Attachments for lathes make it possible to facilitate some work and expand functionality serial machines. The devices can be factory-made, produced by some companies, or they can be home-made. In this article I will describe several interesting devices, which will be very useful to any craftsman who has a lathe in his workshop, and most of the devices can be made with your own hands.

Homemade devices for lathes.

Milling attachment for a lathe .

Let's start with perhaps the most necessary and useful device, which will help turn an ordinary lathe into a milling machine and significantly expand the capabilities of any master. This homemade milling attachment is designed for the TV-4 lathe and similar schoolchildren. But such a device is easy to make for anyone lathe, adjusting the dimensions to the dimensions of a specific caliper.

This one is simple but reliable design milling attachment was developed back in Soviet years and published in the magazine “Modelist Constructor”. And with the help of this attachment, you can mill planes on a lathe, process various parts along the contour, and select various grooves and grooves.

And in general, it is possible to process any surfaces of parts with end and face mills, due to the fact that the carriage and support of the machine move in three coordinates, the carriage moves in a vertical plane, and the attachment bracket moves in horizontal plane.

As can be seen from the drawings, the main part of the device is a bracket that is attached to the support of the lathe, instead of the removed carriage (slide) of small longitudinal feed. And the small longitudinal feed carriage itself is removed from the machine support and secured with two bolts on the front wall of the attachment bracket vertically and allows vertical movement of the workpiece.

The tool holder can be used to secure in it not a cutter, but some kind of flat part to be milled. Or you can remove the tool holder and use some kind of homemade vise instead, if the workpiece is more voluminous.

Also, instead of a tool holder, you can attach not a vice to a standard pin, but a chuck from a small lathe, if the part being milled is cylindrical and not flat. Or, instead of a chuck, use the faceplate from the lathe kit. And it is the option with faceplate 3 (with clamps 4) that is shown in the drawing below.

The faceplate is mounted on a standard pin for the tool holder and clamped with a nut. Well, the workpiece is already clamped in the faceplate using clamps 4, as usual. In general, there may be several options for securing the workpiece, depending on its configuration and size.

The bracket for the attachment is cut out with a grinder from ordinary sheet steel 8 mm thick and then its front wall 1, side walls 2 and base 3 are welded together by electric welding. When welding, of course, we always take into account that right angles are maintained.

When the bracket is welded, using drills and cutters we make a central hole and holes for attaching the bracket to the machine support, using standard M8 studs and nuts. To center the bracket on the machine support, use a guide washer 4, which is welded to the bottom plate and is clearly visible in the upper drawing.

Thanks to the semicircular grooves in the front wall of 1 bracket, which are made at 30º in each direction, it will be possible to scroll the fixed carriage and the part in a vertical plane at the same 30º in different sides, which expands the possibilities of processing parts with a milling cutter at different angles.

And thanks to the standard grooves in the caliper, the entire attachment can be rotated in a horizontal plane, using the standard scale in degrees on the caliper. In general, it will be possible to scroll and clamp the workpiece in both planes, and to move it during processing in both the vertical and horizontal planes.

The cutter for processing the part is fixed in the standard chuck of the lathe, and if the cutter has a tapered shank that matches the Morse taper in the spindle of your machine, then you can remove the chuck and fix the cutter directly in the spindle of the machine.

And in order to make accurate tracking of the movement of the cutter, it would not hurt to make a tablet holder for drawings 7, along which the tracking pointer 8, mounted on the machine support and which is shown in the figure, will slide.

By making such a simple device, you will significantly expand the functionality of your lathe.

Milling attachment for processing round timber (cylindrical blanks).

Well, if you need, for example, to make a square or a hexagon out of round timber, or to cut a keyway on some shaft, then for these operations you can make a simpler milling attachment based on lathe chuck and some pieces of iron. Anyone can see how I made it from garage trash and how it works in the video below, or on my YouTube channel suvorov-custom. Enjoy watching everyone.

Device for smooth movement of the tailstock.

This simple device makes it possible to move the tailstock smoothly and with minimal costs. And such a device will be needed, for example, for drilling very deep holes, because the movement of the quill on small machines is only 50 - 60 mm. And if the lathe is large enough, the heavy tailstock can be moved without any effort.

To begin, drill a couple of holes in the side of the tailstock plate and cut an M10 or M12 thread into them with a tap. Next, using these holes, we bolt to the tailstock plate a homemade corner bracket 1 (see figure) in which rollers 4 and 5 rotate. Drive gear 3 and drive handle 2 are mounted on roller 4.

And on the roller 5 there are driven gears 6 and a wheel 7 of smaller diameter, which rolls along the standard gear rack of the machine bed and thereby drives the tailstock of the machine. If desired, you can also make a small casing from tin or sheet plastic that will cover the gears, which it is advisable to lubricate, from dust.

Device for fixing drills on a machine support .

This lathe attachment will also be useful if you need to drill fairly deep holes long drills. In addition, it will allow you to quickly and periodically remove the drill from the hole to remove chips and lubricate the drill.

After all, the speed of movement of the tailstock quill is very small, and the speed of longitudinal movement (mechanical feed) of the caliper is much higher. And this device will improve the productivity of drilling parts, especially if there are a lot of them and if the depth of the holes is significant.

The basis of the device is drill holder 1 (see figure), which is fixed in the tool holder of the machine. The holder has a tapered hole to accommodate the tapered shank of a drill chuck or a drill with a tapered shank.

Of course, the axis of the conical hole of the drill holder (or chuck) must coincide with the axis of the lathe headstock spindle. The same should be taken into account when securing the drill holder in the tool holder of the machine. Since the slightest misalignment may reduce the quality of drilling, break the walls of the hole and even break the drill.

Feed when drilling holes in parts is carried out by longitudinal movement of the caliper slide. And the advantage of this device, as mentioned above, is a higher movement speed cutting tool, especially when you have to drill deep holes and have to frequently remove the drill to remove chips.

When making such a drill holder, it is not necessary to make its body cylindrical as in the figure; you can make the body in the form of a bar and it is much easier to make it on milling machine. But you can also make a cylindrical body on a lathe, and then weld a plate 10-15 mm thick to it on the side, for which the device will be clamped in the tool holder of the lathe.

Improved die holder design .

When cutting threads with dies that are installed in conventional die holders, the cut thread often turns out Bad quality due to misalignment of the cutting tool. To avoid this, you have to always support the regular die with the tailstock quill before cutting the thread.

However, it is much faster and more convenient to work when cutting threads using an improved die holder, which you can make yourself on the same lathe. The figure on the left shows one of the designs of such a die holder.

Mandrel 1 with its conical shank is inserted into the conical hole of the tailstock quill. The mandrel is free (but with minimum clearance) a glass 2 and a replaceable sleeve 4 are installed, in which the die is secured with a screw. Tailstock with the tool is brought to the rotating workpiece. Further movement of the tool is carried out by moving the quill.

When it comes into contact with the part, glass 2 is kept from rotating by handle 3, on which, by the way, you can put a tube and rest it against the machine bed. Glass 2 moves freely along mandrel 1 during thread cutting. Upon completion of thread cutting, the rotation of the machine spindle is reversed and the tool moves away from the part.

For those who do not have a machine with low speeds, it is best to cut threads by rotating the machine spindle manually, using a chuck or using a special handle that is inserted into the back of the spindle.

Device for simultaneous drilling and tapping .

A device for a lathe that allows you to simultaneously drill a hole and cut an external thread in one installation of the tool is shown in the figure below.

Mandrel 4 of this device is also inserted into the tailstock quill of the lathe. In the front part of the mandrel there is a socket for securing the drill. And the outer movable mandrel 2 is put on the mandrel 4 and moves along it in the axial direction. Key 3 keeps it from turning.

In the front part of the outer mandrel there is a hole for a replaceable sleeve with a die and there is a screw 1 securing them. After the inner mandrel is inserted into the tailstock quill, ring 5 with handle 6, outer mandrel 2 are put on the mandrel, and the drill and die are inserted.

At the end of drilling, without removing the drill from the hole, we switch the spindle speed to a number that corresponds to thread cutting. The outer mandrel is fed by hand from right to left. In this case, the thread turns out to be correct and concentric with respect to drilled hole. Upon completion of thread cutting and when the direction of rotation of the machine spindle changes, the outer mandrel moves vice versa from left to right.

Another simple but useful homemade adapter device is described here and it will help to secure a thicker cutter that does not fit into the standard tool holder of a lathe.

Well, in conclusion about homemade devices for lathes, I publish just below another video from my channel suvorov-custom, in which I show another simple, but very useful device, with which you can very quickly center the workpiece and then finally clamp it exactly in the chuck of the lathe.

Factory fixtures for lathes.

There are quite a lot of factory devices, but I will describe the most common and useful ones.

Universal cone ruler .

It is used for machining conical surfaces on a lathe. The ruler is installed parallel to the generatrix of the conical surface, and top part The lathe support rotates 90 degrees.

The angle of rotation of the cone ruler is measured using the divisions (millimeter or angular) marked on the scale. The angle of rotation of the ruler should be equal to angle cone slope.

And if the scale of the ruler has not degree divisions, but millimeter divisions, then the amount of rotation of the ruler is determined by one of the formulas published below:

Where h is the number of millimeter divisions of the scale of the cone ruler,

and H is the distance from the axis of rotation of the ruler to its end, on which the scale is not placed. The letter D is largest diameter cone, the letter d is the smallest diameter of the cone, the letter L is the length of the cone, the letter α is the angle of the cone, and the letter R is the taper.

Fixed and movable rests .

Designed for processing non-rigid (thin) shafts. The fixed steady rest shown in the figure consists of a cast iron body 1, to which a hinged cover 6 is fastened with a bolt 4, which makes installation of the part easier. The base of the steady rest body has a shape corresponding to the frame guides, on which it is secured by means of a strip 2 and a bolt 3.

Two cams 8 move in the body using adjusting bolts 9, and one cam 7 moves in the cover. Screws 5 are used to secure the cams in the required position. This device allows shafts of various diameters to be installed in the steady rest.

But much more effective is the modernized steady rest (see figure below), in which the lower hard cams are replaced by ball bearings 8. They are adjusted according to the diameter of the surface being machined using a control shaft located in the center, or according to the part itself.

After this, lower the cover 2 of the steady rest and, using nut 4 to adjust the position of the rod 5, install the cover so that the gap between the base of the steady rest and the cover is 3-5 mm. This position of rod 5 is fixed with locknut 3.

Then, using eccentric 1, the cover is pressed to the base of the steady rest, while under the action of spring 6, the upper ball bearings 7 forcefully press the workpiece. The runout of the part is perceived not by ball bearings, but by spring 6, which serves as a shock absorber.

Movable rests. Unlike fixed steady rests, which are fixed on control machines, there are also movable steady rests (see figure below), which are fixed on the support carriage.

Since the movable steady rest is fixed on the support carriage, it moves along with it along the part being turned, following the cutter. Thus, it supports the part directly at the point where the force is applied and protects it from deflection.

A movable steady rest is used for finishing turning of long parts. It has two or three cams. They are pulled out and secured in the same way as the cams of the fixed rest.

To prevent too much friction, the cams should be well lubricated. To reduce friction, the tips of the cams are made of cast iron, bronze or brass. Better yet, use rollers made of bearings instead of cams.

And in conclusion, those interested can watch in the video below how I saved a special machine from scrap metal high precision 16B05A.

And just below I published a video about a homemade dividing device for my TV 4 lathe, which I made in just a couple of hours.

Well, below we show and talk about the restoration of my TV-4 machine.

That seems to be all. Of course, not all the devices for lathes were published here, but if at least the devices published in this article appear in your workshop, then the capabilities of your workshop will expand significantly, creative success everyone.

When slicing pipe thread 1/2" on water pipes Ah, you have to manually first saw down the lead-in chamfer at the end of the pipe. Next, by rotating the knob with the die and applying quite a significant longitudinal (axial) force to the knob, we achieve the cutting of the die into the end of the pipe. If the force is insufficient or the die is skewed, it is not possible to start threading, so you have to file the chamfer on the pipe again.

Thread cutting device

The simplest device that eliminates these difficulties and allows you to cut a thread without any effort at all along the pipe and even without a chamfer on the pipe is shown in the figure. The die itself is secured in a die holder with two handles. The die holder body has screws that secure the die in it (not shown in the figure). A steel coupling with a 3/4" internal thread is welded to the body. A bushing is made from a piece of pipe with a diameter of 3/4" and a length of 40 mm with three nuts welded to it along the circumference, into which stoppers are screwed (M8 bolts 25 mm long). At one end of the bushing (in a section 18 mm long) a 3/4" external thread is cut, and internal hole The bushing is enlarged to a diameter of 22 mm (by hand, with a file), so that a 1/2" pipe can easily pass through the bushing.

Device for cutting 1/2" threads on pipes:
1 - die; 2 - die holder handle; 3 - die holder body; 4 - coupling with internal thread 3/4"; 5 - sleeve with external thread 3/4"; 6 - lock bolt; 7 - nut;
8 - pipe with a diameter of 1/2".

To cut threads on a 1/2" pipe, a die holder with a coupling is screwed onto the sleeve, and a distance L is set from the end of the coupling to the end of the thread on the sleeve, equal to length cut thread on a pipe with a diameter of 1/2". Next, insert the 1/2" pipe on which the thread is supposed to be cut into the bushing so that the end of the pipe rests against the die, after which the pipe is locked in the bushing with all three stoppers. Now, by rotating the die holder using the handles, screw the coupling (together with the die) onto the sleeve, ensuring that the die moves in increments of t = 1.814 mm (14 threads per inch) without applying longitudinal force and without paying attention to whether there is a chamfer on the pipe or not. This situation occurs because the 1/2" thread on the pipe and the 3/4" thread on the coupling and bushing have the same pitch.

Practice has shown that cutting threads on a pipe with this device is a pleasure. Of course, when cutting threads on a pipe, the latter must be securely clamped in a vice.

Technological advice, failure to comply with which will lead to the device becoming inoperable

1. To ensure the alignment of the die and the coupling, it is necessary to assemble the entire device on a pipe with a diameter of 1/2" with a pre-cut pipe, screw the pipe into the die and only then weld the coupling to the body of the die holder.

2. To ensure the alignment of the threads for the stoppers present in the nuts and cut into the wall of the bushing, you must first weld three nuts, evenly distributing them around the circumference of the bushing, then drill the wall of the bushing, using the nut as a jig (through the nut), and then cut the thread into bushing wall.

The question of how to cut a thread with a tap arises in cases where a pre-made hole needs to be prepared to accommodate a bolt, screw, stud or any other type of threaded fastener. It is the tap in similar situations is the main tool that allows you to quickly and accurately cut internal threads with the required geometric parameters.

Types and areas of application of taps

Cutting internal thread can be done manually or using machines various types(drilling, turning, etc.). The working tools that perform the main work of cutting internal threads are machine-hand or machine taps.

On different kinds Taps are divided depending on a number of parameters. The following principles for classifying taps are generally accepted.

1. According to the method of rotation, a distinction is made between machine-manual and machine taps, with the help of which internal threads are cut. Machine-hand taps equipped with a square shank are used in combination with special device with two handles (this is the so-called knob, tap holder). With the help of such a device, the tap is rotated and cuts the thread. Thread cutting with a machine type tap is carried out on metal cutting machines of various types, in the chuck of which such a tool is fixed.
2. Based on the method by which internal threads are cut, a distinction is made between universal (through) taps and complete taps. The working part of the former is divided into several sections, each of which differs from the others in its geometric parameters. The section of the working part that first begins to interact with the surface being processed performs rough processing, the second - intermediate, and the third, located closer to the shank - finishing. Cutting threads with complete taps requires the use of several tools. So, if a set consists of three taps, then the first of them is intended for roughing, the second for intermediate, and the third for finishing. As a rule, a set of taps for cutting threads of a certain diameter includes three tools, but in some cases, when products made from special hard material, sets consisting of five tools can be used.
3. According to the type of hole, on inner surface which needs to be threaded, there are taps for through and blind holes. A tool for processing through holes is characterized by an elongated conical tip (approach), which smoothly passes into the working part. Taps most often have this design universal type. The process of cutting internal threads in blind holes is carried out using taps, the conical tip of which is cut off and performs the function of a simple milling cutter. This design of the tap allows it to cut threads to the full depth of a blind hole. For thread cutting of this type As a rule, a set of taps is used, driven manually using a crank.
4. According to the design of the working part, taps can have straight, helical or shortened chip removal grooves. It should be borne in mind that taps with grooves of various types can be used for cutting threads in products made of relatively soft materials– carbon, low-alloy steel alloys, etc. If threads need to be cut in parts made of very hard or viscous materials (stainless, heat-resistant steels, etc.), then for these purposes taps are used, the cutting elements of which are arranged in a checkerboard pattern.

Taps are typically used for cutting metric thread, but there are tools that can be used to cut pipe and inch internal threads. In addition, taps differ in their shape work surface, which can be cylindrical or conical.

Preparing to cut internal threads

In order for the process of cutting internal threads using a tap to not cause any particular difficulties and result in a high-quality result, it is necessary to properly prepare for this technological operation. All methods of cutting threads using a tap assume that a hole with the appropriate diameter has already been made in the workpiece. If the internal thread to be cut has standard size, then to determine the diameter of the preparation hole, a special table with data in accordance with GOST can be used.

Table 1. Diameters of holes drilled for standard metric threads

In the event that the thread that needs to be cut does not belong to the standard category, you can calculate the diameter of the hole for making it using universal formula. First of all, it is necessary to study the marking of the tap, which must indicate the type of thread being cut, its diameter and pitch, measured in millimeters (for metric). Then, to determine the cross-sectional size of the hole that needs to be drilled for the thread, it is enough to subtract the pitch from its diameter. For example, if a tool marked M6x0.75 is used to cut a non-standard internal thread, then the diameter of the preparation hole is calculated as follows: 6 – 0.75 = 5.25 mm.

For standard threads belonging to the inch category, there is also a table that allows you to choose the right drill with which to carry out the preparatory work.

Table 2. Diameters of holes drilled for inch threads

An important question to obtain a high-quality result is not only the question of what is used to cut the thread, but also what drill to use to make the preparation hole. When choosing a drill, you need to pay attention to the parameters and quality of its sharpening, as well as to ensure that it rotates in the chuck of the equipment used without runout.

The sharpening angle of the cutting part is selected depending on the hardness of the material that needs to be drilled. The higher the hardness of the material, the greater the sharpening angle of the drill should be, but this value should not exceed 140°.

How to cut threads correctly? First you need to select tools and consumables:

1. an electric drill or drilling machine capable of operating at low speeds;
2. a drill whose diameter is calculated or selected using reference tables;
3. a drill or countersink, with the help of which a chamfer will be removed from the edge of the prepared hole;
4. a set of taps of the appropriate size;
5. hand holder for taps (drivers);
6. bench vice (if the product in which the thread needs to be cut needs to be fixed);
7. core;
8. hammer;
9. machine oil or another composition that during processing must be used to lubricate both the tap and the thread section being cut by it;
10. rags.

Features of the technology

When cutting internal threads with a tap, the following algorithm is used.

• In the place on the surface of the workpiece where the hole for threading will be drilled, it is necessary to form a recess for a more accurate entry of the drill, using a core and a regular hammer. The drill is fixed in the chuck of an electric drill or drilling machine, at which low tool rotation speeds are set. Before starting drilling, the cutting part of the drill must be treated with a lubricating compound: a lubricated tool enters more easily into the structure of the material being processed and creates less friction in the processing area. You can lubricate the drill with a piece of ordinary lard or grease, and when processing viscous materials, machine oil is used for these purposes.
• If it is necessary to cut threads in small parts, they should first be fixed using a bench vice. When starting drilling, the tool fixed in the equipment chuck must be positioned strictly perpendicular to the surface of the workpiece. You should lubricate the tap regularly and ensure that it does not warp and moves strictly in the given direction.
• At the entrance to the hole, as mentioned above, it is necessary to remove the chamfer, the depth of which should be 0.5–1 mm (depending on the diameter of the hole). For this purpose, you can use a larger diameter drill or countersink, installing them in the chuck of drilling equipment.
• The process of cutting internal threads begins with tap No. 1, which is the first to be installed in the driver. We should not forget about the lubricant, which must be applied to the tap for threading. The position of the tap relative to the hole being machined must be set at the very beginning of the work, since later, when the tool is already inside the hole, this will not be possible. When cutting a thread with a tap, you must adhere to next rule: 2 turns of the tap are made in the direction of thread cutting, 1 - against the direction. When the tap makes one revolution back, chips are thrown off its cutting part and the load on it is reduced. Thread cutting with a die is performed using a similar technique.
• After cutting the thread with tap No. 1, tool No. 2 is installed in the driver, and after it – No. 3. They are processed according to the method described above. When cutting threads with taps and dies, you need to feel when the tool begins to rotate with force. As soon as such a moment occurs, you should turn the knob reverse side to clear chips from the cutting part of the tool.

When a pipeline is being repaired, it becomes necessary to insert it into the existing pipeline. If metal pipes are laid, you can use welding. To connect shut-off valves You must have a special tool for cutting threads on pipes. Moreover, its production with such a device can be easily done at home with your own hands.

In most cases, a threaded connection remains the main type of connection metal pipes. It has several parameters that are taken into account when installing the fittings. Correctly selected dimensions allow you to create a reliable and tight connection.

To work with a thread cutter, it is necessary to distinguish between types of thread, its parameters and characteristics.

Inch and metric cutting

Several parameters are considered to be a characteristic difference:

In Russia, all measurements are performed in metric system. Threading a threaded connection was no exception. . The characteristic differences are:

• Dimensions are indicated in millimeters.
• The profile resembles an equilateral triangle.
• A small step.

To connect water pipes, the inch system is used, the manufacture of fasteners is done in the metric system. If the reinforcement is screwed in a clockwise direction, the connection is called right-handed. If on the contrary, the thread is considered left-handed.

Types of tools

For the manufacture of threaded connections, the industry produces special cutting devices. They are designed to perform certain technological operations. A screw-like tool for creating internal threads is called a tap. The device cuts chip grooves on the body of the pipe. For fastening in the driver, the tap has a long shank. The tool is produced in accordance with the current standard. There are special tables that indicate the size of the tap, its number and type.

The cutting kit includes two taps. Their main difference is the depth of groove cutting:

• Chernova - No. 1.
• Finishing - No. 2.

Die device

This device is sometimes called a lerka. The tool is equipped with a kind of nut with several holes. It is this that creates the cutting edges.

The industry produces lerks of various shapes:

• Klupp.
• Round.
• Split.
• Sliding.
• Whole.

Description of the clamp

It differs from other devices in its special guide, which centers the die relative to the pipe. The device can be electric or manual. For use at home, when cutting will occur no more than two or three times, it would be more rational to work with a manual clamp. Its cost is much less than an electric tool.

This tool is very convenient to work with. The thread is very clean and reliable. The light weight of the device and the simplicity of the design allow you to quickly replace the cutters.

TO the most important characteristic The die refers to the material from which it is made. Expensive tool steel is used to create the die. But carving is created only by incisors. They must be highly durable.

The clamp does not have expensive non-functional elements. Therefore, a set of dies costs much less. Cost of cutting threads on a pipe made of of stainless steel decreases sharply. Home craftsmen, not wanting to incur large financial losses, prefer to work with such a tool.

Self-cutting

There are several tools you can use to do the job:

• Tap.
• Die.
• Klupp.

Which tool set to choose depends on several factors. This is especially true for the type of carving. After all, it can be internal or external. After selecting a die, there are several steps to follow.

If everything is in order, the number of turns corresponds to the mating part, you can seal the connection and begin installation of the pipeline system.