Detailed review of the TV-4 lathe: operating features, dimensions, technical characteristics

The design and manufacture of TV-4 machines is carried out at the Rostov Specialized. TV-4 has different technical characteristics than professional models, since it is needed for training and developing skills in handling steel workpieces. One of the main standards that are taken into account when designing a device is ease of setup and safety. Buying a new machine today is not difficult. However, don’t forget about used equipment. People who want to turn some metal part at home are unlikely to find a cheaper option.

Short story

This equipment has been produced by the Rostov educational equipment plant since the early 1970s. Due to the specifics of its application, this machine was called “Schoolboy”.

Industrialization required professional personnel, so the country supplied all secondary educational institutions with modern technologies by those standards.

This machine is still produced at the Rostov plant to this day, as it continues to be in demand in private workshops and for turning enthusiasts.

There is also a plant in Ukraine in Grozhno, which also produces a series of this equipment. But the Rostov plant is still considered the main manufacturer of this functional mobile design.

Purpose and scope of application of a school metal lathe

Since the equipment was originally produced as educational equipment, it is small in size. Therefore, it is not suitable for processing large parts.

The TV-4 screw-cutting lathe is designed for processing parts up to 12 cm in diameter and up to 30 cm in length. This is quite enough for those who have turning as a hobby and have a need for individual processing of parts.

The machine allows you to carry out the following types of turning work:

• trimming ends;
• cut;
• cutting metric threads;
• drilling;
• grooving and boring holes.

The school lathe is equipped with all the components of a full-fledged turning tool.

Purpose of the machine

Initially, it was planned to perform the entire range of turning operations on the school model. That is why the TV-4 design has the classic layout of all machines of this type. The following turning operations are performed on it:

• Boring and turning of steel workpieces by rotation.
• High precision end trimming.
• Drilling.
• Thread cutting (metric).

In order to increase functionality, equipment is being modernized. However, you can start this only after familiarizing yourself with the specific design and technical characteristics. Modernization should not adversely affect the performance and safety of operation of the machine.

The differences between training equipment are its layout and the location of controls, which should be such that a short teenager can operate the machine without difficulty.

Specifications

The electric motor power of the equipment in question is 0.6 kW. At the same time, the total weight of the machine is 280 kg, which allows it to be easily located in domestic conditions.

Main settings

The main parameters of TV-4 include:

• distance between centers – 35 cm;
• longest turning length – 30 cm;
• the maximum diameter of the workpiece processed above the upper part of the support is 125 mm;
• diameter processed above the bed – 20 cm.

The components in the machine are classic, with certain technical characteristics that allow you to perform all turning operations typical for this type of equipment.

Spindle

It is located in the front spindle headstock and its main function is to rotate the workpiece using a three-jaw chuck. It receives 6 digits of revolutions from the receiving pulley. Maximum – 710 rpm.

The largest diameter of the processed rod on the spindle is 15 mm. The end of the spindle is threaded – M36x4.

Caliper and feed

Designed to move the cutting tool. Has 4 carriages:

• The first one moves in the direction of the bed.
• The second one moves along the transverse guides of the first carriage, moving the cutting tool in the transverse direction.
• The third one rotates 45 degrees from the middle position in both directions.
• The fourth one carries the tool holder and moves in the longitudinal direction along the third carriage.

Cutting slide

According to the technical characteristics, the incisor slide assumes a displacement of 5 cm.

Tailstock

She is also called a stubborn grandmother. This is a structural part whose main function is to support the second end of the workpiece using the center. She fixes the future detail.

It is located on a base that moves evenly along the frame guides. The thrust headstock contains a quill that moves in the longitudinal direction. Its movement is carried out by a flywheel.

Electrical equipment

The drive is carried out from an asynchronous electric motor ~220V. Through clinometer gears and a single-stage pulley, the movement is transmitted to the running shaft and gearbox.

Electrical equipment also includes an electrical panel, transformer, and fuse links. The electrical panel and magnetic starter are located in the right cabinet, and the electric motor itself with a push-button station is in the left.

General dimensions (dimensions) and weight

The machine belongs to the light class of equipment. Its parameters in mm are 1100x470x1020. Processing accuracy class H, which allows an error of no more than 10 microns.

Thanks to its comfortable size, it is even suitable for installation in an apartment or on a balcony. That is why the machine is popular among household craftsmen.

Main components and their features

As mentioned above, the TV4 machine is made according to the classical layout. Its functional and structural components are quite standard and are found in industrial equipment for similar purposes.

1. All actuators, drives and other components are mounted on the frame - the main strength base of the structure. It is made of cast iron, using the casting method, and consists of two racks. The left cabinet houses the main drive, an asynchronous motor. An under-motor plate is provided for its fastening. The main drive is powered from a three-phase 380V network; to power the equipment from a single-phase 220V line, a converter must be installed. On the left side of the bed there is a feed box, on the right there is a tailstock assembly.
2. The spindle-type headstock unit includes a gearbox. Inside the cast iron housing there is a gear system that receives torque through a V-belt drive. On the front of the spindle there are elements of a three-jaw chuck designed for fixing the workpiece. The machine operating manual provides for pouring oil into the gearbox for proper operation of the unit.
3. The guitar is an intermediate unit for transmitting torque from the gearbox to the feed unit. It is a key element of the system that drives the caliper into longitudinal movement. The gear ratio of the guitar is not changeable, it is 1:4.
4. The feed box generates torque on the drive roller or transmits force to the screw. Its tasks include changing the rotation speed of dependent devices. The feed box is equipped with a locking mechanism: when moving from the roller to the screw, the power transmission stops. This is done for security purposes. The instructions state that the feed box should be lubricated by oil poured inside the housing.
5. A machine support is a rather complex system. Its movement is provided in different types: longitudinal along the frame, along the guides, transverse on its own slide, movement on the upper slide system. For movement in the longitudinal direction there is an automated feed from the machine’s motors, the rest of the mechanics are done manually by rotating the appropriate regulators. This principle of movement allows you to change the position of the cutter. The range of options becomes even greater when you consider that the top slide has a four-position tool post and can be rotated 45 degrees.

The last important functional element of the TV-4 machine design is the apron. The task of this unit is to implement a scheme for converting the rotation of the gearbox shafts into the translational movement of the caliper. The description of the apron's operation also includes thread cutting using it.

The electrical circuits of the machine include several significant zones. The list includes:

• electrical circuit for powering the main drive motor;
• protection system represented by fuses;
• reversible magnetic starter for the main drive;

a step-down transformer with an output voltage of 12V, connected to the electrical equipment for lighting the workplace.

The electrical circuit diagram of the machine is quite simple and, given the existing need for power from a 220V network, can be modified. In particular, it is possible to construct a different connection of the motor stator windings with the installation of starting capacitors. Good results are also achieved by using frequency control of engine speed.

General design and operating principle

The cabinet of this machine is made of thick-walled sheet steel. Additionally, stiffeners are installed. An electric motor is located at the back of the cabinet. On the front part there is an operation control unit, including a reverse button, as well as an on/off button.

The rear cabinet, which is U-shaped, also has stiffening ribs at the top and bottom. Inside this structure there is an electrical panel with all the main electrical equipment of this mechanism.

On the left side of the frame there is a spindle head, to which a gearbox is connected. The spindle rotates due to a three-jaw chuck.

From the spindle block to the gearbox, rotation is transmitted by a transmission mechanism. A special feature of the mechanism of this machine is that it is impossible to install other pairs of gears, and therefore the gear ratio is always the same.

Drawings and description of the device

The basis of the entire machine is the bed. It is box-shaped with two prismatic guides. The front guide moves the carriage, and the rear guide moves the headstock. At the front of the frame there is a lead screw and a rack.

General form

General drawing

Location of controls

The controls of a screw-cutting lathe include:

• handles for setting spindle speeds;
• handle for cutting left and right threads;
• changing the direction of gears;
• drive roller shift handle;
• handle for increasing longitudinal mechanical feed;
• device for moving the cross slide;
• flywheel for moving the longitudinal carriage.

Kinematic diagram

Headstock

This is the main and main functioning element of any screw-cutting lathe. The part externally consists of a cast iron body, which includes a spindle and gearbox. Transmits the rotation element from the electric motor to the workpiece being processed.

The front spindle journal rotates in two radial thrust bearings, while the rear spindle rotates only in a radial bearing. So that the master can adjust the axis tension, there are two nuts on the spindle.

Gearbox

This design receives movement from the gearbox itself using transmission gears. The design of this part allows you to obtain metric threads with pitches of 0.8, 1.0, 1.25 mm. You can also obtain longitudinal feed of the caliper within the same limits, per spindle revolution.

On the front of the feed box cover there is a handle with which the threads and feeds are adjusted. The design of the feed box of this model eliminates the possibility of simultaneous rotation of the lead screw and the lead roller.

To lubricate the feedbox mechanism, there is a trough in the design for pouring oil. During operation, it is important to ensure that there is always a small amount of oil in this trough for lubrication.

Apron

With the help of an apron it is possible to carry out longitudinal mechanical and manual transmission from the roller and screw. For manual transmission you need to turn the flywheel, and for mechanical transmission you need to turn the handle, which starts the dog clutch.

Caliper

This design detail is necessary for securing and moving the cutter. In this version of the equipment it is equipped with four skids.

Tailstock

This is a persistent headstock, which is located on the base and secures the second end of the part during processing. The thrust head quill has a conical hole. It includes a thrust center or any other tool currently needed to process the workpiece.

Electrical circuit diagram

Purpose of the equipment

In the context of teaching turning, the TV-4 can rightfully be called a universal machine. Most workpiece processing operations are available on it. On the machine you can:

• do drilling;
• cut internal and external metric threads, and this operation can be performed either mechanically, which the device is equipped with, or manually. The classic thread pattern is available, as well as its trapezoidal, inch, and thrust versions;
• cut threads with a wide pitch range;
• perform complex cutting of multi-start threads;
• do countersinking;
• perform end processing and trimming of workpieces.

The equipment allows you to process the outer surfaces of rod-type workpieces, for example, sharpen a shaft.

Instructions for first start-up and operation

Installation and installation of the TV-4 machine must be carried out strictly by professionals. Before the first start, be sure to read the operating instructions and safety precautions.

To install the equipment, it is necessary to equip a foundation of at least 10 cm. The best option is bars or a concrete structure.

The mechanism is not equipped with level adjustment, and therefore during installation it is important to adjust the height differences. It is best if the machine is installed on adjustable supports.

There are several nuances of work that must be taken into account:

1. In preparation for the work process, it is necessary to clean the mechanism from anti-corrosion liquid and fill the container with gearbox lubricant. It is important that the ground loop is configured.
2. Before starting work, all handles must be in their original position. Only after this is it possible to carry out the initial setup of the machine. The workpiece should be firmly fixed between the spindle and thrust head. At the next stage, you should set the desired cutter.
3. After finishing the work process, it is necessary to remove chips and metal dust that has collected on the machine after work. Then check the normal operation of all main structural parts so that in case of a breakdown it can be detected in time. Be sure to check the oil level every time before starting.

TV-4 machines are reliable. Therefore, with proper use, their service life is practically unlimited. It is only important to install it correctly from the beginning.

Machine passport

The TV-4 machine does not have increased functionality, but it works successfully with workpieces made of carbide metals. It is specially made so that even a teenager can easily handle it. Equipment specifications:

• the diameter of the through hole in the spindle is 1.6 cm;
• number of possible revolutions per minute – 120, 160, 230, 375, 500, 710;
• number of stages for forward and reverse rotation – 6;
• maximum dimensions of the mounted tool are 10x12 mm;
• the caliper has 3 longitudinal gear stages;
• The tailstock quill moves up to 6.5 cm.

When planning the work process, it is necessary to take into account that this mechanism does not have a structure for braking the spindle or locking the control handles. Due to this feature, a slow stop of the future workpiece occurs.

You can download the entire passport for free from this link - TV-4 machine passport

Characteristics and parameters

TVSh 3 first appeared in the early sixties of the 19th century on the territory of modern Germany.
Some of the documents regarding the equipment were lost, but experts assure that at that time the machine was massive and heavy. Since the 70s, TVSh 3 has become smaller in size. Modern versions of turning equipment are lightweight and easy to install; they are used not in professional activities, but for conducting training courses for beginners. The purpose of the device is to teach turning. A screw-cutting machine allows you to comfortably perform most turning operations, with a minimal degree of error. The fact that it is intended primarily for training is determined by its high degree of safety. Compared to other lathes that are used for identical activities, the risk of injury is many times lower. This quality is ensured by special design changes in the equipment.

Using a lathe, various operations related to material processing are performed. The most common:

• the ability to grind even cones from the material;
• carving with rectangular and square lines;
• formation of bars and beams;
• cutting material;
• cutting off pieces of material to the required size;
• processing the ends of already turned products;
• production of through holes of the selected diameter;
• drilling blind holes.

Of course, in comparison with professional machines, the school version has a limited set of functions. It allows you to carefully examine how the mechanism works, form smooth parts, and thereby hone your level of skill. Students of turning will learn how the tailstock is adjusted, how the cutter works, and what additional parts the lathe is equipped with. In professional models, which are intended for large productions, this is impossible to trace.

The technical characteristics are fully consistent with the intended purpose. The operating sheet states that:

• the maximum diameter of the part that is installed under the caliper area does not exceed 9 centimeters;
• the maximum diameter of the part that is installed above the frame is up to 10 centimeters;
• center-to-center size - 35 centimeters;
• setting the center axis - up to 19 centimeters;
• the maximum diameter of the workpiece being processed is up to 1.4 centimeters (for a rod);
• turning length - 35 centimeters;
• maximum caliper displacement is adjusted - 10 centimeters;
• maximum longitudinal displacement of the caliper is 30 centimeters;
• number of revolutions - from 120 to 170;
• number of speeds - three;
• number of gearbox shift stages - six;
• power - up to 600 W.

The height of the TV 3 lathe is 101 centimeters, length - 143 centimeters, and width - 470 centimeters. The weight without the installed cartridge is about 280 kilograms.

Modern analogues

Despite the reliability and durability of the TV-4 screw-cutting lathe, it has modern analogues that are in no way inferior to the mechanism in terms of functionality and capabilities, these include:

• JET BD-7.
• JET BD-X7.
• Optimum TU1503V.
• Proma SM-300E.
• Triod LAMS-02/300.

The first two models are distinguished by high quality, as well as ease of speed adjustment. These are brands from well-known global manufacturers that can easily compete with TV-4 both in small workshops and on school desks.

The screw-cutting lathe of the Rostov educational equipment plant has been serving faithfully in small workshops and in everyday life for almost half a century. This is a functional and at the same time reliable equipment that will help you master any lathe.

The mechanism is lightweight and small in size and will fit in any mini-workshop. Also, its obvious advantages are ease of operation and durability during service.

Equipment Features

Student metal lathes have bridged the gap between amateur tools and professional production equipment. They received their name Shkolnik for their active use for teaching students in vocational schools and high school students in labor lessons.

All models, from TV2 to the modernized 16U04P with increased accuracy, have common characteristics for school lathes:

• small dimensions;
• simplicity of design;
• safety at work;
• manual control and easy maintenance;
• processing of small-sized workpieces;
• low productivity;
• impossibility of producing batches of parts.

Lathe 16U04P

Training models were produced as floor-mounted ones with cast pedestals and table-top ones with only mounting platforms in the form of wide legs under the frame. They can be installed on a workbench in a workshop and study the principle of operation of a lathe, gaining skills in working as a turner.

The design of the lathe is simplified. There is no gearbox. Speeds are changed by rearranging the gears and flipping the belt. The caliper slide can be moved manually in one direction only. There is no ability to sharpen cones at a given angle.

Taking into account the specificity of Shkolny metal lathes, they were equipped with casings and screens that eliminate the possibility of injury from rotating parts or flying chips. As soon as the guard rose, the cartridge stopped.

There is no space for large-diameter parts in the frame. The maximum workpiece diameter is up to 200 mm. The center-to-center distance on most models is 220 - 350 mm, and only shafts with lengths of 525 and 750 mm can be installed on modernized machines.

Moving the caliper and slide along the dial manually did not allow us to work quickly and make batches of parts. Most Shkolnik series machines have 6 chuck rotation speeds from 120 to 975 rpm. The direction of rotation is switched by the motor.

TV-11 machine diagram

Despite their simplicity, training lathes provide good finishing. They can be used to sharpen parts with an accuracy of 0.05 mm and perform turning for grinding. The gearbox connected to the screw contains thread cutting with 3 pitch sizes on early models and 6 threads on modernized machines, starting with TV7.

Teenagers were taught carpentry on TV4 and on a specially produced wood lathe Shkolnik series STD-120. Using this equipment, those who like to make furniture with their own hands at home make curly legs, stands and other round elements.

Currently, compact lathes are used in mobile workshops to produce parts for repairs. Craftsmen willingly buy compact equipment for home use.