Screw-cutting lathe. Do-it-yourself homemade metal lathe: manufacturing and operation Cast a transverse support for a lathe from aluminum

Lathes have been known since ancient times. Machine tools of that time, as can be seen from Fig. 20 were very primitive. The support was not yet known, so the cutter had to be held by hand while working, and the rotation of the workpiece was also conveyed manually using a rope. It is clear that working on such a machine required a lot of physical strength and could not be productive.

In 1712, for the first time in the world, Russian mechanic Andrei Konstantinovich Nartov created a lathe with a mechanically driven support.

The invention of the caliper by A.K. Nartov freed the turner’s hands from the need to hold the cutter while turning the part and marked the beginning of a new era in the development of not only lathes, but also other metal-cutting machines.

A. Nartov made his lathe with a support 70 years earlier than the Englishman Maudsley, to whom the invention of the support is incorrectly attributed in the West, and was 70 years ahead of Western Europe and America.

After Nartov, the production of lathes was especially widely developed at the Tula and other arms factories. One of these machines is shown in Fig. 21. The supports 2 of these machines were moved mechanically using gears 1 and a screw 3 with a nut.

The lathe shown in Fig. 22, manufactured in the middle of the last century, is closer in design to modern machines. He has headstock with stepped pulley 1, which allows you to change the speed of the workpieces. The support 2 is moved using lead screw 3, a nut installed in the apron, and replaceable gears 4.

Later, on lathes with step-pulley drives, they began to use feed boxes; in addition to the lead screw, they began to use drive shaft. At the beginning of the 20th century. With the invention of high-speed steel, high-speed powerful lathes appear, in which the spindle speed is changed using gears enclosed in gearbox.

Thus, modern lathes have speed boxes for changing the number of revolutions of the workpiece and a feed box for changing the feed rate.

In Fig. 23 shows the names of the main components and parts of a screw-cutting lathe.

The bed is a support for the headstock and tailstock, and also serves to move the caliper and tailstock along it.

The headstock serves to support the workpiece and transmit rotation to it.

The tailstock serves to support the other end of the workpiece; also used for installing drills, reamer, taps and other tools.

The support is designed to move the cutter fixed in the tool holder in the longitudinal, transverse and inclined directions to the machine axis.

The feed box is designed to transmit rotation to the lead screw or lead shaft, as well as to change the number of their revolutions. The lead screw is used to transmit motion from the feed box to the caliper carriage only when cutting threads, and the lead shaft is used when performing all basic turning operations.

The apron serves to convert the rotational movement of the drive shaft into longitudinal or transverse movement of the caliper.

2. Bed

All components of the lathe are mounted on a bed standing on two pedestals (legs).

The bed (Fig. 24) consists of two longitudinal walls 2 and 8, connected for greater rigidity by transverse ribs 1, and has four guides, three of which are prismatic 3

and one flat 4. At the left end of the frame 5 is attached headstock, - and on the other, on the inner pair of guides, they install tailstock. The tailstock can be moved along guides along the bed and secured in the required position. The lower plate of the support, called the carriage, moves along the two outer prismatic guides of the frame. The bed guides must be accurately machined along the working planes. In addition, the guides must be strictly straight and mutually parallel, since the accuracy of the processing of parts depends on this.

3. Headstock

The headstock is the part of the lathe that serves to support the workpiece and cause it to rotate. In the headstock housing, a spindle rotates in sliding or rolling bearings, which transmits the rotation of the workpiece using a cam or drive chuck screwed onto the right end of the threaded spindle.

On the outer wall of the headstock housing there are gearbox handles (see Fig. 23), which are used to switch the spindle speed. How to turn these handles to obtain the required number of spindle revolutions per minute is indicated on a metal plate attached to the outer wall of the headstock.

To protect the gears of the gearbox from premature wear, switching the handles should be done only after turning off the spindle, when its speed is low.

4. Spindle

Spindle design. The spindle (Fig. 25, a) is the most critical part of the lathe. It is a steel hollow shaft 1, into the conical hole of which the front center 5 is inserted, as well as various mandrels, devices, etc. The through hole 7 in the spindle is used to pass the bar when performing bar work, as well as to knock out the front center.

At the front end of the spindle there is a precise thread 4 cut onto which a cartridge or faceplate can be screwed, and behind the thread there is a neck 6 with a collar 3 for centering the cartridge; The 1A62 machine, in addition, has a groove 2 for chuck guards, which prevents it from spontaneously collapsing during rapid braking of the spindle.

The spindle rotates in the headstock bearings and transmits the rotation of the workpiece. In lathes, spindles usually rotate in plain bearings, but high-speed spindles rotate in rolling bearings (ball and roller), which have higher rigidity than plain bearings.

One of the main conditions for precise processing of parts on lathes is the correct rotation of the spindle. It is necessary that the spindle, under the influence of a load, should not have any play in the bearings - neither in the axial nor in the radial directions - and at the same time rotate evenly and easily. The presence of slack between the spindle and bearings causes spindle runout, and this in turn leads to inaccurate processing, vibration of the cutter and the workpiece. Spindle stability is ensured by the use of a new type of massive adjustable rolling bearings.

Front spindle bearing. In Fig. 25, c shows the design of the front (right) bearing of the lathe spindle. The conical neck 8 of the spindle rotates in a double-row roller bearing 9, which receives forced lubrication from a special pump located in the gearbox. The inner conical ring 10 of the roller bearing is bored along the spindle journal.

When adjusting the bearing, loosen the locking screw 11 and turn the nut 12, due to which the ring 10 moves along the axis. In this case, due to the taper of the neck 8, the gap between it and the conical ring changes. When turning nut 12 to the right, the bearing is tightened, and when turning to the left, it is loosened. The movement of the ring 10 is carried out so that the spindle with the chuck can be turned manually. After adjustment, tighten the locking screw 11, which protects the nut 12 from unscrewing.

Rear spindle bearing. The rear spindle bearing is loaded significantly less than the front one. Its main purpose is to perceive forces acting on the spindle in the axial direction.

The rear journal of the spindle usually rotates in a tapered roller bearing 14 (Fig. 25, b). The axial force acting on the spindle from right to left is perceived by a thrust ball bearing 13 located at the rear support of the spindle. If the axial force is directed from left to right, trying to pull the spindle out of the gearbox, it is perceived by the tapered roller bearing 14. This bearing also serves as a support in the transverse direction for the rear end of the spindle. It is adjusted using nut 15 in the same way as the front bearing.

5. Tailstock

The tailstock serves to support the right end of long parts when processing them in the centers. In some cases, it is also used to install drills, reamers, taps and other tools.

Tailstock with regular center. Tailstock housing 1 (Fig. 26, a) is located on plate 9 lying on the frame guides. A quill 6 with a nut 7 fixed in it can move longitudinally in the housing hole. At the front end, the quill is equipped with a conical hole into which the center 3 and sometimes the tail part of a drill, countersink or reamer is inserted. The quill 6 is moved by means of a handwheel 8 that rotates a screw 5; When the screw rotates, it moves nut 7, and with it the quill. Handle 4 serves to firmly secure the quill in the headstock body. By means of screws 10, it is possible to shift the body 1 relative to the plate 9 in the transverse direction and thereby shift the axis of the tailstock quill relative to the axis of the spindle. This is sometimes resorted to when turning flat cones.

To turn the centers of parts of different lengths, plate 9 is moved along with the tailstock body along the bed and secured in the desired position. The headstock is secured to the frame using clamping bolts or using an eccentric clamp and bracket 11. Using handle 2, turn the eccentric roller and release or tighten bracket 11. Having released the bracket, move the tailstock and, having installed it in the desired position, tighten the bracket again.

To remove the rear center from the conical socket of the quill, turn the handwheel 8 so as to pull the quill into the tailstock body as far as it will go. In the extreme position, the end of screw 5 pushes out center 3.

Tailstock with built-in rotating center. In lathes for high-speed cutting, tailstocks with a built-in rotating center are used. In Fig. 26, b shows one of the designs of such a tailstock.

In the front part of the quill 5 there is a hole into which the bearing 3 with tapered rollers, the front thrust ball bearing 4 and the rear ball bearing 6 for the sleeve 2 are pressed. This sleeve has a conical hole into which the center 1 is inserted. The axial force is absorbed by the thrust ball bearing 6. If you connect bushing 2 with quill 5 using a stopper, the bushing will not rotate. In this case, you can install a drill or other centering tool (countersink, reamer) in the tailstock.

6. Feed mechanism

The mechanism for transmitting movement from the spindle to the support (Fig. 27) consists of: bit I, designed to change the direction of feed; guitars II with replaceable gears, which makes it possible, together with the feed box, to receive various feeds (large and small); feed boxes III; lead screw 1; drive shaft 2; apron IV, in which mechanisms are located that convert the rotational movement of the lead shaft and lead screw into the translational movement of the cutter.

Not all machines have all the listed mechanisms. For example, in machines designed exclusively for cutting precise threads, there is no feed box; the feeds here are changed by changing the gears on the guitar. On the other hand, on some machines the feed unit has two reversing mechanisms: one serves only to change the direction of rotation of the lead screw (which is required, for example, to switch from cutting right-hand threads to cutting left-hand threads), and the other changes the direction of rotation of the lead shaft, changing thus the direction of longitudinal or transverse feed.

Snaffle bit. In Fig. 28 shows a snaffle that was widely used in older types of screw-cutting lathes. A gear 1 is attached to the end of the spindle, with which, using lever A, either wheel 4 or wheel 2 can be engaged. Gear 2 is constantly engaged with wheel 4 and wheel 3. If, by turning lever A down, wheel 1 is engaged with wheel 4, then the rotation of wheel 3 will be transmitted through two intermediate wheels 4 and 2 (Fig. 28, c). By turning lever A upward (Fig. 28, a), we engage wheel 1 directly with wheel 2. In the latter case, wheel 5 will receive rotation only through one intermediate wheel, therefore, it will rotate in a different direction than in the first case. If lever A is fixed in the middle position, as shown in Fig. 28, 6, then gears 4 and 2 do not engage with wheel 1 and the feed mechanism will be turned off.

In Fig. 29, b. another design of a reversing mechanism made of cylindrical wheels is shown. On drive shaft I a block of two wheels 1 and 3 sits freely to communicate forward motion to driven shaft II and wheel 5 for reverse motion. Wheels 1, 3 and 5 can be rigidly connected to shaft I using a plate-type friction clutch M.

On the driven shaft II there is a movable block consisting of wheels 2 and 4 on the left, and wheel 6, rigidly fixed to the key, on the right.

Feed box. Most modern screw-cutting lathes have feed boxes; they serve to quickly switch the rotation speed of the lead screw and the lead shaft, i.e., to change the feed. Replaceable wheels on these machines are used only when the required feed cannot be achieved by switching the feed box handles.

There are many different feedbox systems. A very common type is the feed box, which uses ring gear mechanism(Fig. 30).

The first roller 7 of the feed box receives rotation from the replacement wheels of the guitar. This roller has a long keyway 6, in which the key of the gear 3 located in the lever 2 slides. Lever 2 carries an axis 5, on which the ring wheel 4 rotates freely, constantly engaged with wheel 3. By means of lever 2, wheel 3 together with wheel 4 can be moved along roller 7; By turning lever 2, you can engage the rim wheel 4 with any of the ten wheels of the toothed cone 8, mounted on the roller 9.

Lever 2 can have ten positions according to the number of wheels of the gear cone 8. In each of these positions, the lever is held by a pin 1 entering one of the holes in the front wall 15 of the feed box.

When the lever 2 is moved, due to the adhesion of the wheel 4 with the various wheels of the gear cone 8, the rotation speed of the roller 9 changes. At the right end of this roller, on a sliding key, there is a wheel 10, which has a number of protrusions on the right end. In the left position, wheel 10 is engaged with wheel 14, mounted on the running shaft 13. If the wheel 10 is shifted to the right, along the shaft 9, it will disengage with the wheel 14 and the end protrusions will engage with the cam clutch 11, which is rigidly seated on the lead screw 12. In this case, shaft 9 will be directly connected to the lead screw 12. When the lead screw is turned on, the lead shaft 13 remains stationary; on the contrary, when the drive shaft is turned on, the lead screw remains motionless.

On the wall of the feed box there is usually a sign indicating which feeds or which thread pitches are obtained for each of the ten positions of lever 2 with a certain selection of guitar wheels.

7. Caliper

The lathe support (Fig. 31) is designed to move the tool holder with the cutter in the longitudinal, transverse and inclined directions to the machine axis. The cutter can be given movement along and across the bed both mechanically and manually.

The lower plate 1 of the caliper, called carriage or longitudinal slides, moves along the bed guides mechanically or manually, and the cutter moves in the longitudinal direction. On the upper surface of the carriage 1 there are transverse guides 12 in the shape of a dovetail, located perpendicular to the frame guides. The lower transverse part 3 moves on the guides 12 - cross slide supports, through which the cutter receives movement perpendicular to the axis of the spindle.

On the upper surface of the cross slide 3 there is turning part 4 calipers. By unscrewing the nuts 10, you can rotate this part of the caliper at the desired angle relative to the frame guides, after which the nuts 10 need to be tightened.

On the upper surface of the turning part there are guides 5 in the shape of a dovetail, along which, when the handle 13 rotates, the upper part 11 moves - upper caliper slide.

Caliper adjustment. After a certain period of operation of the machine, when a gap appears on the side surfaces of the dovetail, the accuracy of the machine operation decreases. To reduce this gap to a normal value, it is necessary to tighten the wedge strip available for this purpose (not shown in Fig. 31).

The excess gap that occurs after a certain period of work between the nut and the transverse lead screw should also be reduced to a normal value.

As can be seen from Fig. 32, the nut covering the transverse screw 1 consists of two halves 2 and 7. To reduce the gap between the nut and the screw to a normal value, the following must be done. Lightly unscrew screws 3 and 6, with which both halves of the nut are screwed to the bottom of the caliper, then use screw 5 to move the one-sided wedge 4 upward, while both halves of the nut move apart and the gap between the transverse screw and the nut decreases. After adjusting the gap, you need to tighten the screws again. 3 and 6, securing both halves of the nut.

Tool holders. A tool holder is installed on the upper part of the caliper to secure the cutters. Tool holders come in various designs.

On light machines, a single tool holder is used (Fig. 33, a). It is a cylindrical body 1, into the slot of which a cutter is inserted and secured with a bolt 2. The cutter rests on a lining 3, the lower spherical surface of which is in contact with the same surface of the ring 4. This device allows you to tilt the lining with the cutter and set its cutting edge to the height of the centers . The lower part 5 of the tool holder, which has a T-shape, is inserted into the groove in the upper part of the caliper. Fastening the cutter in a tool holder of this type is quick, but not strong enough, so this tool holder is used mainly for small jobs.

The cutter is fixed more firmly in the tool holder shown in Fig. 33, b. The tool holder 5, equipped with a T-shaped block 1, is fixed on the upper part of the support with a nut 4. To adjust the position of the cutting edge of the tool in height, the tool holder has a lining 2, the lower spherical surface of which rests on the same surface of the tool holder block. The cutter is secured with two bolts 3. A tool holder of this type is used on both small and large machines.

On large lathes, single tool holders are used (Fig. 33, b). In this case, the cutter is installed on plane 7 of the upper part of the caliper and secured with strap 2, tightening nut 4. To protect bolt 3 from bending, strap 2 is supported by a screw resting on shoe 6. When unscrewing nut 4, spring 1 lifts strap 2.

Most often, tetrahedral rotary cutting heads are used on medium-sized screw-cutting lathes (see Fig. 31).

The cutting head (tool holder) 6 is installed on the upper part of the support 11; Four cutters can be secured in the tool holder with screws 8 at the same time. You can work with any of the installed cutters. To do this, you need to turn the head and put the required cutter in the working position. Before turning the head, it is necessary to unfasten it by turning handle 9, connected to the nut sitting on screw 7. After each turn, the head must be clamped again using the same handle 9.

8. Apron

An apron 17 is attached to the bottom surface of carriage 1 (see Fig. 31) - this is the name of the part of the machine that contains mechanisms for longitudinal and transverse movements of the cutter (feed) and feed control mechanisms. These movements can be done manually or mechanically.

The transverse feed of the cutter is carried out by moving the lower part 3 of the caliper. To do this, handle 14 rotates the screw, the nut of which is fastened to the lower part of the caliper.

Handwheel 16 is used to manually communicate longitudinal feed to the caliper along the bed guides. For more precise mechanical movement of the caliper, a lead screw is used (Fig. 34). Screw 1 is driven by the feed box. A split nut 2 and 8 moves along it, installed in the caliper apron and called uterine. When cutting a thread with a cutter, both halves of the nut 2 and 8 are brought together using handle 5; they capture the thread of screw 1 so that when it rotates, the apron, and with it the caliper, receive longitudinal movement.

The mechanism for sliding and spreading the halves of the split nut is designed as follows. On the handle shaft 5 (Fig. 34) there is a disk 4 with two spiral slots 6, into which the fingers 7 of the lower 8 and upper 2 halves of the nut fit. When the disk is turned, 4 slots force the fingers, and therefore the halves of the nut, to move closer together or diverge. The nut halves slide along dovetail-shaped guides 3 of the apron.

In all turning operations, except for cutting threads with a cutter, longitudinal feed is carried out using a gear rack rigidly attached to the frame and a gear rolling along it installed in the apron (see Fig. 36 a). This wheel is rotated either manually or by the drive shaft.

On a lathe, you cannot turn on the longitudinal feed mechanism from the running shaft at the same time as closing the nut on the lead screw: this leads to inevitable breakdown of the apron mechanism or feed box.

To prevent such misoperations, the machine has a special mechanism called a locking mechanism.

Control questions 1. Name the main components and parts of a lathe.
2. How is the lathe bed constructed and what is its purpose?
3. What is the purpose of the headstock of a lathe?
4. What main parts and mechanisms does the headstock consist of?
5. What is the machine’s gearbox used for?
6 How does the spindle work and what is its purpose?
7. Tell us about the structure of spindle bearings (Fig. 25).
8. Tell us about the structure and purpose of the tailstock on a lathe.
9. Through what mechanisms is motion transmitted from the spindle to the machine support?
10. How does the bit work?
11. What is the feed box used for?
12. What are the main parts of the caliper?
13. What mechanisms are contained in the machine apron?
14. How is motion transmitted from the drive shaft to the machine support?

Lathe support

Lathe support repair

Equipping metal-cutting machines with supports became one of the greatest achievements of the engineering industry of the 19th century. The support is the moving part of the unit that holds the metalworking tool. During the processing of the workpiece, the support moves along the guides of the lathe, moving the cutter automatically or manually. Despite its apparent simplicity, this mechanism played an important role in reducing the cost of machine tools, as well as in their further improvement.

The main components of the support are the carriage, longitudinal slides moving along the guides of the carriage (lower slide), the upper slide, the tool holder, the rotary plate, the drive that sets the mechanism in motion. Calipers differ in the principle of location on the machine, in the direction and characteristics of movement (transverse, longitudinal, swinging) and in the type of design of the cutting head (cutting or revolving).

The condition of the caliper guides determines the processing accuracy of the product. During the operation of the machine, along with other machine components, the working surfaces and caliper components invariably wear out, as a result of which the machine loses its functionality. Repairing a lathe support can be part of the operations performed during a major overhaul of equipment, or it can be an independent measure aimed at eliminating mechanism malfunctions (see " ").

One of the most labor-intensive procedures is the restoration of carriage guides. The purpose of the work is to restore parallelism and perpendicularity of the surfaces of the guides in relation to the corresponding planes, restoring the alignment of all aligned holes. At the same time, it is important to maintain full engagement of the apron gears with the mechanical feed equipment.

Repair of a lathe support, associated with the restoration of guides, is a responsible and complex undertaking that requires the use of special high-precision equipment. As a rule, our design bureau receives heavy and medium-class lathes that require not only restoration of the caliper, but also repair work combined with other components and mechanisms of the unit. In the vast majority of cases, we are talking about major repairs.

The support is an important part of the lathe, in fact, it performs the function of the worker’s hand, holding the cutter and moving it along the workpiece. Proper maintenance of the mechanical holder will extend its service life and avoid serious repair problems.

Caring for the caliper involves periodically adjusting the gaps in the guides, eliminating play, timely cleaning or replacing the oil seal packing, regular lubrication of the slides and protecting them from mechanical damage.

In metal work, a lathe is used to produce cylindrical (conical) shaped parts. There are many models of this production device, and all of them have almost the same layout of similar components and parts. One of these is the machine support.

To better understand the functions performed by a lathe support, you can consider its operation using the example of the common 16k20 model. After reading this information, perhaps some home craftsmen will have the idea to create a homemade lathe for metal work with their own hands.

1 What is a machine support?

This is a rather complex knot, despite its apparent simplicity. How correctly it is manufactured, installed, adjusted - the quality of the future part depends, and the amount of time spent on its production.

1.1 Operating principle

The support placed on the 16k20 machine can move in the following directions:

transverse - perpendicular to the axis of the rotating workpiece for deepening into it;
longitudinal - the cutting tool moves along the surface of the workpiece to remove an excess layer of material or grind a thread;
inclined - to expand access to the surface of the workpiece at the desired angle.

1.2 Caliper design

The support for the 16k20 machine is located on the lower slide, which moves along guides fixed to the frame, and thus longitudinal movement occurs. The movement is determined by the rotation of the screw, which converts the rotational force into translational movement.

On the lower slide, the caliper also moves transversely, but along separate guides (transverse slide) located perpendicular to the axis of rotation of the part.

A rotating plate is attached to the transverse slide with a special nut, on which there are guides for moving the upper slide. You can set the movement of the upper slide using a turning screw.

The rotation of the upper slide in the horizontal plane occurs simultaneously with the plate. Thus, the cutting tool is installed at a given angle to the rotating part.

The machine is equipped with a cutting head (tool holder), which is fixed to the upper slide with special bolts and a separate handle. The caliper moves along the lead screw, which is located under the drive shaft. This feeding is done manually.

1.3 Caliper adjustments

In the process of working on a 16k20 machine, natural wear, loosening, and weakening of the caliper fastenings occur. This is a natural process and its consequences must be constantly monitored through regular adjustments and adjustments.

The following adjustments are made on the support of the 16k20 machine:

gaps;
backlash;
oil seals.

1.4 Adjusting clearances

During the transverse and longitudinal movement of the machine support 16k20 on the slide, wear occurs on the screw and its working surface due to constant friction.

The presence of such free space leads to uneven movement of the caliper, jamming, and oscillation when lateral loads arise. Excessive clearance is removed using wedges, with which the carriage is pressed against the guides.

1.5 Backlash adjustment

Backlash appears in the screw drive. You can get rid of it without disassembling it using the securing screw located on this caliper movement device.

1.6 Adjusting the seals

When working on metal for a long time on a 16k20 machine, the oil seals, which are located at the ends of the carriage protrusion, wear out and become clogged. This is visually determined when dirty streaks appear during the longitudinal movement of the caliper.

In order to eliminate this phenomenon without disassembling the unit, it is necessary to wash the felt padding and soak it in machine oil. If worn oil seals are completely unusable, they should be replaced with new ones.

1.7 Caliper repair

This lathe device wears out over time due to constant significant loads in metal work.

The presence of significant wear is easily determined by the condition of the surface of the guide slides. Small depressions may appear on them, which will prevent the caliper from moving freely in a given direction.

With timely regular maintenance, such repairs may not be necessary, but if such a defect occurs repairs should be done and in case of severe wear - replacement.

The 16K20 caliper quite often requires carriage repair, which consists of restoring the lower guides that interact with the frame guides. Particular attention is required to maintain stable perpendicularity of the carriage location.

When repairing a caliper, it is necessary to check both planes using a building level.

2

A turning device used to perform metal work can be very simple. You can assemble a homemade machine with your own hands practically from improvised materials, which are taken from mechanisms that have become unusable.

You should start with a metal frame welded from a channel, which will be the bed. The front fixed headstock is fixed to it on the left edge, and a support is installed on the right. A homemade machine made with your own hands requires a ready-made spindle with a chuck or faceplate.

The spindle receives torque from the electric motor through a V-belt drive.

When working with a machine on metal, it is impossible to hold the cutter with your own hands (unlike working with wood), so you will need a support that will move longitudinally. A tool holder is installed on it with the possibility of alternating it transversely to the direction of movement of the support itself.

The movement of the caliper and tool holder is set by a specified amount using a screw with a flywheel, on which there is a ring with metric divisions. The flywheel is driven manually.

2.2 Materials and assembly

In order to assemble a turning device with your own hands you will need:

hydraulic cylinder;
shock absorber shaft;
corner, channel, metal beam;
electric motor;
two pulleys;
Belting.

A homemade lathe is assembled with your own hands in this way:

A frame structure is assembled from two channels and two metal beams. When working in the future with parts having a length of more than 50 mm, materials with a thickness of at least 3 mm for the angle and 30 mm for the rods should be used.
The longitudinal shafts are fixed on two channels with guides with petals, each of which is bolted or welded.
To make the headstock, a hydraulic cylinder is used, the wall thickness of which must be at least 6 mm. Two bearings 203 are pressed into it.
The shaft is laid through bearings with an internal diameter of 17 mm.
Hydraulic the cylinder is filled with lubricating fluid.
A nut with a large diameter is installed under the pulley to prevent the bearings from being squeezed out.
The finished pulley is taken from a used washing machine.
The caliper is made of a plate with cylindrical guides welded to it.
The cartridge can be made from a piece of pipe of a suitable diameter, with nuts welded on it and holes made for 4 bolts.
The drive can be an electric motor of the same washing machine (power 180 W), connected to the front headstock by a belt drive.

One of the most important achievements of mechanical engineering at the beginning of the 19th century was the spread of metal-cutting machines with calipers - mechanical holders for the cutter.

The cross support device is shown in the figure below. Along the guides of the longitudinal support 1, a lead screw 12 equipped with a handle 10 moves the slide of the transverse support. The lead screw 12 is fixed at one end in the longitudinal support 1, and the other is connected to a nut (consisting of two parts 15 and 13 and a wedge 14), which is attached to the transverse slide 9. By tightening the screw 16, the nuts 15 and 13 are moved apart (with a wedge 14) , whereby. the gap between the lead screw 12 and the nut 15 is selected. The amount of movement of the transverse slide is determined by the dial 11. A rotary plate 8 is attached to the transverse slide (with nuts 7), together with which the upper slide 6 and the tool holder 5 rotate. On some machines, a transverse slide 9 is installed a rear tool holder 2 for grooving, cutting and other work that can be performed by moving the transverse support, as well as a bracket 3 with a shield 4 that protects the worker from chips and cutting fluid.

Lathes are widely used in modern industry, for example, models such as the TV-320 screw-cutting lathe, as they allow you to perform many operations on processing cylindrical parts. Their design largely depends on the models, but there are always similar elements, since the main parts are the same for all, even if they have their own characteristics. The lathe support is one of the most important parts of the machine as it is responsible for mounting the cutter. It was its appearance that made a revolutionary step in machine tool building. This element is intended to move the cutting tool, which is located in the tool holder, when processing the workpiece in several planes.

Movement is carried out in three main directions relative to the machine axis:

Transverse;
Longitudinal;
Oblique.

Movements in given directions are carried out both manually and mechanically.

photo: lathe support device

The lathe support has the following components:

Lower slide (or longitudinal support);
Lead screw;
Cross slide (or cross slide);
Rotary plate;
Guides;
Cutting head (tool holder);
Screw;
Fastening bolts;
Fastening handle;
Locking nut;
Upper slide;
Guides;
Handle for moving the rotary plate;
Handle for turning on automatic feeds;
A handle that provides control of movement along the bed;

The support of a lathe has a very complex control system, since it includes many parts. Each of the elements performs its own function, ensuring the overall performance of the mechanism. For example, the support of a screw-cutting lathe has a lower slide No. 1, which can move along the bed guides during operation to get to the workpiece. Movement is regulated by handle No. 15. Thanks to movement on the slide, longitudinal movement along the workpiece is ensured.

The transverse support of the T3 lathe also moves on the same slide, which carries out transverse movements along its guides No. 12. Thus, all this covers the movement area, which lies perpendicular to the axis of rotation of the workpiece.

On the cross slide there is a rotating plate No. 4, which is attached to it with a special nut No. 10. Guides No. 5 are installed on the rotating plate, along which the upper slide No. 11 runs. The upper slide is controlled using the rotary handle No. 13. The upper slide rotates in a horizontal plane simultaneously with the plate. It is this unit that ensures the movement of the cutter, which is carried out at an angle to the axis of rotation of the part.

The cutting head, or as it is also called - the tool holder, No. 6 is fixed on the upper slide using special bolts No. 8 and handle No. 9. The movement from the caliper drive is transmitted through lead screw No. 2 to the drive shaft, which is located under this same screw. This can be done either automatically or manually, depending on the model.

Transverse movement is carried out perpendicular to the axis of rotation of the workpiece and is used in cases where it is necessary to machine something deep into the surface of the workpiece;
Longitudinal movement is carried out along the workpiece and is used in cases where it is necessary to remove the top layer or grind a thread on the workpiece;
Inclined movement is carried out along an inclined plane and significantly expands the processing capabilities of this equipment.

The support of a lathe wears out during its operation and requires adjustment of individual parts to continue working correctly:

Adjusting the gaps. As the slide guides wear, a gap appears that should not exist. Its appearance can cause interference in the uniform movement of the sled, jamming in one place and lack of swaying when lateral forces are applied. To correct this situation, it is necessary to move the guides to the proper position and eliminate the excess gap. This is done using wedges, and the carriage is pressed against the guides.
Backlash adjustment. If play appears in the screw drive, it can be easily eliminated by adjusting the fastening nut located on the device.
Adjusting the seals. During prolonged work at the ends of the carriage protrusion, the seals become clogged and worn out, which can be easily seen by the appearance of dirty streaks that remain when the frame moves. In this case, to adjust the device, you should wash the felt padding and then soak it in oil. If it is completely worn out, it is easier to replace it with a new one.

The support of the 1K62 lathe wears out over time and may break. Most wear is noticeable along the guides of the device. Over time, the surface of the guide slide can form small depressions that interfere with normal movement. To prevent this, it is necessary to ensure timely care and lubrication, but if this does happen, then the surface of the guides must be leveled or replaced if repair cannot be achieved.

The support of the 16K20 machine also often suffers from carriage breakdowns. The repair process begins with the restoration of its lower guides, which are connected to the frame guides. Then you should set about restoring the perpendicularity of the carriage plane. When a machine support is being repaired, the relative position in both planes should be checked, which is done using a level. Also, do not forget about restoring the perpendicularity of the corresponding parts, which must fit under the apron and the gearbox located nearby.

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Lathe support. Installation and repair of a lathe support. Caliper drawings

General view of the caliper assembly with apron

Screw-cutting lathe support. View enlarged

The support of a universal lathe is designed to move a cutter fixed in a tool holder along the spindle axis, across the spindle axis and at an angle to the spindle axis.

The machine support has a cross design and consists of three main moving units - the support carriage, the cross slide of the support, and the cutting slide. In the technical literature, these units are called differently, for example, the caliper carriage may be called lower slide, longitudinal slide, longitudinal carriage. In our description we will adhere to the terminology from the Operating Manual for the 1k62 machine.

The caliper consists of the following main parts (Fig. 13):

Carriage for longitudinal movement of the caliper along the guides (longitudinal slide, lower slide)
Machine bed
Cross slide (cross carriage)
Cutter slide (top slide, rotary slide)
Cross carriage feed screw
Backlash-free detachable nut
Cross carriage manual feed handle
Gear for mechanical feed of cross carriage
Rotary plate
Four-position tool holder

In the circular guides of the transverse carriage 3 there is a rotary plate 9, in the guides of which the cutting slide 4 with a four-position tool holder 10 moves. This design allows you to install and bolt the rotary plate with the cutting slide at any angle to the spindle axis. When turning the handle 11 counterclockwise, the tool holder 10 is raised by the spring 12 - one of its lower holes comes off the latch. After fixing the tool holder in the new position, it is clamped by turning handle 11 in the opposite direction.

The apron mechanism is located in a housing screwed to the caliper carriage (Fig. 14). Worm wheel 3 rotates from the running shaft through a series of gears. Rotation from shaft I is transmitted by the gears of shafts II and III. These shafts are equipped with couplings 2, 11, 4 and 10 with end teeth, which activate the movement of the caliper in one of four directions. The longitudinal movement of the caliper is carried out by rack and pinion wheel 1, and the transverse movement is carried out by a screw (not shown in Fig. 14), rotating from a gear wheel 5. Handle 8 serves to control the nut 7 of the lead screw 6. The shaft with cams 9 locks the lead screw and the lead shaft, so that it is impossible to turn on the caliper feed from them at the same time.

Photo of the carriage and cross slide of the caliper

The support carriage (lower slide, longitudinal slide) moves along the frame guides along the spindle axis. The carriage is driven both manually and mechanically using a feed mechanism. The movement of the carriage is transmitted using an apron rigidly attached to the carriage. The carriage can be clamped to the bed with a clamping bar and screw for heavy cross-cutting work.

The apron contains mechanisms and transmissions designed to convert the rotational movement of the lead roll and lead screw into the rectilinear translational movement of the caliper carriage, longitudinal and transverse slides. The apron is rigidly attached to the caliper carriage.

In the upper part of the carriage, perpendicular to the spindle axis, there are dovetail-shaped guides for installing the transverse slide of the caliper.

Basic parameters for moving the support carriage for the 1k62 machine:

The greatest longitudinal movement of the caliper by hand using the handwheel... 640 mm, 930 mm, 1330 mm for RMC 750, 1000, 1500
The greatest longitudinal movement of the caliper along the running shaft.. 640 mm, 930 mm, 1330 mm for RMC 750, 1000, 1500
The greatest longitudinal movement of the caliper along the lead screw... 640 mm, 930 mm, 1330 mm for RMC 750, 1000, 1500
Moving the carriage one division of the dial... 1 mm

The cross slide of the caliper is mounted on the caliper carriage and moves along the dovetail-shaped carriage guides at an angle of 90° to the spindle axis. The cross slide is also driven either manually or mechanically by the feed mechanism. The cross slide moves into the lower slide guides using a lead screw and a backlash-free nut. When feeding manually, the screw rotates using handle 7, and when feeding mechanically, from a gear wheel 8.

After a certain period of operation of the machine, when a gap appears on the side surfaces of the dovetail, the accuracy of the machine operation decreases. To reduce this gap to a normal value, it is necessary to tighten the wedge strip available for this purpose.

To eliminate play in the lead screw of the cross slide when the nut covering the lead screw is worn, the latter is made of two halves, between which a wedge is installed. By pulling the wedge up with a screw, you can move both halves of the nuts apart and select a gap.

A rear tool holder can be installed on the cross slide, which is used for grooving and other work performed with cross feed.

In the upper part of the cross slide there are circular guides for installing and securing the rotary plate with the cutting slide.

Maximum movement of the slide.. 250 mm
Moving the slide one division of the dial... 0.05 mm

Photo of the machine support assembly without an apron

The cutter slide (upper slide) is mounted on the rotating part of the cross carriage and moves along the guides of the rotating part mounted in the circular guide of the cross slide. This allows the tool slide, together with the tool holder, to be installed at any angle to the machine axis when turning conical surfaces.

The cutting slide moves along the guides of the rotating part, mounted in the circular guide of the cross slide. This allows you to install the upper slide together with the tool holder with the nuts loosened at an angle to the machine spindle axis from -65° to +90° when turning conical surfaces. When turning the clamping handle counterclockwise, the cutting head is released and the latch is removed, and then rotated to the desired position. By reverse rotation of the handle, the cutting head is clamped in a new fixed position. The head has four fixed positions, but can also be fixed in any intermediate position.

On the upper surface of the turning part there are dovetail-shaped guides along which, when the handle is rotated, the incisor (upper) slide of the caliper moves.

The cutting slide carries a tetrahedral cutting head for securing the cutters and has independent manual longitudinal movement along the guides of the rotating part of the caliper.

The exact movement of the slide is determined using a dial.

Basic parameters for moving the support slide for the 1k62 machine:

Maximum angle of rotation of the cutting slide.. -65° to +90°
The price of one division of the rotation scale.. 1°
Maximum movement of the cutting slide.. 140 mm
Movement of the cutting slide by one division of the limb.. 0.05 mm
The largest cross-section of the cutter holder... 25 x 25 mm
Number of cutters in the cutting head.. 4

Restoration and repair of caliper guides

When repairing caliper guides, it is necessary to restore the guides of the carriage, cross slide, rotary slide and top slide.

Restoring the caliper carriage guides is the most complex process and requires much more time compared to repairing other caliper parts.

When repairing the carriage, it is necessary to restore:

parallelism of surfaces 1, 2, 3 and 4 of guides (Fig. 51) and their parallelism to axis 5 of the cross-feed screw
parallelism of surfaces 1 and 3 to plane 6 for fastening the apron in the transverse direction (along directions a - a, a1 - a1) and longitudinal directions (along directions b - b, b1 - b1)
perpendicularity of the transverse guides in the direction B-B to the longitudinal guides 7 and 8 (in the direction B1 - B1, mating with the frame
perpendicularity of the surface 6 of the carriage for attaching the apron to the plane for attaching the feed box to the bed
alignment of the apron holes for the lead screw, lead shaft and shift shaft with their axes in the feed box

When repairing the carriage, it is necessary to maintain normal engagement of the apron gears with the rack and with the cross-feed mechanism. The methods of recalculation and correction of these gears that exist in practice are unacceptable, since this violates the corresponding dimensional chains of machine tools.

You should not start repairs from the surfaces of the carriage mating with the frame, since in this case they seem to fix the position of the carriage resulting from uneven wear of these guides. At the same time, restoration of all other surfaces is associated with unreasonably high labor intensity of repair work.

Therefore, repairs to the carriage guides should begin with surfaces 1, 2, 3 and 4 (Fig. 51), mating with the transverse slide of the caliper.

Restoring carriage guides by installing compensation pads

Restoring the carriage guides by installing compensation pads is carried out in the following order.

The carriage is placed on the frame guides and a level is set on the surface for the cross slide. Thin wedges with a slight slope (at least 1°) are placed between the mating surfaces of the carriage and the frame and the position of the carriage is adjusted until the level bubble is set to the zero position. Then, with a pencil, mark the boundaries of the protruding parts of the wedges and, having removed them, determine the amount of skew of the carriage in the marked places. This value is taken into account when planing the longitudinal guides of the carriage.
The carriage with the device (see Fig. 35) is installed on the machine table. A control roller is placed in the hole for the screw. Using the upper and side generatrices of the protruding part of the roller, the installation of the carriage is verified to be parallel to the movement of the table with an accuracy of 0.02 mm over a length of 300 mm and secured. The check is carried out using an indicator mounted on the machine. The deviation is determined by moving the table.
Planes 1 and 3 are ground sequentially with a conical cup wheel, grain size 36-46, hardness CM1-CM2, with a cutting speed of 36-40 m/sec and a feed of 6-8 m/min. These surfaces must be in the same plane with an accuracy of 0.02 mm. Then surfaces 2 and 4 are polished sequentially.
The surface cleanliness must correspond to V 7; non-straightness, mutual non-parallelism, as well as non-parallelism to the screw axis are allowed no more than 0.02 mm along the length of the guides. Non-parallelism is checked using a device (see Fig. 12).
Place the carriage on the planer table with planes 1 and 3 on four measuring plates (not shown in the figure). A control roller is placed in the hole for the screw. Check the installation of the carriage for parallelism to the transverse travel of the caliper with an accuracy of 0.02 mm over a length of 300 mm. The check is carried out with an indicator (fixed in the tool holder) along the upper and side generatrices of the protruding part of the control roller. On surfaces 1 and 2 (Fig. 52), a control roller 4 is placed and the distance a (from the table surface to the upper generatrix of the control roller) is measured using a stand and an indicator. Measurements are taken at both ends of the roller. The size b is also determined (from the table surface to surface 3).
Surfaces 1, 2 and 3 are planed sequentially. When planing surfaces 1 and 2, a minimum layer of metal should be removed until the distortion is eliminated.
If the wear of these surfaces is less than 1 mm, it is necessary to remove a larger layer of metal so that the thickness of the installed overlays is at least 3 mm. Thanks to this, the front part of the carriage at the place where the apron is attached will be slightly higher than the rear. A deviation of 0.05 mm is allowed over a length of 300 mm. This will increase the service life of the machine without repair, since when the caliper settles, it will first be leveled and only then will it begin to skew.

Then the control roller 4 is placed on these surfaces, the distance is again determined in the manner indicated above, and the difference with the previously measured size is determined. When planing the surface, remove a layer of metal equal to the skew measurement made (see operation 1 of this technological process), add the difference between the two distance measurements a and 0.1 mm. For example, with a skew of 1.2 mm and a difference in the measurements taken a - 0.35 mm, a layer of metal equal to 1.2 + 0.35 + 0.1 = 1.65 mm is removed from surface 3. Then measure the distance b, from which the previously established size is subtracted (see operation 4). The difference between the two indicated measurements will correspond to the size of the removed metal layer.
The profile of the planed guides is checked using a control template that corresponds to the profile of the bed guides.
The carriage is installed on the repaired bed guides and the rear clamping bar is attached to the carriage. An apron is attached to the carriage (Fig. 53). The feed box housing is installed on the frame. In the holes (for the running shaft) of the feed box and apron, control rollers with a protruding part 200-300 mm long are placed. The alignment of the control rollers and the horizontality of the transverse guides of the carriage are determined by placing measuring wedges under the guide carriages (alignment accuracy 0.1 mm) and the thickness of the installed overlays (planks).

Rice. 53. Scheme for measuring the alignment of the holes in the apron feed box

Alignment is checked using a bridge and an indicator, horizontality is checked using a level.

Select textolite grade PT of the required thickness, taking into account an allowance of 0.2-0.3 mm for scraping. Cut strips corresponding in size to the carriage guides (Fig. 54)

The dimensions of the compensation pads for restoring the guide carriages, depending on the amount of wear on the guide frames, are given in Table. 4

When installing cast iron pads, they are first planed and then ground to the desired thickness.

For details on guide trims, see pages 5-8.

The planed (without scraping) surfaces of the carriage are thoroughly degreased with acetone or aviation gasoline using light-colored cloth swabs. The surfaces of the linings are also degreased (these surfaces are first cleaned with sandpaper or sandblasted). Degreased surfaces are dried for 15-20 minutes.
Prepare epoxy glue at the rate of 0.2 g per 1 cm² of surface. Apply a thin layer of glue to each of the surfaces to be glued using a wooden or metal spatula (they must be degreased). Using surfaces coated with glue, apply pads to the mating surfaces of the carriage and lightly rub to remove air bubbles. A sheet of paper is placed on the bed guides (to prevent glue from getting on them), and a carriage is installed on it without clamping. In this case, it is necessary to ensure that the pads do not move from their places. After the glue hardens, which lasts at a temperature of 18-20 ° C for 24 hours, the carriage should be removed from the frame guides and the sheet of paper should be removed.

The gluing density is determined by light tapping. The sound should be uniform in all areas.

Lubricating grooves are made on the linings and then the surfaces of the carriage are scraped along the frame guides. At the same time, it is necessary to check the perpendicularity of the longitudinal guides to the transverse guides of the carriage using a device (see Fig. 17). Deviation (concavity) of no more than 0.02 mm over a length of 200 mm is allowed. The perpendicularity of the plane of the carriage for attaching the apron to the plane for attaching the feed box to the frame is checked using a level (Fig. 55, item 3). A deviation of no more than 0.05 mm over a length of 300 mm is allowed.

Restoring the caliper carriage guides with acrylic plastic (TSh styracryl)

Restoring the accuracy of the carriage guides with acrylic plastic using this technological process, introduced in the specialized mechanical repair shop LOMO, is carried out with minimal physical labor and a significant reduction in the labor intensity of the work.

First of all, the surfaces mating with the bed guides are repaired. A layer of metal of about 3 mm is removed from these surfaces. In this case, the accuracy of installation on the planer table is 0.3 mm along the length of the surface, and the surface cleanliness must correspond to VI. Then the carriage is installed on the fixture. In this case, plane 6 (see Fig. 35) for attaching the apron and the axis of the hole for the cross-feed screw are taken as the base.

After alignment and fastening of the carriage, a minimum layer of metal is removed from the surfaces of the transverse guides, achieving parallelism of surfaces 1 and 3 of the guides (see Fig. 51) to surface 6 in the transverse direction of no more than 0.03 mm, mutual non-parallelism of surfaces 2 and 4 - no more 0.02 mm along the length of the surfaces. The repair of these surfaces is completed by decorative scraping with adjustment of the mating surfaces of the transverse slide and wedge.

Further restoration of the accuracy of the carriage position is carried out using styracryl and is carried out in the following sequence:

Drill four holes, cut a thread and install four screws 4 and 6 (Fig. 55) with nuts. The same two screws are installed on the vertical rear surface (not visible in the figure) of carriage 5. At the same time, two holes with a diameter of 6-8 mm are drilled in the middle part of the guides;
The pre-planed surfaces of the carriage mating with the frame guides are thoroughly degreased with light-colored cloth swabs soaked in acetone. Degreasing is considered complete after the last swab is clean. Then the surfaces are dried for 15-20 minutes;
A thin, uniform insulating layer is rubbed onto the repaired frame guides with a bar of laundry soap, which protects the surfaces from adhesion to styracrylic;
The carriage is placed on the frame guides, the rear clamping bar is attached, the apron is mounted, the lead screw and lead shaft are installed, connecting them to the feed box, and the bracket supporting them is installed;
The axes of the lead screw and the lead shaft are centered in the apron with their axes in the feed box and checked with device 7. Centering is carried out with screws 4 and 6, as well as with screws placed on the rear vertical surface of the carriage.

At the same time, during centering, the following is established: the perpendicularity of the transverse guide carriages to the frame guides using fixture 1 and indicator 2; parallelism of the plane of the carriage for attaching the apron to the frame guides - level 8; perpendicularity of the plane of the carriage under the apron to the plane for the feed box on the frame - level 5.

After all positions have been adjusted and the adjusting screws are secured with nuts, remove the lead screw and lead shaft, as well as the apron. Then the surfaces of carriage 1 (Fig. 56) and the bed from the side of the apron and the rear pressure strip are sealed with plasticine; Four funnels 2 are made from plasticine along the edges of the carriage, and two funnels 3 are made around the drilled holes in the middle part of the guides.

The styracrylic solution is poured into the middle funnel of one of the guides until the level of liquid styracrylic in the outer funnels reaches the level of the middle funnel; The second guide is also filled.

The carriage is kept on the frame for 2-3 hours at a temperature of 18-20 ° C, then the screws are removed and the holes under them are sealed with screw plugs or styracrylic. After this, remove the carriage from the frame guides, clean the plate, remove the tides of plastic, cut grooves to lubricate the guides (do not scrape these surfaces). At this point, the repair of the carriage guides is completed and the assembly of the caliper begins.

When performing repairs using this method, the labor intensity of operations is reduced by 7-10 times compared to scraping and 4-5 times compared to the combined method considered and amounts to only 3 standard hours. This ensures high quality repairs.

Cross slide repair

When repairing slides, straightness 1, 2, 3 and 4 (Fig. 57) and mutual parallelism of surfaces 1 and 2 are achieved. It is very convenient to repair slides by grinding. In this case, repairs are carried out as follows.

Surfaces 2, 3 and 4 are cleaned of nicks and scratches. Surface 2 is checked for paint on the slab, and surfaces 3 and 4 are checked for paint using a calibration wedge (angle ruler)
Place the slide with surfaces 2 on the magnetic table of the surface grinding machine and grind surface 1 “as clean” (heating the part during grinding is not allowed). Surface cleanliness V 7, non-flatness is allowed up to 0.02 mm.
Place the slide with the ground surface on the magnetic table and grind surface 2, maintaining parallelism to plane 1. Non-parallelism is allowed up to 0.02 mm. The measurement is made with a micrometer, at three to four points on each side. Surface cleanliness V7.
Place the slide with plane 1 on the magnetic table. Check surface 4 for parallelism to the table movement using the indicator. Deviation from parallelism is allowed no more than 0.02 mm over the entire length of the part. Set the grinding head of the machine at an angle of 45° and grind the surface 4 with the end of the cup wheel. Surface cleanliness V7.
Verify surface 3 to ensure it is parallel to the machine’s movement and grind as indicated in point 4.
Install the slide with surfaces 2, 3 and 4 on the repaired carriage guides and check the mating surfaces for paint. Paint prints must be evenly distributed over all surfaces and cover at least 70% of their area. The 0.03 mm thick feeler gauge should not pass between the mating surfaces of the carriage and slide. If the probe passes or even “bites”, it is necessary to scrape surfaces 2, 3 and 4, checking for paint along the carriage guides.

Repair of rotary slides

Repair of the rotary slide begins with surface 1 (Fig. 58, a), which is scraped, checking for paint on the polished mating surface of the transverse slide. The number of paint prints should be at least 8-10 on an area of 25 X 25 mm.

Then the surfaces are repaired by grinding in the following order.

Install the rotary slide with a scraped surface on a special device 6 and align surfaces 3 or 4 to ensure they are parallel to the movement of the table. A deviation of no more than 0.02 mm along the length of the guides is allowed.
Surfaces 2, 5, 5, 4 are polished sequentially. Grinding is carried out with the end of a conical abrasive wheel, grain size 36-46, hardness CM1-CM2. The surface cleanliness must be at least V7. Heating the part during grinding is not allowed.

Guide surfaces 2 and 5 must be parallel to plane 1. Non-parallelism of no more than 0.02 mm along the entire length is allowed. Measurements are taken with a micrometer at three to four points on each side of the part.

Non-parallelism of surface 3 to surface 4 is allowed no more than 0.02 mm along the entire length.

The measurement is carried out in the usual way: with a micrometer and two control rollers.

Check the 55° angle formed by guides 2, 3 and 4, 5 using the template in the usual way.

Upper skid repair

If surface 1 (Fig. 58, b) wears out, it should be turned on a lathe and a thin-walled bushing should be installed with epoxy glue. Then the repairs continue in the following order.

Surface 2 is scraped, checking for paint along the mating ground surface of the cutting head. The number of paint prints must be at least 10 on an area of 25 X 25 mm
Install the upper slide with a scraped plane on fixture 6 (similar to that shown in Fig. 58, a) and align surface 5 to be parallel to the table travel (Fig. 58, b). A deviation of no more than 0.02 mm along the length of the guides is allowed.
Surfaces 3 and 6 are polished. It is allowed that these surfaces are not parallel to surface 2 by no more than 0.02 mm
Grind the surface 5
Verify surface 4 for parallelism to the table travel with an accuracy of 0.02 mm along the entire length of the surface
Grind the surface 4
Surfaces 3, 5 and 6 are checked for accuracy of alignment with the guides of the rotary slide using paint in the usual way; if necessary, they are adjusted by scraping.

Installing the Lead Screw and Lead Shaft

This operation is excluded if the carriage repair is performed according to table. 5.

The alignment of the axes of the lead screw and the lead shaft, the feed box and the apron is carried out in accordance with the following standard technological process.

Install the feed box housing and secure it to the frame with screws and pins
Install the carriage in the middle part of the frame and attach the rear clamping bar of the carriage with screws
Install the apron and connect it to the carriage with screws (the apron may not be installed fully assembled)
Control mandrels are installed in the holes of the feed box and apron for the lead screw or the lead shaft. The ends of the mandrel must protrude by 100-200 mm and have the same diameter of the protruding part with a deviation of no more than 0.01 mm (play of the mandrels in the holes is unacceptable).
Move the carriage with the apron to the feed box until the ends of the mandrels touch and measure the amount of their misalignment (in the light) using a ruler and a feeler gauge.
Restore the alignment of the holes for the lead screw and the lead shaft in the feed box and apron by installing new linings, scraping the guides or carriage linings, and reinstalling the feed box.

Permissible deviation from the alignment of the feed box and apron holes: in the vertical plane - no more than 0.15 mm (the axis of the apron hole can only be higher than the feed box hole), in the horizontal plane - no more than 0.07 mm.

Reinstallation of the box height should be done when repairing carriage guides without compensating pads. In this case, the holes in the feed box for the screws securing it to the frame are milled. When moving the box horizontally, it is necessary to mill holes in the carriage for the apron fastening screws: the latter must also be shifted and then pinned again.

Drawings of a support for a screw-cutting lathe 1k62

General view of the support of a screw-cutting lathe. View enlarged

Support device for a screw-cutting lathe. View enlarged

Lapping lathe support

Lathe support repair

Scraping a lathe carriage

Catalog directory of metal-cutting machines

Passports and manuals of metal-cutting machines

Directory of woodworking machines

Buy a catalog, directory, database: Price list of information publications

Pekelis G.D., Gelberg B.T. L., "Mechanical Engineering". 1970

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Screw-cutting lathe

One of the most important achievements of mechanical engineering at the beginning of the 19th century was the spread of metal-cutting machines with calipers - mechanical holders for the cutter. No matter how simple and, at first glance, insignificant this appendage to the machine may seem, it can be said without exaggeration that its influence on the improvement and distribution of machines was as great as the influence of the changes made by Watt in the steam engine. The introduction of the caliper immediately led to the improvement and reduction in cost of all machines, and gave impetus to new improvements and inventions. The support is designed to move during processing of a cutting tool fixed in the tool holder. It consists of a lower slide (longitudinal slide) 1, which moves along the frame guides using a handle 15 and ensures the movement of the cutter along the workpiece. On the lower slide, transverse slides (transverse slide) 3 move along guides 12, which ensure the movement of the cutter perpendicular to the axis of rotation of the workpiece (part). On the transverse slide 3 there is a rotary plate 4, which is secured with a nut 10. The upper slide 11 moves along the guides 5 of the rotary plate 4 (using the handle 13), which together with the plate 4 can be rotated in a horizontal plane relative to the transverse slide and ensure the movement of the cutter at an angle to the axis of rotation of the workpiece (part). The tool holder (cutting head) 6 with bolts 8 is attached to the upper slide using a handle 9, which moves along the screw 7. The support movement is driven from the lead screw 2, from the lead shaft located under the lead screw, or manually. Automatic feeds are turned on using handle 14.

Cross caliper

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Lathe support.

The support (see Fig. 1a) is designed to move the cutting tool fixed in the tool holder during processing. It consists of a lower slide (longitudinal slide) 1, which moves along the frame guides using a handle 15 and ensures the movement of the cutter along the workpiece. On the lower slide, transverse slides (transverse slide) 3 move along guides 12, which ensure the movement of the cutter perpendicular to the axis of rotation of the workpiece (part). On the transverse slide 3 there is a rotary plate 4, which is secured with a nut 10. The upper slide 11 moves along the guides 5 of the rotary plate 4 (using the handle 13), which together with the plate 4 can be rotated in a horizontal plane relative to the transverse slide and ensure the movement of the cutter at an angle to the axis of rotation of the workpiece (part). The tool holder (cutting head) 6 with bolts 8 is attached to the upper slide using a handle 9, which moves along the screw 7. The support movement is driven from the lead screw 2, from the lead shaft located under the lead screw, or manually. Automatic feeds are turned on using handle 14.

Rice. 1a. Lathe support 16K20

Technical jaw chuck

On lathes, two-, three- and four-jaw chucks with manual and mechanized clamping drives are used. Various shaped castings and forgings are secured in two-jaw self-centering chucks; The jaws of such chucks are usually designed to secure only one part. Three-jaw self-centering chucks hold round and hexagonal workpieces or large diameter round rods. In four-jaw self-centering chucks, square-section rods are fixed, and in chucks with individual adjustment of the jaws, parts of rectangular or asymmetrical shape are fixed. A three-jaw self-centering chuck with a manual clamp is the most common device for fastening parts on lathes. Possessing a powerful but sensitive mechanism, the chuck allows you to reliably fasten parts with high accuracy of their centering, both for high-speed processing and for more delicate work. The lathe chuck can be mounted on the spindle of a machine tool or device. The most widely used is a three-jaw self-centering chuck (figure below). Cams 1, 2 and 3 of the cartridge move simultaneously using disk 4. On one side of this disk there are grooves (shaped like an Archimedean spiral) in which the lower projections of the cams are located, and on the other there is a cut bevel gear mated to three bevel gears 5. When you turn one of the wheels 5 with a key, disk 4 (thanks to gearing) also turns and, by means of a spiral, simultaneously and evenly moves all three cams along the grooves of the cartridge body 6. Depending on the direction of rotation of the disk, the cams move closer to the center of the chuck or move away from it, clamping or releasing the part. The cams are usually made in three stages and are hardened to increase wear resistance. There are cams for securing workpieces on the internal and external surfaces; when fastening on the inner surface, the workpiece must have a hole in which the cams can be placed.