Screw-cutting lathe TV 4. Technical characteristics of the machine. Basic structural elements

27.07.2018

The Rostov specialized plant "Educational Equipment" is engaged in the manufacture and design of the TV-4 lathe. It is designed to develop skills in working with steel billets. Therefore, unlike professional models has a number of distinctive characteristics.

Purpose of equipment

One of the fundamental rules for designing such equipment is its safety and ease of setup. But at the same time with these conditions in the process of work, students must good example familiarize yourself with the design and learn the basic rules for working on a TV-4 lathe.

They are included in our weekly newsletter sent to thousands of engineers. Mounted on a folded bench with built-in coolant, splash guard and brake light switch on the front, the lathe was high quality - and with an impressive specification. Unfortunately, the spindle nose was US specification A1-4, an uncommon fitting in Europe. Without dismantling any gears, threads from 5 to 5 mm pitch can be cut off, and feed rates through a separate drive shaft ranged from 056 to 56 slip and 018-18 lining.

When the carriage was driven, the flywheel could be disengaged, a useful safety feature. - top, tailstock The 3rd Morse Taper had a 120mm hardened and ground spindle engraved with a millimeter ruler, although this class of lathes did not have a micrometer set. If any reader has a Vernier lathe - or another Vernier tool. The sphere also had a wider cross-slip and used plastic not only for the corresponding sheaves and countershaft pulleys, but also for some, but not all examples, change covers and headstock covers and even on some models for the helical screw gear housing and carriage flywheel; unlike the Atlas, it had only one bolt holding the end of the back of the bed, and on the lines it separates the zip nuts and several other small parts of the apron - Raglan apparently saves the cost of costly new dies by using readily available and inexpensive American components .

Initially, the school model was intended to perform the entire range of turning operations. To do this, its design has a classic layout, typical for machines of this type. On TV-4 you can do the following types turning works:

turning and boring of steel blanks by rotation;
trimming ends with high precision;
thread cutting. However, please note that the machine is designed only for forming metric thread;
drilling.

To increase the functionality of the equipment, it is necessary to upgrade it. This can be done only after a detailed study of the specifics of the design and technical characteristics. Each type of modernization should not adversely affect the performance of the machine, the safety of work on it.

Plain head lathes, when properly set up, often give better surface than roller bearing models, but when worn, it is much more difficult and more expensive overhaul. The box is intended to be used while the lathe is running, indeed the manufacturers have stated that this is one of its useful features; however, if you want to have a long and happy life, push the control lever firmly in the desired direction, but do not push it. For clutch dogs on front side gears require a few seconds as a rule, other small metalworking lathes are sold, including popular ones, and which are often mixed with completely different ones.

One of the properties of educational equipment is its layout and location of controls. They are designed in such a way that work on the machine is not difficult due to the short stature or the length of the arms of teenagers.

Design features

Atlas Corporation has published one of the finest training books ever produced by a lathe manufacturer, The Lathe Handbook. It gives a comprehensive description of the machine's potential along with numerous twisting diagrams, clear instructions for general turning and other operations. machining, diagrams, photos and a lot of useful general advice on turning business. Copies, with additional content and reproductions of sales catalogs.

Unfortunately, none of the 10" lathes marked with date stamps and production records are available, and the only way to find out when the machine was built is to check the roller bearings in the headstock: each one is marked with a date stamp and will give a good approximation of when the machine was assembled. Continuation. After setting up and setting up the machine, it can be said that all parts are precisely machined and that the axis between the headstock and tailstock is fully centered and parallel to the machine layer.

To increase the degree of reliability of the machine, its pedestal is made of thick-walled sheet steel with additional stiffening ribs. This design allows you to place the controls and the main working units of the unit as ergonomically as possible.

The basis of the design is the cabinet. In its rear part there is an electric motor, which is necessary to drive the headstock. On the front panel there is a control unit for the operation of the machine - buttons for on / off and activation of the reverse mode. All electrical equipment is mounted in the back of the cabinet. For preventive and repair work it has an access door.

Caution: The device is not suitable for switching on and off directly from the "quick" package on the table. If you look at the included manual and also get some technical knowledge about the machinery, the finished device will be very nice and will work very accurately. This approach is the recommended one for me because you get such a perfectly easy to handle mechanic that, at best, performs great afterwards on the stub with the least play possible.

This device is recommended for model builders and amateur bikers with high demands. For the "newbie" in the field of turning, it should be mentioned that the manual certainly facilitates the handling of the machine and ensures correct use.

Description of the main elements of the TV-4 universal lathe:

. Installed on the left side of the bed. To switch speeds, a box is connected to it. Structurally, they are a single component. Spindle rotation is transmitted by three-jaw chuck;
transmission mechanism. Performs the functions of transmitting rotation from the spindle unit to the gearbox. The gear ratio for this model is ¼. The specificity of the design is the impossibility of installing other pairs of gears, so the gear ratio in this case is a constant;
Transmission. To adjust the feed level, turn the appropriate handle. In the scheme of work, the possibility of simultaneous rotation of the roller and the lead screw is excluded. The trough located in the upper part is necessary for supplying lubricating fluid.

During operation, it is necessary to constantly monitor the oil level for lubricating the gearbox. There should always be at least a minimum amount of liquid in the trough. Otherwise, there is a possibility of overheating and breakage of the gears during the operation of the machine.

Basic structural elements

A set of sponges was used by Gude. After 15 minutes of operation, the engine burned, although only a thin iron rod 1 cm thick was weakly disabled. The motor is not suitable for continuous loads. You have to run for a long time, however, due to lack of power, it can only be canceled weakly. The usual purchase of an engine is meaningless due to the poor quality of the engine. Also, the gears are plastic and will probably throw a spirit next. Maybe one, but for 100 euros from metal nachkaufen. The price is great, so two more stars.

For clarity, on the front of the machine there is a table with possible speeds. This allows you to select the optimal mode of operation before turning the workpiece.

Machine Specifications

To get acquainted with technical parameters training universal lathe, you must study the proposed instructions. Since work on this type of equipment is often performed by unqualified personnel, special attention should be paid to the recommended operating modes.

But only for people who can repair themselves. Who makes a lot, should buy better. In fact the lathe earned 5 stars, but the instruction manual does not important detail. According to this service, other customers encountered the problem that the turning machine did not turn on. Only the speed controller needs to be set to zero to turn on the power, as does the direction switch. Only then can you turn on the switch and then control the speed. Of course, the protective valve for the chuck also needs to be folded.

The TV-4 screw-cutting lathe has a total weight of 280 kg, including all equipment components. At the same time, its dimensions are 144 * 47 * 102 cm. Such characteristics are optimal for installation in confined spaces educational workshops. To transmit torque to the components of the machine, the design has a three-phase electric motor with a power of 1 kW. It is designed to be connected to a 380 V power supply. If it is necessary to adapt the machine to work from a 220 V network, it is necessary to change the power unit or install a special unit.

Structural units of the machine and their characteristics

The guild is now six months old. The more complex, the harder the material is harder. However, it is surprising that with good maintenance, care and expertise the results can be quite impressive. Enter each of the above items have their own book. Perhaps, however, turning steels, but do not make sense with a small turn, since high speed and feed are needed. It can only recommend to those model builders who are looking into the matter and making some improvements, but then it has inexpensive but reliable twists that can do a lot more than you expected.

Lathe TV-4 has the following main characteristics:

maximum workpiece diameter. Above the bed, it should not exceed 20 cm, above the caliper - 12.5 cm;
allowable length of the workpiece - 35 cm;
turning length is 30 cm;
the dimensions of the tool holder are designed to install a tool with dimensions of not more than 10 * 12 mm;
diameter through hole in the design of the spindle - 1.6 cm. This makes it possible to install a bar with a cross section of 15 mm;
the number of feet in forward and reverse rotation is 6;
values options revolutions - 120, 160, 230, 375, 500 and 710 rpm;
longitudinal movement of the caliper is possible to a maximum distance of 30 cm;
lateral movement of the caliper - by 10 cm;
the design of the incisor sled allows for a displacement of 5 cm;
the amount of rotation of the sled with a fixed cutter is ±45°;
the caliper has 3 degrees of longitudinal feeds;
parameters for the formation of metric threads. The allowed number is 3. The step limits are limited to 0.8, 1 and 1.25 mm;
displacement of the tailstock quill up to 6.5 cm.

In the design of the machine there are no mechanisms for forced braking of the spindle and blocking of the control sticks. Therefore, the stop of the workpiece is quite slow. This must be taken into account when planning the operation of the equipment.

Considering the top spins prices in a size that is worth a few costs, he will earn a lot for his money. Main switch with restart and emergency stop function. With practical multiple steel holder and 2 steel holders. Aluminum handwheels with adjustable steel graduation ring. Switch clockwise, counterclockwise and off. Lead screw release switch. Handwheel for fast support adjustment. Grid frame made of gray cast iron.

The design of the main nodes

With polished prism guide with wide foot for support and tailstock. Support screw with trapezoidal thread. Upper height above support 58 mm. For machining steel, brass, aluminum and plastic. For stuffing, longitudinal turning, tapping and threading. With comprehensive system accessories, you can also drill, mill and braze.

The accuracy class of the machine corresponds to the value "H". This makes it possible to process steel parts on it to achieve optimal quality. Limitation - turning workpieces from carbide materials.

Operating rules

Machine: Made of high quality machine casting, transversely ribbed, with prism guide. For vibration-free operation even under high loads. Covered lead screw. Head: made of die-cast aluminium. Rotary switch for automatic feeding. Conductive and traction spindle with trapezoidal thread.

The device and technical characteristics of the machine

Pylon Ø 24 mm, retractable up to 40 mm. Support: Die-cast zinc pads. Crosses and top plates made of steel. Top hinge for tipping. With several steel holders and two steel holders for quick replacement and easy height adjustment.

Since the machine for metal belongs to the class of educational equipment, its installation, adjustment and operation must be carried out by qualified professionals. Before the work process, students are required to get acquainted with the design of the equipment, its technical characteristics, as well as safety rules.

Drive: Powerful capacitor motor for two speeds and optional three-stage belt drive. For this purpose, chuck protection with safety shutdown. Flywheels: made of aluminium, with 0 graduated ring. Quick adjustment support: by large hand wheel through the post attached to the bed.

Threader: For left and right hand threads. Motor power input 870W, output power 550W. The main equipment includes several steel holders with two inserts. Manufactured from 1.5mm thick sheet steel, powder coated. The welded sheet protects the lathe engine.

To install the equipment, it is necessary to equip the foundation with a height of 100 mm. To do this, you can use wooden blocks or make concrete base. Since the design of the TV-4 machine does not provide for level adjustment mechanisms, special attention should be paid to the absence of platform height differences. An alternative option is to install special adjustable supports.

Axial spindle play

Note. The lathe shown here is not included. 4-jaw chuck, centering jaws not individually adjustable. 4-brazed chuck with individually adjustable jaws. Ideal for clamping angled and asymmetrical workpieces. Each jaw can be adjusted individually. Unlike the centering gripping chuck, workpiece centering must be done manually.

Face plate with clamping claws Installed in place of the swivel chuck. For machining round workpieces with high precision. 9 Hardened collets. For a rounding accuracy of 0.02 mm, exactly like a chuck. Additionally 1 unhardened self-learning collet. Instead of a chuck, a corresponding collet chuck is installed.

Besides, important points machine operation are:

preparation for work. The equipment is cleaned of anti-corrosion liquid, the container is filled with lubricating fluid for the gearbox. When connected to the mains, a ground loop is necessarily equipped, an RCD is installed;
work on the machine. First you need to check that all the handles are in their original position. After that, you can proceed to the preliminary settings for turning. The workpiece is fixed between the front and rear headstock, the location of the cutter is set using the mechanisms of the tool holder;
prevention. After the work is completed, chips and metal dust are removed without fail, the integrity and correct functioning of the main components and assemblies are checked. The oil level is checked before starting.

Training lathe model TV-4 is not designed for mass production. Therefore, the degree of its load should be controlled.
For this purpose, a threaded driving pin for screwing into the flange part of the main spindle on one side and for transferring the workpiece using a long hole in the drive disk. With fixture for mounting on bed prisms. For machining longer workpieces and especially for turning them off when the tailstock cannot "oppose".

Important for longitudinal turning of relatively long and thin workpieces. V wooden box with sliding cover. Numerous steel holders incl. two steel holders. For quick steel changes and easy height adjustment. A set of 5 pieces of black steel, steel steel, pointed steel, side steel on the right and side steel on the left.

The video shows detailed overview models:

The Rostov Combine of Educational Equipment began to produce the TV 4 school lathe back in the early 1970s. To this day, it is used to teach schoolchildren and students, and is also often found in personal workshops and small businesses. This versatile device has many positive feedback users and suitable for hobbies. It allows you to perform tasks such as:

3 piece set for external thread for carving, internal thread and drilling steel. Allows cutting blanks and grooves of grooves. Spare knife for cutting steel holders As described above. Set with one centering drill 2-2.5 and 3.15 mm each.

Each 1 piece Grooves - 1, 3 - 2, 65 and 4 mm. In wooden box with sliding lid. Holders for cylindrical grinding on lathes. Parallel support kit, 14 pieces. For installation work for drilling, turning and milling machines. Made from high alloy, hardened steel.

turning surfaces of cylinders and cones - internal and external;
end processing;
threading with a cutter or tap;
segment;
drilling holes.

The operation of the unit is carried out by rotating the blank in the cartridge or centers. The main working shaft of the device rotates due to a belt drive received from an electric motor. When performing turning operations, the cutters are brought to the workpiece due to a secondary feed motion.

TV 4 lathe and its device

The device consists of several elements, including:

Rear support with placed in it electrical equipment.
Front support with an electric motor placed in it.
The stable base of the device, placed on two supports, on whose front part there is a rail and a movable screw.
The feed box sets the amount of feed when threading, which allows you to get the desired pitch. In order for the box to function stably, it is necessary to monitor the presence of lubricant in a special trough.
Unit nodes. The front node provides a connection between the rotation mechanisms and the blank being processed. The other end of the processed blank is attached to the back node.
The main working shaft (spindle) is located in the front assembly. Rotates the processed blank, due to the three-jaw chuck, and has 6 speed values.
Electrical equipment, which includes: lighting transformer, fuses, motor and electrical panel.

Governing bodies

shaft speed setting is performed by two handles located on the front assembly;
the direction of feed for threading is made by a handle located on the front assembly;
feed rates and thread pitches are set using a knob located on the front assembly;
the running shaft is switched by the handle located on the front assembly;
manual movement of the carriage in the axial direction is carried out using a flywheel located on the apron;
the rack and pinion gear is turned on by a button located on the apron;
axial feed of the caliper is switched on by a handle located on the apron;
the lead screw nut is started by the handle located on the apron;
manual movement of the cross slide is carried out using a handle located on the apron;
the tool holder is fixed with a handle located on the apron;
the quill of the rear node is fixed with a handle located on the rear node;
longitudinal movement of the quill is carried out using a flywheel located on the rear node;
the lighting transformer is located on the rear cabinet of the device;
local lighting is turned on and off using a switch located on the rear pedestal;
the safety block is located on the rear pedestal;
the magnetic starter is located on the rear pedestal;
reverse start of the machine is carried out using a button located on the front pedestal;
the lamp is located on the front node;
installation of the rear node to the guides is carried out using the handle located on the rear node;
the mains switch is located on the rear pedestal;
the protective element is located on the apron.

Basic structural elements

Feed box - with the help of a guitar with interchangeable gears, the box receives a rotational effect, and its device provides threading of different pitches. The handle starts the drive shaft or propeller. The gear, moving, disengages from another gear and engages with a clutch that transmits rotation to the shaft. The launch of the screw and the shaft at the same time is excluded by the design.
The front node - otherwise called the gearbox, the node is located on the left side of the unit. The main shaft rotates under the influence of an electric motor using a wedge-time transmission. In the front node there is a cartridge that fixes the blank being processed. The rotation is transmitted through a fixed spur gear located on the shaft to a shaft with a block gear and a fixed gear. The handles move the movable gears located on another shaft, which mesh with other gears, transmitting rotation to the spindle.
Guitar - this element transmits rotation from the main shaft of the gearbox to the gearbox and consists of gears located on the bracket.
Apron - produces a perpendicular feed of the caliper by the running shaft and axial - by the lead screw (mechanical or manual). Manual feed is done by handwheel. A gear wheel is located on the shaft, which engages with a rack and pinion gear located on the roller and mounted on the frame.
Caliper - the element moves the cutters with the help of 4 carriages (moving along the guides of the base; moving along the perpendicular guides and moving the cutter in the transverse direction; turning in both directions from the central position; moving in the axial direction along the guides of the carriage in which the tool holder is fixed).
Rear node - supports the second end of the processed blank. The body of the node is located on the basis moving along the guides of the frame. Inside there is a quill, whose movement in the axial direction is carried out by a flywheel.

Specifications

Training screw-cutting lathe TV 4 according to the passport has the following parameters:

the diameter of the processed blank is 20 cm;
turning diameter over the caliper - 12.5 cm;
the diameter of the processed rod is 1.5 cm;
distance between centers - 35 cm;
turning length - 30 cm;
spindle speed - 120-170 rpm;
longitudinal feeds - 0.08-0.012 mm / rev;
metric thread pitch - 0.8; 1; 1.25;
hole diameter - 1.6 cm;
dimensions - 110x47x102 cm;
weight - 280 kg.

Video: review of the TV 4 lathe.