5 - headstock drum, 6 - headstock shank, 7 - caliper, 8 - upper tie (caliper guide), 9 - tailstock head, 10 - tailstock (bolt), 11 - rack bearings, 12 - lower tie rod (pedal axis), 13 - pedal, 14 - pedal rod.

The first thing you notice when looking at the proposed machine is that it does not have any motor. The drive is foot pedal and a crankshaft, hingedly connected by a metal (although it can be wooden) rod. A flywheel is attached to the crankshaft, promoting uniform rotation of the workpiece, sandwiched between the shank of the headstock and the cone of the rear. For example, a massive wooden circle (cut from a trunk of suitable diameter) or a disk made of thick boards (in two or three layers), respectively processed with a hacksaw, files and sandpaper, is suitable as a flywheel.

From the flywheel, rotation is transmitted through a leather or rubber-fabric belt (or cord) to the headstock drum. Since the latter has the same diameter along its entire length, the change in the rotation speed of the workpiece depends only on the operation of the pressure pedal. If the drum is made in the form of a series of pulleys of different diameters, the desired speed can be obtained by simply throwing the belt. However, then you will need to come up with a device for tensioning the belt when transferring it from a larger pulley to a smaller one.

To connect the listed parts and assemblies into a single structure, wooden racks are used, which in turn rest on wooden thrust bearings. Both the racks themselves and the thrust bearings are made of identical boards 20-25 mm thick.

1 - rack bearing with a window for a tenon, 2 - rack end with a tenon.

The longitudinal strength of the structure is provided by the lower and upper ligaments. On one of the lower ones - the one that is longer, combining all three racks (made of pipe or block), the pedal is hinged. And above it, on the top link (a board, like the racks, but half their width), a support is installed on which the processing tool will rest: a chisel, chisel, file or grinding block. The caliper can move horizontally and be fixed in the right place thanks to the eccentric with a handle located below. All caliper parts are made of hard wood.

The caliper base is an H-shaped body; it can be made entirely or from bars. IN top groove a support for the tool (bar) is inserted, and the lower one slides along the bar of the upper tie of the machine. The eccentric that fixes its position is a metal disk with a square hole offset from the center; the same hole is in the handle bar. The axle rod included in them has the same square cross-section as the middle part of the headstock shaft, where the drive drum is installed. The head of the headstock ends with a tooth that holds the workpiece.

1 - support, 2 - H-shaped body, 3 - screws for fastening the support, 4 - eccentric clamping disk, 5 - eccentric axis, 6 - handle bar, 7 - handle screw, 8 - handle, 9 - upper tie bar of the machine.

The crankshaft is made of steel rod with a diameter of at least 10 mm. A bushing is placed on its shank for protection. wooden stand at the point of rotation of the threaded part.

1 - crankshaft, 2 - flywheel, 3 - strut, 4 - bushing.

1 - pedal, 2 - traction loop, 3 - tie rod bearings, 4 - pedal hinge hinge.

The connection of the racks with the thrust bearings and the landing of the pedal are clear from the drawings. The tailstock in the post hole can be without an additional protective sleeve, since its rotating part is only a conical attachment. The main part - the axis - is an M8 bolt with a wing nut and a washer that rests against the stand when the part is clamped; The end of the bolt is sharpened to facilitate rotation of the headstock (a steel ball can be used instead).

1 - thrust axis of the head (M8 bolt), 2 - thrust washer, 3 - adjusting wing nut, 4 - headstock head.

The workpiece must not be rectangular section, otherwise the inexperienced “turner” will not be injured for long, because the tool is not secured and is held only by his hands and the support of the caliper. Therefore, the latter should be applied to the cutting site gradually and very carefully. If you have to grind a block, you must first round it with a coarse file (you can use the same machine), and only after that use the cutters.

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Nikolay Mukhin - Master of metal and wood.

This page is an introduction to him, where his works speak for themselves. For about 24 years now Nikolai lives in Siberia, once arrived from Voronezh.

Technologies the creation of his machines is only an intermediate link on the way to Stalker-technological approaches to design. And here we are We especially emphasize this. However, this is already an opportunity to work independently in any place where there are no conventional energy sources. If desired, the Machines can be activated and from Water or Wind Drives or from any available sources Mechanical energy with the same belt.

And although they are created in a technologically dependent way, they are still capable of bringing a lot of benefits and being relatively durable.

Nikolay also has examples of the execution of Muscular (Muscular-driven or Foot-driven machines, otherwise - mechanical machines with a muscular drive) combined from metal, with frame parts made of wood.

When worn ball bearings, which can still happen sooner or later in the rotation units, can be relatively simply replace the bearings with birch bushings.

The mechanical transmission is a classic crank mechanism, V-belt and belt belt drives.

Nikolai’s machines, created back in 97, 98 still work in a taiga settlement, remote from roads and electrical networks. Personally, I drilled it myself metal 20 mm. with a drill 16 mm thick, he adjusted and sharpened the tool with the strength of one leg, and sharpened the wood. Moreover, we even managed to sharpen the metal with a hand tool, like in the old days, and cut the metal blade, made of self-hardening rapid, with disks made of simple 0.3 mm tin. steel 3.

People who come into contact with his muscular machines for the first time, trying them at work, take their breath away. Some people squeal literally words. Many say that they could not even imagine that it was possible to turn the machine with one foot under the load of a cutter or drill.

Watching this from the side, I whispered to Kolya: “You managed to make not just machines, but Mechanisms of change of Consciousness… This is their main role, to treat people from electrotechnocracy.” Kolya knows what I did too Pottery machine welded structure on birch bearings precisely for this purpose. So that no one would later say that this is nonsense. Let them try it in their work and base their opinion on fact, and not on speculation. Unlike ideas and illusions.

Lathe on wood with a muscular drive and crank-belt drive.

Drilling foot driven machine. Muscular drilling machine.

Leg Muscular Emery(Sandpaper) sharpening or as they also say Sharpening machine, and in common parlance - a sharpener with a factory-made abrasive.

Lesson topic. Mechanical Engineering.

Sewing machine with foot drive.

Lesson objectives. Familiarize yourself with the purpose and design of the foot drive,

organization of the workplace when working on a sewing machine

with foot drive.

Build knowledge about the rules safe work by car

with foot drive.

Learn how to operate a foot-operated machine.

Cultivate a caring attitude towards equipment,

attentiveness.

Develop coordination of arms and legs.

Equipment: workbook, threads, foot-operated sewing machine.

Progress of the lesson.

1. Organization of the lesson.

Checking students' readiness for the lesson.

2. Repetition of the material covered.

Oral survey.

Review questions:

1. What fibers are natural?

2. What two groups are natural fibers divided into?

3. What is called wool, fleece?

4. What is called natural silk?

5. What are the positive properties of wool and silk fabrics?

6. Name negative properties wool and silk fabrics.

7. How does thread shedding affect the cutting of products?

3.Learning new material.

Teacher's explanation.

Modern household sewing machines are produced with three types of inputs: manual, foot and electric. You are already familiar with a manually driven machine and know how to sew on it. A foot-powered machine differs from it primarily in that it is driven by the legs. It is faster, which allows you to reduce sewing time and increase productivity.

The foot drive has a pedal, which is driven into an oscillatory motion by the legs of the operator. This movement is converted into rotation using a connecting rod and transmitted to the drive wheel. . The rim of this wheel has a groove into which a round drive belt is inserted. The belt connects the drive wheel to the flywheel pulley mounted on the main shaft of the machine. The main shaft, rotating, sets in motion the working parts: needle, fabric motor, thread take-up, shuttle. For safety reasons, the drive wheel is covered with a shield at the front.

Since the pulley is 5 times smaller than the starting wheel, then for one revolution of the starting wheel (for one swing of the pedal) the pulley will make as many revolutions as it is many times smaller than the starting wheel. Disadvantages of belt drive are belt pulling, slipping, salting.

At the end of the work, the belt must be removed from the wheel.

Safe work rules.

When working on a sewing machine with a foot drive, you should take into account basically the same requirements and rules for organizing the workplace as when working on a machine with a manual drive.

When using a foot-operated sewing machine, pay attention special attention on the correct position of the arms and legs.

When threading a machine needle, do not hold itfeet on the pedals.

Do not wear the belt while the machine is running. While working, do not hold the belt with your hand, otherwise you may injure it with the paper clip.

4. Practical work.

Before you start working on a sewing machine with a foot drive, you need to learn how to use your feet correctly - rock the pedal evenly. The flywheel should rotate only for the person working.

The teacher shows correct landing behind the sewing machine, placing your feet on the pedal.

Students do exercises.

1. Machine on idling.

Set the car to idle (similar to how you did it on a manual car).

Place your feet on the pedal so that your right foot is slightly ahead of your left. Turn right hand the flywheel towards you and, working with your feet, rock the pedal. Press it smoothly, without jerking, with one or the other foot. Place your hands on the machine platform. To stop the machine, stop rocking the pedal and hold the flywheel with your right hand (fingers should be closed).

Repeat the exercise several times.

2. The machine is running.

Do the same exercise with the machine in working motion. Place a fabric folded in half under the presser foot and operate the machine without threading. Once you have mastered the correct movement of your legs, you can begin working on the threaded machine.

Questions for consolidation.

1. How should the light fall and the chair stand when working on a sewing machine?

2. Show me how to properly sit at a sewing machine and what should be the position of the arms and legs?

3. What mechanisms sewing machine Are they driven by the main shaft?

4. What are the disadvantages of belt transmission?

5. Analysis and evaluation of the lesson.

Analyze the lesson, mark typical mistakes, assign grades to all students.

Homework. Abstract.

The first machine that every craftsman feels the need for is a tabletop drill, or simply a drill. But after purchasing it or making it yourself, it soon turns out that you need to sharpen something, and a lathe costs an order of magnitude more. The temptation is great to make a universal lathe like the one in Fig. below:

One can only take off one's hat to the ingenuity, skill and accuracy of such masters. Yes, you can also turn wood on a metal lathe; Many of these benchtop lathes come with inserts in the spindle chuck to hold the wood workpiece. But - alas! – a homemade universal lathe will not hold precision on metal for long.

The point is not only that the cutting force of metal is many times greater than that of wood. The physics of metal cutting itself is completely different. In order not to go into the basics, even a cursory superficial review of which would require an inordinate amount of space, let’s take it and compare it: have you seen a metal cutter as sharp as a chisel or a piece of iron on a plane? And what happens if you cut down a tree with a chisel? The drill can still cope with both materials: there the cutting force is symmetrically concentrated on the working body itself. But as for the metal point, the requirements for the machine tool, the requirements for the machine tool for it turn out to be such that machine tool building became a separate industry long before the industrial era. The best machine-building plant He doesn’t make his own machines – he’s not up to the task. However, it is quite possible to assemble a wood lathe with your own hands, and in such a way that it will maintain the maximum achievable processing accuracy of +/–0.5 mm on wood for many years, if not decades. You still can’t do without 2-3 turning operations on metal (see below), but in this case they can be performed to order by a turner of 2-3 categories on a regular, not high-precision, machine, even if it’s a restored DIP. And, of course, you will need to buy a set of cutters for processing wood on a lathe, see figure. Everything else will not require any additional costs.

History and evolution

Further in the text you will come across technical solutions that are effective, but little known to amateur craftsmen, because... in industry, for one reason or another, they are not used or are used to a limited extent. However, they can simplify and facilitate the manufacture of a homemade lathe for wood processing so much that in some cases it will be possible to limit the use of power tools hand drill. The machine tool industry of the millennium is developing under the sign of solving the problem: how to make machine parts with an accuracy of, say, 1 conventional unit of length on a machine with an accuracy of, say, 0.2 of the same units? Etc., etc. To understand how technology came to such a life, it will be useful to briefly turn to history.

The ancestor of all machines for processing materials by rotation is a device with which Neolithic people made fire and drilled horn, bone, stone, etc. 1 per rice; in the latter cases, under a drill made of wood or bone, abrasive from wet quartz sand. The primitive Celts, using the same principle, invented a foot-operated lathe, pos. 2; the centers were made from sharpened, burnt stakes of hard wood. In England, this unit is still used by furniture makers. The forest is not cut down there block by block. Having bought a couple of scaffoldings for felling, the master then carries armfuls of finished legs, balusters, etc. to the track. In a craft of this type, the machine survived for approx. until the beginning of the 18th century, pos. 3, although the workpiece rotates back and forth in it and the master has to be additionally distracted to turn the cutter over.

IN Ancient Egypt Already in the era of the Middle Kingdom, a lathe with a bow drive was well known, pos. 4. The “motor” was, naturally, the slave. In the Russian village community (in the world), with its strong traditions of mutual assistance and mutual assistance, the bow lathe survived in the outback until... the 80s of the last century! Mass individual wood construction was in no way included in the five-year plans, but the Soviet leadership in the provinces turned a blind eye to unauthorized logging in limited quantities for their own needs or to unauthorized purchases of wild logs from timber industry enterprises for the universal Soviet currency with a strength of 40 vol. and a capacity of half a liter.

For fine and/or small work, a foot machine with a string and a bow machine were not suitable: there are always inhomogeneities in wood, and the workpiece itself was the flywheel - the damper of torsional vibrations. Master Theodore introduced radical improvements to the lathe in Ancient Greece approx. in 400 BC uh, pos. 6. He supplemented the foot drive, firstly, with a crank - now the workpiece rotated in one direction. Secondly, I made the centers rotating and equipped one of them with a grip to hold the workpiece. Thirdly, introduced into kinematic diagram heavy flywheel. Some machines of this design were in operation at industrial enterprises before the start of electrification of industry, pos. 7 – given the complete absence of social guarantees at that time, the labor of an unskilled helper was cheaper than the cost of maintaining a steam engine.

The electrified wood lathe (item 8 in the previous figure) has remained virtually unchanged since the end of the 19th century (see also figure below):

• a – motor rotor and other massive drive parts do not require the use of a separate flywheel;
• b – c chuck you can install different tips for various kinds blanks (see below) or drill;
• c – a tool rest with a rotating shelf-support for the cutter, mounted on a movable carriage, makes it possible to carry out a wide variety of working operations;
• d – tailstock with a rotating center allows you to bring the processing accuracy to the maximum possible on wood;
• d – the tailstock quill feed screw (see below) makes it possible to carry out complex processing of a workpiece into a part in one installation. During processing, the wood yields under the pressure of the holder and the center. If the tailstock is fixed rigidly, the workpiece becomes loose during processing. The machine has to be stopped and the blanks reinstalled, which in no way contributes to the quality of work.

What if there is no motor?

A non-volatile wood lathe can still be useful today; say, at a dacha or an unequipped construction site. Muscular strength is normal developed person sufficient for turning workpieces made from ordinary timber with a diameter of approx. up to 150 mm. In such a case, 2 options are possible (see next figure): a good old machine with a foot drive (the dimensions of its most important unit, the crank, are given at the top right); For more details about it, see below, and processing on trestles with manually driven tow rope (bottom right in the figure). You can’t round timber to the girth in this way, but it is possible to grind the support pillars of a porch, gazebo or canopy over a barbecue.

Make or buy?

The first question that needs to be resolved: since some mandatory costs (see below) are inevitable, are there any opportunities to purchase a wood processing machine without taking out a loan or cutting the budget? There are some, and they are very good.

If you come across the old UBDN-1 (on the left in the figure) or its modern analogues (in the center) at a reasonable price, don’t yawn! There is no need to convert anything at home: the motor is up to 350 W with double insulation of the windings. The machine plugs into a regular outlet; no grounding is required. And you will receive in one product:

1. Circular saw;
2. Electrojac for tool sharpening, etc.;
3. Jointer;
4. Disc grinder;
5. Horizontal drilling machine;
6. Lathe for wood processing.

Another option, most likely cheaper, but only for horizontal drilling and turning - a drill stand that turns it into a lathe, on the right in Fig. Drill bit beds for drills are almost peddled on the streets, but not everyone knows about lathes. Meanwhile, an electric drill as a drive for a wood cutting machine has serious advantages (see below), and a lathe with it will be no worse than a branded one. But much cheaper.

Note: it's better to start with a quick fix build a simple lathe and work on it a little. Wood turning skills are easy to develop, and how to quickly make a simple wood lathe, see the video:

Video: a simple homemade lathe

Main material

The next question is what to make a homemade lathe from? The answer seems obvious: made of metal, after all, the machine cannot be weaker than the workpiece? How did the primitives drill into stone with wood? How did the ancient Egyptians use wood and copper (there was no bronze yet) to build pyramids? And see above about the main issue of machine tool building.

A lathe for processing wood can be made of metal (pos. 1 in the figure), metal-wood, pos. 2, from scrap materials with minimal use of metal, pos. 3 and even... without a frame, pos. 4. So, on any of them, a sufficiently experienced and careful craftsman can regularly work for a long time with maximum precision for wood. Wood is not only a noble, but also a grateful material.

What tree?

Yes, but what kind of wood should I take? The best is oak without defects, seasoned, having undergone complete natural shrinkage and shrinkage. Lathes made of high-quality oak 100 or more years ago are still in operation. As for homemade work, the bed and headstocks of an oak (literally) machine are made very simply, see below.

If there is no oak lumber of suitable quality, then you can get by with ordinary construction pine, but the frame will have to be made according to a frame-beam power scheme. In Anglo-Saxon countries, where oaks have long been registered individually, such home lathes are very common. Drawings of an “English” wood lathe with a frame made of ordinary timber are shown in Fig; dimensions in inches. This is actually an ancient foot-operated machine with a crank, adapted for an electric drive. To return it to a non-volatile form, it is enough to extend the middle stand of the frame to the bottom, place it on a paw and mount the pedal with a connecting rod, crank and flywheel, see above.

Drive

Working with a muscle motor is, of course, not an acquired taste: now electricity is available almost everywhere. In extreme cases, you can also get power from a car battery through a voltage converter. If you come across something like this somewhere in other articles on this topic: pull a 3-phase cable towards you, do protective grounding, buy a 3-5 kW motor, don’t believe the elephant that he’s a buffalo. To round a piece of wood of average “clumsiness” to a diameter of 300 mm, a machine drive power of 1-1.5 kW is sufficient; for turning 200 mm logs into a figured support post – 350 W.

Spindle speed is much more important. Its rotation frequency should not exceed 600-700 rpm, otherwise the likelihood of “biting” the cutter and causing a traumatic situation increases sharply. It is best to limit yourself to speeds set in the range (60-70) - (300-400) 1/min. Then the following are possible. drive options:

• Asynchronous motor with double insulation and capacitor start + mechanical transmission.
• The engine is the same type, 2-4 speed.
• Drive by electric drill.

Just a motor

It’s not easy, because it is impossible to regulate the rotation speed of an asynchronous electric motor by changing the supply voltage: the rotor slip increases like an avalanche and, accordingly. torque drops. Making a powerful frequency converter is difficult and expensive. All that remains is a 2-3 speed manual transmission. Belt or chain - they dampen jerks due to inhomogeneities of the workpiece, and gear, on the contrary, strengthens them. Plus – heavy rotor, heavy pulleys, elastic belt. The inertia of the torsional drive is such that it is possible to sharpen completely knotty blocks of shape on a cut that has nothing in common with a circle. The downside is that you need to order or look for turned pulleys.

Motor from washing machine

The rotation speed of an asynchronous electric motor can be changed stepwise by switching the windings. Motors of this type are installed in some models of washing machines (only these are installed in washing machines with direct drum drive) and in floor fans with airflow switching. The rotation speeds in both cases are ideal for wood turning. Motor power from fan approx. 40-70 W, which is enough for a mini-machine (see below). The motor power from the washing machine is 300-400 W – quite enough.

Drawings of a wood lathe with a motor from a washing machine are shown in the figure:

The motor from a washing machine with direct drum drive as a drive for a lathe for wood processing has a great advantage: its bearing units are designed for a large unbalanced load, so the most viscous and twisted wood can be turned. But with knots the situation is worse: the flywheel is only a motor rotor, and the cutter will twitch on them.

Note: how to make a wood lathe with a washing machine motor, see video:

Video: lathe with a washing machine engine

From a drill

For both machines, from the point of view of a conventional home handyman there is a big drawback: on the headstock you need to either install a gripper only for wood, or order an adapter for the motor shaft with a Morse taper for a clamping jaw chuck. Finding the sizes of standard Morse cones on the Internet is not difficult; For the dimensions of the cone for a regular drill chuck No. 1, see Fig. right. But – you need to sharpen the cone with an accuracy no worse than +/–0.025 mm. That is, you need a metal lathe with increased accuracy of 0.02 mm. There may simply not be a sufficiently qualified master who owns such equipment within reach.

If the machine drive is an electric drill, the problems of precision machining disappear: the chuck can be removed with a homemade puller, and a standard commercial holder for a wooden workpiece can be placed on the cone. Or simply clamp the same one in a chuck, but cheaper with a cylindrical shank. Or even make a workpiece holder yourself (see below).

The design of such an important unit as the headstock in a drill lathe is also extremely simplified: it turns into a simple clamp. Two options for drawings of a clamp for a drill to a lathe are shown in Fig:

Headstocks - clamps for a wood lathe from a drill

On the left is metal; on the right - made of solid, fine-grained wood. Wooden is better: it dampens vibrations well and does not damage the collar of the drill. Its production has a certain peculiarities:

1. Threaded rod for clamping wing 1 is needed M10-M12;
2. The blind hole for the pin is first drilled 1-1.5 m narrower so that it fits into it with a turn along the thread;
3. The upper part of the hole is drilled to its full diameter;
4. The pin is screwed in until it stops;
5. The workpiece is laid flat and a through hole is drilled in place for a locking screw 2 M4-M6;
6. Fix the pin with a locking screw;
7. The assembly is finally assembled.

An electric drill as a machine drive has only one drawback: brushed motor With thyristor regulator rpm At low rotation speeds, the torque on the shaft drops noticeably, this can be felt already during drilling. Therefore, on a machine from a drill with a power of 280-350 W you can sharpen wooden blanks diameter approx. up to 150 mm. However, the simplification of the manufacturing technology of a lathe for wood processing driven by a drill is so thorough that machines from a drill are made in the most various options, see video selection:

From scrap materials without a bed:

Video: wood lathe quickly

With a plywood frame:

Video: plywood lathe with drill motor

Regular design:

Video: universal wood lathe

Improved with expanded functionality:

Video: Improved wood lathe from a drill

bed

Metal and oak wood lathe beds have their advantages and disadvantages. But by combining wooden power (load-bearing) elements with reinforced metal fasteners, it is possible to obtain a frame that is made “on the knee” hand tools+ electric drill and will last at least 20-30 years.

The design of the combined bed of a wood lathe is shown in the figure:

The main structural material is a standard oak beam 100x100, 3 m long. The overall length of the frame is 1.2 m. The drawing is to scale, the missing dimensions can be removed and converted into mm from it. If good oak there is more, the length of the bed can be increased to 1.5-2 m. Both headstocks are of the same design and are designed for homemade rotation units, see below. The ridges at the bottom of the headstocks prevent misalignment of the centers. The entire structure can be made with hand carpentry tools and an electric drill.

Note: A mini wood lathe was made using essentially the same power circuit, see next. rice. A motor from a 2-3 speed floor fan, see above, with a 1:1 gear is suitable for it.

If it's still metal

The entire set of qualities of an oak bed is quite sufficient for wood turning. The use of metal for this purpose in mass production is dictated by economic considerations: simply the cost metal product, intended for continuous 3-shift operation, turns out to be much smaller than a wooden one. 1 cu. m of seasoned oak costs much more than a hundredweight of conventional structural steel.

Amateur craftsmen, without knowing it, often “for the sake of strength” make the beds of wood lathes from channel bars. But it turns out rough even for “wooden” precision (on the left in the figure), and it is not realistic to trim the working surfaces of channels at home. In addition, welding can cause the entire structure to act like a “propeller,” which is completely impossible to correct. Therefore, it is better to assemble a channel frame with bolts (on the right in the figure).

Much more reliable in this regard is a frame made of paired pipes (on the left in the next figure): when welding, it moves less, the misalignment can be corrected by tightening the frame with bolts to the base, and it is possible to achieve a divergence of the centers of the manufactured in a makeshift way headstocks of 0.2 mm or less. Drawings of a welded tubular bed of a wood lathe from a drill are also shown in Fig.

Grandmas

It would seem that it is impossible to make the headstocks of a lathe, and the back one with a rotating center, without precision turning operations. No, it’s possible – using the phenomenon of an oil hydrodynamic cushion (OHB). This, by the way, is one of the ways to answer the question: how to make parts for a machine with an accuracy of 0.2 on a machine with an accuracy of 1. In mechanical engineering, HDP is rarely used, because for its formation and stabilization, the machine with the workpiece fixed in it must run at idle for 2-5 minutes. If a shift lesson consists of only 10 parts, then the daily loss of working time will be up to an hour or half an hour, which is “off scale” in mass production. But in general, HDP is not uncommon in technology. For example, warming up the internal combustion engine of your car is necessary, incl. and in order for the GDS to form between the connecting rod clamps and the crankshaft journals, otherwise the engine life is sharply reduced.

What is GDP

The principle of operation of the HDP is shown in the figure:

Any grease is suitable for it: grease, grease, cyatim, fiol. But the best thing is shahtol, a special lubricant for mining machines and mechanisms. Due to difficult working conditions, they, like the Kalashnikov assault rifle, are made with large gaps between the rubbing parts, but they are not required to have a rate of fire. Shakhtol is specially designed for relatively slow movable rotation joints and is perfectly suited for the headstocks of a wood lathe using a GDP.

Headstock

The structure of a typical headstock of a woodworking lathe is shown on the left in Fig. There are already a lot of metal lathes in it for the amateur, and the shaft journals and bearing cap seats need to be sharpened with the same precision as a Morse taper.

For a homemade headstock using the HDP, you will need, in addition to purchased threaded parts: M12-M20 studs for the shaft, nuts and washers for them, another piece of bronze (not brass!) foil 0.2-0.35 mm thick and, for the holder, a steel tube with walls of sufficient thickness (see right in the figure). The entire assembly assembly is made. way:

1. The tube on the holder is cut exactly to size according to the thickness of the headstock's wooden body, and pressed into it;
2. The body with the holder is laid flat, laid flat and the tube is drilled out along the diameter of the threaded shaft;
3. The inner corners of the cage holes are smoothed by hand scraping - a reamer - as is done when installing air conditioners;
4. A rectangle is cut out of bronze foil with a height equal to the thickness of the headstock body and a width of 3 shaft diameters (for M12 36 mm, for M16 48 mm), its corners are slightly cut at 45 degrees. 3 diameters, because the bronze liner should barely meet at the edges, and π=3.1415926...
5. From the same foil, using a ballerina compass with two needles, cut out 6-8 bronze washers;
6. The washers are pressed one by one with your palms between plywood with fine sandpaper glued to them and, turning your hands back and forth, the burrs are removed;
7. The shaft is wrapped in the same sandpaper and, squeezing it with your hand, the shaft is pulled through several times with a twist to slightly remove the sharp edges of the thread;
8. Wrap the shaft in foil and try to insert it dry into the holder. If necessary, repeat operation 7. It is necessary that the shaft in the foil wrapper fits tightly and is difficult to turn in the cage by hand;
9. Take out the shaft, remove the foil and screw one of the nuts onto it until it fits;
10. Coat the shaft threads liberally with grease;
11. The same grease is used to lubricate the inside of the cage;
12. Place a regular steel and 3-4 bronze washers on one side, generously lubricating each one with the same lubricant;
13. Wrap the shaft in foil again and insert it into the cage;
14. Put in reverse order washers on the other side, also generously lubricating;
15. Screw and tighten the other nut so tightly that the shaft can barely be turned by hand;
16. The nuts are temporarily secured with locknuts;
17. Lay the workpiece flat and drill through holes for the cotter pins;
18. The standard nuts are tightened. It is best to cut bicycle spokes, they have very high shear strength;
19. They assemble the headstock, put its pulley in place;
20. Turn the pulley by hand until it rotates tightly, but without jamming;
21. Assemble the machine drive and start it idling at minimum spindle speed (in the slowest gear) until the motor reaches full speed. If necessary, push the pulley with your hand;
22. Repeat step 21 for maximum speed spindle (in the fastest gear);
23. Place the workpiece gripper in place - the unit is ready for work.

If you don’t trust all sorts of very clever physics (although units with HDF maintain accuracy no worse than their rolling friction counterparts), then in Fig. – drawings of a bearing assembly, equally suitable for homemade circular saw and a wood lathe. In the latter case, a flat sole with side supports is not needed - the round body is simply inserted into the headstock body and secured with a screw. Instead of a saw blade, use either a faceplate or an adapter with a cone for a clamping chuck (part 6).

Tailstock

The designs of the rotating centers of lathes for metal (above in the figure on the right) and wood (at the bottom) are not fundamentally different, only the “wooden” one is designed for many times lower loads. But in work, especially at home, there is a significant difference: axial holes in turned wooden parts are drilled extremely rarely, because This greatly reduces their strength - wood, unlike metal, cracks easily. That is, by abandoning the quill for replaceable working parts, it is possible to simplify the design of the tailstock until it is suitable for manufacturing “on the knee” with a small proportion of simple custom-made turning work.

A typical tailstock design for a wood lathe is shown in Fig. below. On the right there is an insert with a rotating center in the wooden tailstock, made from a garage door hinge. The HDP is also used here, and the center shank is adjusted to the holder in the same way as the headstock shaft, but simpler and lighter: the gap between the pin and the socket of the garage hinge is approx. 0.5 mm and, as a rule, the unit turns out to be suitable for operation without adjustment and lapping.

Some difficulties are caused only by fixing the center from the reverse longitudinal stroke. It is unrealistic to cut a trapezoidal thread and make a locking block or eccentric for it at home, and a locking screw will quickly crush a regular metric thread. The output is a floating aluminum bushing. Mechanics are familiar with this method: if you need to clamp a threaded part in a vice, they wrap it in thin aluminum or place it between aluminum spacers - absolutely nothing happens to the thread.

Podruchnik

The simplest tool for a chisel is a piece of board with a wooden boss nailed/screwed to it. But for fine workmanship this is not suitable: when sharpening shaped parts, you need to rotate the shelf (stop) of the cutter without loosening the fastening of the tool rest itself and without displacing it. Therefore, the tool rest needs to be made of metal with a rotary stop, but custom turning and milling work is not required for this; for drawings see fig. right.

Holder

So we come to the last question: how to securely secure the workpiece in the headstock of a woodworking lathe? Considering that wood easily tears, crumples, and chips, and the wood that is turned into a lathe sometimes comes in simply amazing shapes.

The answer to this question is not as scary as the devil paints it. Universal holder– trident, pos. 1 in Fig. This is exactly what household woodworking machines are equipped with, for example. the mentioned UBDN-1. The shank is either smooth for a clamping chuck, or threaded for installation on the shaft. The trident holder reliably holds workpieces up to 100-120 mm in diameter, and round ones – up to 200 mm. There is only one drawback: it is very difficult to make a good trident for a wood lathe.

Screw chuck for small clean work (e.g. turning wooden glasses), pos. 2, it is generally impossible to do without special equipment, but it is successfully replaced by a clamping chuck, pos. 3. If, on the contrary, you need to process a large workpiece with an irregular configuration in the cut, use a faceplate, pos. 4.

A faceplate for wood turning can also be made independently from bakelized plywood with a thickness of 12-16 mm. In this case, the washer is made of 2 layers: the same one made of sheet steel 1-1.5 mm thick is attached to the plywood circle on the back side. The holes for the tenons in the plywood circle are drilled through, and instead of the turned tenons, you can then install the cut off points of the nails. The glass for installing the faceplate under the nut on the threaded shaft shank can also be assembled from plywood rings and a steel bottom.

Finally, based on a 3-4-layer faceplate, you can make a homemade wood-look jaw chuck, pos. 5. Are your fists definitely not going to meet? So the accuracy of the workpiece is even worse. But you can sharpen from sections valuable wood bowls, saucers, etc. products on which there will be no traces of processing.

Note: The variety of holders for wooden workpieces is not limited to those described. For example, see the video on how to make a mini lathe with a crown holder for the most minor works on wood:

Video: mini wood lathe

In conclusion

Making a machine and working on it are different things, not only in industry. Therefore, finally, see a selection of videos on how to sharpen wood on a machine and make it out of a grinder copying machine on wood for turning balusters.