Homemade chucks for wood lathes. Homemade lathe chuck. User manual

We make a lathe for metal and wood with our own hands

Now you can buy a lathe for wood and metal to suit every taste (and at any cost). Of course, many of the most modern and additional functions(which most often are not needed).

I don’t argue that a lathe is a very necessary and useful thing for a workshop, but in 90% of cases it is not worth the money spent on it.

We want to help you save your finances. Why buy a model with many unnecessary functions if you can make a standard simple model yourself?

Wood lathe materials

The design itself consists of the following parts (see picture)

  1. The bed is the basis for the machine, usually made of metal and consists of several connected beams.
  2. Transverse U-shaped beam.
  3. Electric motor - serves as a power source for proper movement around its axis (single-phase motors with a power of 200-400 Watt are suitable).
  4. Scroll chuck.
  5. Tailstock support.
  6. An element that rotates.
  7. Support for a workpiece or tool.
  8. Support for the tool rest.
  9. Guide beams.
  10. Angle, post, or support for the tailstock.
  11. Clip.
  12. Metal plate for support.
  13. Cross guide detail.
  14. Screws for fastening.
  15. Support axis.

Wood lathe step by step instructions

First of all, you don’t have to buy a new motor, but take a used one; it will cost you much less.

The elements are fixed to the base (No. 1 according to the figure) 2 U-shaped beams are connected by welding to two transverse ones (No. 2 according to the figure).

The guides on top are additionally fixed with two corners (No. 10 in the figure), which are secured to the main surface.

The engine (No. 3 in the figure) is attached to the side and the headstock is secured.

As the basis of the tailstock, you should use a rotating center (buy a part from a commercial version), attach it to the support (No. 5 according to the figure) and weld it on the platform (No. 12 according to the figure)

The stop (No. 5) is made from a corner and attached to the support (No. 8), which itself is fixed to the holder. The stop and holder are threaded onto the support axis (No. 15) and then welded to the guide beams.

The same stop (No. 5) and the rotating element (No. 6) are fixed on metal plates (No. 12) that contain special moving clips (No. 11).

Please note that the stop and tailstock are moving elements that should move along the guides (No. 9) without any problems.

To ensure that the moving elements are well attached to the clips, preliminary holes are made in the clips (No. 14) and the slightest inaccuracy reduces the quality of operation of the entire device.

The welding itself may lead to deformation of the material - first all materials are held together spot welding, and then carry out the full work.

Wood lathe video

Metal lathe materials

To make such a tool you will need:

  • Metal sheet;
  • U - shaped metal beams;
  • Steel strips;
  • Steel corners;
  • Electrical engine;
  • Transmission mechanism;
  • Several nuts and bolts for fastening;
  • Bulgarian;

Separately, it is worth mentioning about the engine, it does not have to be new, you can limit yourself to an old or used one, its power should be 2 kW with a number of revolutions per minute within 2000. Although this depends more on the level of your work on this machine.

The more massive the workpieces, the more powerful the engine should be if you want to make a compact machine with low power– even a motor from a washing machine or electric drill will do.

As for the transmission mechanism, you can find it on the Internet or buy an old gearbox from friends and remove the clutch from the box. Thus, you will get a mechanism that creates several speeds for your machine. And if you install an additional pulley, you can improve the number of revolutions.

Metal lathe step by step instructions

The installation should begin by using steel corners and a U-shaped beam, from which (1 corner and 1 beam) you need to weld a frame for the base.

To do this you need to wedge the base. The guides are assembled from square pipes and steel strips.

In addition to this metal sheet, they make a box for the fist chuck; after installation, adjustable bearings are placed in it.

The tailstock must be welded from a corner and a thick plate, the support of which will be the guides.

The headstock should move easily and freely along the guides. Weld nuts to the top of the headstock (to secure the supporting center).

The sharpened cone should be mounted into the beam, while maintaining maximum accuracy. Such a cone can be made from any bolt that suits your size.

After this, the entire structure is assembled, the spindle is checked for ease of rotation, and the front and rear centers are adjusted to create a level axis.

Now you know that building a machine for wood or metal is quite possible and requires little knowledge and effort from you, and at the same time it will cost you much less (and even if it breaks, you can fix it yourself).

In general, making such a machine will help you even if you do not often do such work; only such mechanisms are very bulky and you need a place to store them (or you can make “pocket” models).

Metal lathe video

Do-it-yourself homemade metal lathe: drawings, photos, videos

Many home craftsmen are thinking about how to make their own metal lathe. This desire is explained by the fact that with the help of such a device, which will be very inexpensive, you can effectively perform a large range of turning operations, giving metal workpieces the required dimensions and shape. It would seem much easier to purchase a simple tabletop machine and use it in your workshop, but given the considerable cost of such equipment, it makes sense to spend time making it yourself.

A homemade lathe is quite possible

Using a lathe

A lathe, which was one of the first to appear in the line of equipment for processing parts made of different materials, including metal, allows you to produce products of various shapes and sizes. Using such a unit, you can turn the outer and inner surfaces of the workpiece, drill holes and bore them to the required size, cut the outer or internal thread, perform knurling in order to give the surface of the product the desired relief.

A serial metal lathe is a large device, which is not so easy to operate, and its cost is very difficult to call affordable. Using such a unit as a desktop equipment is not easy, so it makes sense to make a lathe for your home workshop yourself. Using such a mini-machine, you can quickly turn workpieces made not only of metal, but also of plastic and wood.

Such equipment processes parts that have round section: axles, tool handles, wheels, structural elements of furniture and products for any other purpose. In such devices, the workpiece is located in a horizontal plane, while it is given rotation, and the excess material is removed by a cutter securely fixed in the machine support.

Grooving a brake disc on a homemade lathe

Despite the simplicity of its design, such a unit requires clear coordination of the movements of all working parts in order for processing to be carried out with the utmost precision and the best quality of workmanship.

An example of a homemade lathe with drawings

Let's take a closer look at one of the working options for a lathe assembled on our own, quite high quality which rightfully deserves the closest attention. The author of this homemade product did not even skimp on the drawings, according to which this device and was successfully produced.

Of course, not everyone needs such a thorough approach to business; often more simple designs, but as a donor for good ideas This machine fits perfectly.

DIY lathe

Appearance of the machine Main components Caliper, tool holder and chuck
Side view of the tailstock Bottom view of the tailstock
Guide shafts Caliper design Engine drive
Drawing No. 1 Drawing No. 2 Drawing No. 3

Structural units

Any lathe, including a homemade one, consists of the following structural elements: a supporting frame - a bed, two centers - a drive and a driven, two headstocks - front and rear, a spindle, a support, a drive unit - an electric motor.

Design of a small-sized metal lathe

All elements of the device are placed on the bed; it is the main load-bearing element of the lathe. The headstock is a stationary structural element on which the rotating spindle of the unit is located. In the front part of the frame there is a transmission mechanism of the machine, with the help of which its rotating elements are connected to the electric motor.

It is thanks to this transmission mechanism that the workpiece being processed receives rotation. The tailstock, unlike the front one, can move parallel to the direction of processing; it is used to fix the free end of the workpiece being processed.

A simple diagram of the components of a homemade woodworking machine will suggest a simple option for making a bed, headstock and tailstock

A homemade metal lathe can be equipped with any electric motor, even if it is not very powerful, but such a motor can overheat when processing large-sized workpieces, which will lead to its stop and, possibly, failure.

Typically, electric motors are installed on a homemade lathe, the power of which is in the range of 800–1500 W.

Even if such an electric motor has a small number of revolutions, the problem is solved by choosing an appropriate transmission mechanism. To transmit torque from such electric motors, belt drives are usually used; friction or chain mechanisms are very rarely used.

Mini-lathes, which are equipped in home workshops, may not even have such a transmission mechanism in their design: the rotating chuck of the unit is fixed directly on the electric motor shaft.

Direct drive machine

There is one important rule: both centers of the machine, driving and driven, must be located strictly on the same axis, which will avoid vibration of the workpiece during its processing. In addition, it is necessary to ensure reliable fixation of the part, which is especially important for frontal-type models: with one leading center. The issue of such fixation is resolved using a jaw chuck or faceplate.

In fact, you can make a lathe with your own hands with a wooden frame, but, as a rule, metal profiles are used for these purposes. High rigidity of the lathe frame is required so that the accuracy of the location of the driving and driven centers is not affected by mechanical loads, and its tailstock and support with the tool move freely along the axis of the unit.

The use of channels in the manufacture of the frame and headstock of the machine

When assembling a metal lathe, it is important to ensure reliable fixation of all its elements, be sure to take into account the loads to which they will be subjected during operation. The dimensions of your mini-machine and what structural elements it will consist of will be influenced by the purpose of the equipment, as well as the size and shape of the workpieces that are planned to be processed on it. The power of the electric motor, which you will need to use as a drive, will depend on these parameters, as well as on the size of the planned load on the unit.

Option for bed, headstock and drive

To equip metal lathes, it is not recommended to choose commutator electric motors that differ in one characteristic feature. The number of shaft revolutions of such electric motors, as well as the centrifugal force that the workpiece develops, increases sharply as the load decreases, which can lead to the part simply flying out of the chuck and can seriously injure the operator.

Such electric motors can be used if you plan to process small and light parts on your mini-machine. But even in this case, the lathe must be equipped with a gearbox that will prevent an uncontrolled increase in centrifugal force.

Asynchronous three-phase electric motor connected to a 220 Volt network through a capacitor

It has already been proven by practice and design calculations that for turning units that will process metal workpieces up to 70 cm in length and up to 10 cm in diameter, it is best to use asynchronous electric motors with a power of 800 W or more. Engines of this type are characterized by stable rotation speed when there is a load, and when it decreases, it does not increase uncontrollably.

If you are going to make your own mini-machine for metal turning, then you should definitely take into account the fact that its chuck will be affected not only by transverse but also longitudinal loads. Such loads, if a belt drive is not provided, can cause destruction of the electric motor bearings, which are not designed for them.

If it is not possible to use a belt drive, and the driving center of the device is directly connected to the electric motor shaft, then a number of measures can be taken to protect its bearings from destruction. A similar measure can be a stop that limits the longitudinal movement of the motor shaft, which can be used as a ball installed between the electric motor housing and the rear end of its shaft.

The tailstock of the lathe houses its driven center, which can be stationary or freely rotating. The simplest design has a fixed center: it is easy to make on the basis of a regular bolt, sharpening and grinding the part that will come into contact with the workpiece to a cone. By screwing or unscrewing such a bolt, moving along a threaded hole in the tailstock, it will be possible to adjust the distance between the centers of the equipment, thereby ensuring reliable fixation of the workpiece. This fixation is also ensured by moving the tailstock itself.

In order for the workpiece to rotate freely in such a fixed center, the pointed part of the bolt that comes into contact with it will need to be lubricated machine oil before starting work.

Homemade tailstock for benchtop lathe

Today it is not difficult to find drawings and photos of lathes from which you can independently make such equipment. Moreover, it is easy to find various videos demonstrating the process of their manufacture. This could be a mini CNC machine or a very simple device, which, nevertheless, will give you the opportunity to quickly and with minimal labor input produce metal products of various configurations.

The stands of a simple metal lathe can be made from wood. They will need to be securely fastened to the unit frame using bolted connections. If possible, it is better to make the frame itself from metal corners or channels, which will ensure its high reliability, but if they are not at hand, you can also choose thick wooden blocks.

The video below shows the process of making a lathe support yourself.

As a unit on a machine on which it will be fixed and moved cutting tool, a tool rest will appear, made from two wooden planks connected at an angle of 90 degrees. On the surface of the board where the tool will be placed, it is necessary to fix a sheet of metal that will protect the wood from deformation and ensure the exact location of the cutter in relation to the workpiece. It is necessary to make a slot in the supporting surface of the horizontal plank moving along the frame of the unit, due to which such movement will be quite accurate.

To make the headstock and tailstock of your homemade lathe, you will need to select metal cylinders of appropriate size, which are placed in bearing units installed in wooden racks. The rotation performed by the workpiece will be transmitted to it through the front center, connected by a belt drive to the electric motor. Thus, the workpiece, securely fixed between the front and rear centers, is processed using a cutter installed in the equipment tool rest.

Another version of a homemade machine (click to enlarge)

General view Headstock Caliper and chuck

There should be no problems finding an electric motor that should be equipped with a mini-lathe. Even if you were unable to find a motor of the required power (500-1000 W - for processing small parts, 1500-2000 W - for large-sized workpieces), then a previously used unit, previously installed on a household appliance, is quite suitable. sewing machine. In addition, it is permissible to use electric drills or grinders as a drive for compact lathes.

As a result of such simple manipulations, you will have at your disposal a machine capable of performing the most common metal turning operations. If desired, the unit can be upgraded, expanding its functionality. Of course, it is difficult to make a CNC machine from such a device, but it is quite possible to perform boring, drilling, grinding, threading and a number of other technological operations on metal.

DIY lathe chuck

The quality and performance of any equipment depends directly on the condition of its equipment. It is especially important to accurately, quickly and reliably secure workpieces on CNC machines and machines that operate as part of the GPS. To reduce the time required to position the workpiece on the machine, as well as to increase the reliability and accuracy of its fastening, chucks for lathes are widely used.

Features of the lathe chuck

A lathe chuck is an integral part of the equipment complex when carrying out turning operations. This structural part is intended for securing piece workpieces and bar material on screw-cutting lathes, grinders, turret and lathes, as well as metalworking equipment. With a lathe chuck you can clamp workpieces of a wide variety of sizes. The workpieces are attached to the inner plane of its hole, the outer surface or the outer surface for the shaft.

Lathe chucks with mechanized drives make it possible to reduce the auxiliary time required to install a workpiece on equipment and remove it after processing, thereby increasing labor productivity. On the other hand, these products increase processing accuracy, as they ensure coordination of workpieces relative to the working parts of the lathe and their reliable fastening, which eliminates deformation or displacement during processing.

Some of the world's most famous manufacturers of wood lathe chucks in Europe are Rohm (Germany), Bison-bial (Poland), as well as some domestic factories of technical equipment, tools and machine components. These products are quite expensive, but today it is simply impossible to imagine production without the use of lathe chucks.

Operating principle of lathe chuck

The lathe chuck must be used in indoors and in the absence of aggressive substances that provoke corrosion. Before starting work, the tightening bolts are tightened to the maximum with a wrench, then the lathe chuck is secured on the machine, all bolts are tightened with nuts and the lathe is started. It should be taken into account that low speeds are set to begin with to check the values ​​of the end and radial runout of the lathe chuck at idle speed.

For fastening products on lathes, two- and three-jaw chucks are widely used, less often - four-jaw chucks. To fasten and hold parts, the lathe chuck contains cams, the number of which varies from 2 to 6. In this case, lathe chucks come with independent movement of the cams and with direct attachment of the cams to the flange end of the spindle. Depending on the method of fastening the lathe chuck to the machine, the following types of fastening are distinguished: on the flanged end of the spindle, through the adapter flange, directly on the lathe spindle itself.

Centering the workpiece in the chucks is achieved by simultaneously moving the clamping jaws in the radial direction. The cams of the lathe chuck move simultaneously with the help of a disk, which has grooves in the form of an Archimedean spiral on one side and a bevel gear, which is associated with three others, on the other. The key sets one wheel in motion, at the same time the disk also turns and moves all the cams evenly. The direction of rotation of the disk will determine whether the jaws approach the center of the chuck (the workpiece is clamped) or move away from it (the workpiece is released).

The clamping force in power chucks is generated by a hydraulic or pneumatic cylinder located at the rear end of the spindle. Through the central hole of the spindle, the cylinder is connected by a rod to the chuck mechanism, which moves the cams that clamp the installed workpiece into the chuck.

Compressed air or liquid enters the rotating cylinder during processing using special device called a coupling. As a rule, the movement of the cams from a mechanized drive reaches 5-10 millimeters, so the design of the lathe chuck in any case allows you to quickly readjust the product when moving from processing between batches of workpieces.

To increase the accuracy of workpiece fastening when performing finishing machining, it is customary to use overhead non-hardened jaws, which are bored on a machine to fit certain dimensions of the workpiece mounting bases. For this purpose, the main cams clamp a short mandrel to select gaps in all mates, and after that the working surfaces of the overhead cam are bored to the largest diameter of the base surface of the part.

The design of non-hardened jaws and their fastening using a dovetail interface allows the overhead jaws to be installed with an accuracy of 0.02 millimeters and to avoid their subsequent boring.
For quick changeover between workpiece sizes, universal non-hardened jaws are required; this is achieved by rotating the round or hexagonal heads of the overhead jaws, which are mounted on the main jaws and bored to a certain position. required diameter. Large-diameter workpieces are fixed in such a chuck with the cam stages placed in reverse.

If there is a need to process two similar surfaces, it is customary to use non-hardened cams, the error in fastening the workpieces in which can be reduced to 0.03-0.05 millimeters. Workpieces such as shafts that are longer can be installed in a lathe chuck, which has a rear center pressure.

DIY lathe chuck

You have become acquainted with the structure and main types of lathe chucks, and now we present to your attention a version of a homemade lathe chuck for a wood lathe. The main working part of the cartridge is the elastic sleeve, which has a diameter of 6 millimeters. It is necessary to use two types of bushings - polyurethane and rubber, for which you can take trimmings of sealing harnesses.

The union nut must be made of brass or bronze. Steel can also be used for this purpose, but bronze nuts have less friction. You can make the patch from any material, you can even take duralumin. The body is machined from steel. There must be an internal hole or thread in its shank - this depends on the design of the shaft shank of the device on which the cartridge is to be installed.

The rubber bushing and housing are the most critical parts in the cartridge. Whether the drill clamped in the chuck will “hit” depends on how accurately they are made. To reduce the likelihood of “beating” Make drills and both parts in a certain sequence. Machine the chuck body in one setup. This technique will ensure the alignment of the central hole and the bushing shank with a certain accuracy.

The chuck body will remain in the lathe spindle after machining. Insert the elastic sleeve blank inside the cartridge and lightly press it through the patch with the union nut. Insert a drill with a diameter of 1 millimeter into the tailstock of the machine and drill out the clamped bushing. Using this method, it is advisable to make several bushings in stock.

If you are unable to lock the shaft of the drilling device when clamping the drill, you need to make flats on the body of a homemade chuck for a lathe wrench so that you can union nut tighten tightly. In a lathe chuck you can clamp drills that have a diameter of 0.8 to 1.2 millimeters. For drills of a different diameter, the holes in the nut and bushing must be made differently.

The main difference between this chuck lies in the fact that the elastic sleeve will clamp the entire shank of the drill, and in order to install a standard drill in the Verbovoy chuck, it is recommended to cut off its shank. Make the hole for the elastic sleeve not in the nut, but in the chuck body; it should be as close as possible to the clamping device of the machine spindle. This significantly increases the accuracy of drill centering during installation.

Now you know what lathe chucks are for and what function they perform when working on a lathe. In addition, it is not at all difficult to make a lathe chuck with your own hands. To do this, you must first of all decide on the environment in which the product will be used and strictly follow our instructions.

Articles on the topic

DIY lathe chuck

Even today, lathes play a huge role in the production of certain parts. All components and all equipment on any machines change over time, as they are subject to wear.

All these elements of equipment must be of high quality and durable, since the quality of the finished product depends entirely on the quality of the installed parts. So is the lathe chuck. It is without this element that the machine becomes useless. Below we will analyze everything related to this element of the lathe. Let's start by finding out what this part is.

General concepts

The chuck is one of the main elements of turning equipment. It is due to this that the future workpiece is fastened (installed). It is attached to the headstock with the gearbox. The chuck mechanism consists of a cam device.

It is the cams, under the influence of mechanical force, that tightly fix various workpieces having different diameters and sizes. Due to its massiveness and tight fastening on the machine, the chuck carries out accurate movement of the workpiece and does not allow the workpiece to move during operation, and also does not allow deformation. The chuck also rotates the workpiece, which makes processing easy.

Purpose

It is this part of the machine that has the most important mission in any workpiece processing. Due to the cam mechanism, which is located inside the chuck itself, the workpiece is clamped and centered. This happens due to the simultaneous narrowing of the cams around the plane of the workpiece. After clamping the workpiece, the workpiece is clamped with a quill located on the tailstock. When these actions are completed, the machine starts and the part rotates, which can be processed.

Tip: You need to know that before starting the equipment, after replacing the lathe chuck, you should set the rotation speed to low. This is done in order to check the values ​​of the axial and radial runout of the jaw chuck operating at idle speed.

Variety

Nowadays, lathe chucks are distinguished by the presence of fastening elements (jams). There are only three of these types:

Double cam

Such cartridges are capable of securing complex, asymmetrical and shaped parts. In such cartridges it is possible to secure surfaces that are not subject to treatment. They are used when small production, as well as in serial.

Three cam

This type of equipment is the most common and is used in all work. Allows you to process round and hexagonal parts. This type of chuck uses three different jaws. Regardless of this, the workpiece is centered together with the clamping of all three cams.

Four cam

This type is used for processing rectangular workpieces. Here, for each cam, there is a separate mechanical unit, which makes all cams independent.

Types of jaw chucks

But the types of cartridges do not end with three types. They are also divided according to the mechanism for fixing the workpiece:

They consist of a sleeve with slots in which the petals are located (various modifications include from 3 to 6 petals). These petals act as cams.

This type of equipment is used mainly on machines with numerical control. Fastening workpieces are produced using 3 cams, which are located on a flat spindle.

These cartridges contain sliders, with the help of which the cams move by lever force. This type is used for small-scale production, as well as for processing a single workpiece.

Membrane view

In this case, a pneumatic drive is used, with the help of which the membrane is compressed. This type is used only for fine processing, to remove a thin layer of chips.

Drilling

Such cartridges are similar in principle to cartridges for hand drills. When the nut is tightened with a special wrench, the cams are smoothly squeezed out. Due to this action, the part or tool is clamped.

Thermal cartridge

This type of device is very inconvenient to use. This is due to the fact that when attaching the workpiece, thermal heating of the chuck itself is performed, and the same actions are performed when removing the tool.

Hydraulic chuck

The principle of operation is similar to that of a thermal cartridge. The part is clamped by a liquid that compresses the cams under pressure. Due to the liquid contents in the cartridge, additional damping of vibrations that occur during operation is performed.

Tip: Before choosing a lathe chuck woodworking or for metal. it is necessary to decide on the type of processing, material and molding of parts. You should also remember that get additional accessories to the cartridge will not be superfluous.

Design

Design of jaw lathe chuck

Let's look at the structural elements that make up the lathe chuck itself:

Used to carry out clamping actions.

Allows you to use the key to perform certain actions to clamp the part and vice versa.

Produces free passage of the key.

Prevents the part from unscrewing while the machine is running.

Transmits rotational motion to the spiral disk.

The part on which the entire structure is fixed.

Spiral disc

Due to the rotational movement of the gear, this disk drives the cams.

Reverse cam

Used for clamping the workpiece from the inside.

Cam straight

Used for clamping the workpiece from the outside.

An element of a part on which the cam mechanism is located.

Overhead cams

For clamping long and short parts with large diameters.

Each of the parts of the entire mechanism performs a specific function and is not superfluous.

Assembly according to drawings

Drawing of a three-jaw chuck

The jaw chuck for turning equipment is assembled according to diagrams that can be downloaded from the Internet and printed on a printer. As a rule, factory cartridges cost big money and therefore many have learned do such details homemade. Their design is simple, but quite understandable. Before you begin assembling this fixture, you must fully understand the entire mechanism of the chuck and cam mechanism. If it is not possible to make such elements yourself, then they can be ordered from any turner. It won't cost much.

Assembly begins with a flange on which all the necessary holes for fastenings are located. Following this, all the parts of the mechanism are gradually installed, which are completed by covering the body and bolting everything cartridge

Installing the jaw chuck

Installation is carried out as follows and in strict sequence:

Installation of the mandrel

First of all, this part is installed to ensure complete fitting of the cartridge.

Installing the chuck itself on the spindle

Using a frame, it is put on the spindle and secured with bolts.

Consolidation

Attached cartridge onto the spindle with bolts. In this case a good helper there will be a simple open-end wrench.

Securing the workpiece

After installing the chuck, a part, workpiece or tool is fixed into it.

Releasing the cartridge

After all work, the mandrel is removed.

Tip: After replacing the jaw chuck, you need to check the operation of the machine. The axial runout and taper of the seat should not exceed a value of three microns.

It is important to know! This device must be subject to frequent disassembly to lubricate and clean the cam mechanism! If the cartridge is in a removable state, then it must be prepared for storage. To do this, the cams are brought to the center, this ensures the safety of centering, and the hole in the center must be plugged with a clean rag or other material. This will prevent dust from getting onto the walls of the hole.

Video reviews

Video review of installation on the machine:

Video review, disassembly, cleaning, polishing:

Video review of a wood lathe chuck:

Video review of a homemade lathe chuck made of wood ( cheap option):

  • Members
  • 2386 messages
    • City: Crimea, Simferopol
    • Name: Yuri

    My homemade, small homemade lathe.

    If possible, I'll post the drawings tomorrow.
    Some details about the design:
    The guides are the rods of the front shock absorber struts of the VAZ 2109 with a diameter of 22 mm, on the thin thread side they are cut and machined for a standard M14 x 1.5 thread, on the other side it is already there.
    I had to order the spindle housing, axle and rear support for the guides. The holes for the guides and the spindle axis were made from one setting on the coordinate, the accuracy depends on this. During assembly, I used brass foil gaskets to install the guides. The following measurements revealed that the accuracy of installation of the guides along the spindle axis at the rear support was 0.02 mm horizontally and 0.05 mm vertically. More than ok for my purposes.
    For the caliper I used a blank with a hole for the bushings for the front guide. The blank and bushings are cut and tightened with screws to adjust the play. In the rear there is a milled step whose caliper rests through a brass gasket on the rear guide. It is pressed from below with a 3mm plate. A single-axis table from some kind of optical device is screwed onto the support from above. I turned an M6 lead screw, a brass nut and two stops for it almost by hand. A 5 mm plate and a tool holder are screwed onto the top of the table. The longitudinal lead screw is made from a standard M12 stud, they are sold on construction sites, and is fixed in brass bushings on the spindle body and rear support.
    The tailstock is made from a piece of 70 mm angle, a 12 mm plate in which a triangular groove is milled for the front guide, and a step for the rear, as well as a piece of 20 mm rod. All this was cooked by eye, but preferably more precisely. Then the headstock is installed in its place. The lower pressure on the headstock is adjusted so that it moves along the guides with a sufficiently large force. A small-diameter drill is clamped into the spindle chuck (I started with 4 mm) and, moving the headstock to the spindle, little by little, a longitudinal hole is carefully drilled in it. Then the drill is 0.5 mm larger and also repeated. And so on up to a diameter of 6.7 mm. Decent alignment is guaranteed. Then, an M8 tap is used in the chuck and a thread is cut into the tailstock by turning the chuck with a knob.
    Basically, that's all in a nutshell. I will be glad if it is useful to someone.
    I don’t have a rotating center in the tailstock; when necessary, I use a hardened stationary center, which is inserted instead of a drill into collet tailstock chick.

    #9 Admin Guest_Dmitry_* 05 May 2006 — 13:10

    My homemade, small homemade lathe.

    Super!!
    If it's not difficult, send the drawings to

  • Members
  • 2386 messages
    • City: Crimea, Simferopol
    • Name: Yuri

    My homemade, small homemade lathe.

    Attached images

    #11 Sergey I

    • City: MO Village

    My homemade, small homemade lathe.

    Yuri Kimborovich said:

    The main limitation is that a workpiece diameter of 13mm will not fit into the chuck.

    You can put a 16 mm cartridge, it won’t be much, but it will add more possibilities.

    In general, you got a THING.

    Sincerely,
    Sergey

  • Members
  • 2386 messages
    • City: Crimea, Simferopol
    • Name: Yuri

    My homemade, small homemade lathe.

    thank you for rating!
    On sketches general view Dimensions are not indicated, but the scale is 1x1.

    Attached images

  • Members
  • 2386 messages
    • City: Crimea, Simferopol
    • Name: Yuri

    My homemade, small homemade lathe.

    Yesterday they gave me a higher class camera to use.
    The photos turned out best quality, and tried to remove it so that the entire structure was visible.

    Attached images

  • Administrator
  • 20992 messages
    • Name: Alexey

    My homemade, small homemade lathe.

    I saw lathe chucks with a diameter of 80 mm on the market. Will this not fit on your machine?

  • 3679 messages
    • Moscow city

    My homemade, small homemade lathe.

    Yes, the difference between the pictures is quite impressive. There was a feeling not of a self-made product from whatever it would turn out, but of a planned machine.
    If it's not a secret, what program do you draw in? Are the drawings really made before the machine? or transferred to the finishing version after the machine has been manufactured. I wouldn’t have the patience to draw finishing options, knurling, chamfering, if they are not structurally necessary.

  • Members
  • 2386 messages
    • City: Crimea, Simferopol
    • Name: Yuri

    My homemade, small homemade lathe.

    As for the cartridge, the 80 is too big and heavy for it. Once upon a time, the Soviet industry for watchmaking machines produced a 60 mm lathe chuck and it was designated C92. I saw one like this on a watch lathe, but I couldn’t find such a rarity.
    The drawings were made before the manufacture of the machine in a fairly simple vector editor Xara X. I just once had to work a lot in it and I work in it quite quickly. I had to design it in such a way that it would be clear to those to whom I ordered the parts. And the sketches were reworked 15 times in the editor in search of simplifying the design before moving on to the metal. You can see for yourself what happened.
    Basically, he is a hard worker for me. I just bought a large machine and am now repairing it, but all the little things have been sharpening for a year now. Yesterday, by the way, for the gearbox of a large machine, I turned a dozen M6 x 8 locking screws on it.
    If you have questions about the design, ask, I will be happy to answer.

    Any equipment works efficiently and its performance is at a high level if its equipment is in order. In production, the speed, accuracy and reliability of securing the workpiece on CNC machines and devices that operate as part of the GPS are of great importance. To reduce the time it takes to position the workpiece on the unit, as well as to increase the reliability and accuracy of its fixation, chucks for wood lathes are used.

    Features of the lathe chuck

    The wood lathe chuck is an integral part of the wood turning equipment complex. This design detail is used for fastening piece workpieces and bar material on lathes, screw-cutting lathes, turrets, grinders, and metalworking equipment. Thanks to the lathe chuck, you can clamp workpieces of various sizes. The workpieces are fixed by inner part its holes, the surface on the outside or the outer surface for the shaft.

    The chucks of lathes, which have mechanized drives, reduce the time required to fix the workpiece on the equipment, as well as its removal after the processing process, this helps to increase labor productivity. Moreover, these products increase processing accuracy by ensuring the coordination of workpieces relative to the working parts of the lathe, as well as the reliability of fastening, eliminating deformation or displacement during operation.

    The most famous European manufacturers of wood lathe chucks are German company Rohm and the Polish company Bison-bial. These products are also produced by domestic factories producing technical equipment, machine components and tools. These products have a high price, but today there is simply no alternative to using lathe chucks in production.

    Principle of operation

    The chuck of a wood cutting machine is used in closed environments where there are no aggressive substances that cause corrosion. Before starting work, tighten the coupling bolts to the maximum using a wrench. After this, the lathe chuck is mounted on the machine, all the bolts are tightened with nuts and the lathe unit is started. You should first set the speed to low to check the values ​​of the axial and radial runout of the device at idle.

    In order to secure the workpiece on machines, two-jaw and three-jaw chucks are used, rarely four-jaw chucks. The lathe part for fixing and holding parts is equipped with cams, their number is 2-6 pieces.

    In this case, the products can be with independent movement of the cams and with their fastening to the flanged end of the spindle. Depending on the method of fixing the lathe chuck to the machine, the following types of fastening are classified:

    • using an adapter flange,
    • to the flanged end of the spindle,
    • onto the lathe spindle itself.

    By simultaneously moving the clamping jaws in the radial direction, centering of the workpiece in the chucks is achieved. The cams move thanks to a disk, which on one side is equipped with grooves in the form of an Archimedean spiral, and on the other there is a bevel gear that interacts with three others. Using the key, one wheel begins to move, and at the same time the disk rotates, moving all the cams evenly. The direction of rotation of the disk determines whether the jaws approach the center of the chuck, while the workpiece is clamped, or move away from it (release of the part).

    In mechanical chucks, the clamping force depends on a hydraulic or pneumatic cylinder located at the rear end of the spindle. The cylinder is connected by means of a rod to the chuck mechanism, which moves the cams that clamp the workpiece through the spindle hole in its central part.

    During the processing process, compressed air or liquid enters the rotating cylinder using a special device called a coupling. Typically, the movement of the cams from the drive, which is mechanized, approaches a value of 5-10 mm. Because of this, the design of the lathe element allows you to quickly reinstall the product during the transition between batches of workpieces in the processing process.

    During finishing processing on a machine, in order to secure the workpiece extremely precisely, overhead non-hardened jaws are used, which are sharpened on the machine to the required dimensions of the workpiece mounting bases. To do this, the main jaws are used as a short mandrel clamp to select clearances in all interactions, then the operating surfaces of the overhead jaw are bored to a larger diameter of the base surface of the part.

    Thanks to the dovetail coupling, the design of the non-hardened jaws and their fixation allows the installation of overhead jaws with an accuracy of 002 mm and bypasses their subsequent boring.

    To quickly change workpiece sizes, non-hardened cams are required. This can be achieved by turning the round or hexagonal shaped heads of the overhead cams, mounted on the main cams and bored to a certain diameter, into the desired position.

    If there is a need to process two identical surfaces on a machine, then non-hardened cams are used; if the error in fastening the workpieces in them can be reduced to 0.03 -0.05 mm. Workpieces with longer lengths such as shafts are installed in a lathe chuck that has a rear center clamp.

    Chucks 3 x jaw 250 mm

    Lathe elements 3 x cam 250 mm self-centering manual control designed for fixing piece workpieces that need to be processed, as well as for securing bar material on turning equipment. This product is certified.

    User manual

    Before installation, it is necessary to lubricate the rubbing surfaces; it must contain molybdenum disulfide. The accuracy of the 3 jaw 250 mm chuck is guaranteed if the following requirements are met:

    • This product needs to be serviced once a month by disassembling, cleaning and lubricating.
    • The rubbing surfaces of the 3-jaw 250 mm chuck should be degreased and lubricated.
    • When installing the jaws, you need to ensure that their numbers correspond to the numbers of the grooves in the chuck body.

    So, you have become familiar with lathe chucks, you know what they are needed for and what function they perform when working on the machine.

    • Print

    stanok.guru

    DIY lathe chuck

    Even today, lathes play a huge role in the production of certain parts. All components and all equipment on any machines change over time, as they are subject to wear.

    All these elements of equipment must be of high quality and durable, since the quality of the finished product depends entirely on the quality of the installed parts. So is the lathe chuck. It is without this element that the machine becomes useless. Below we will analyze everything related to this element of the lathe. Let's start by finding out what this part is.

    General concepts

    The chuck is one of the main elements of turning equipment. It is due to this that the future workpiece is fastened (installed). It is attached to the headstock with the gearbox. The chuck mechanism consists of a cam device.

    It is the cams, under the influence of mechanical force, that tightly fix various workpieces having different diameters and sizes. Due to its massiveness and tight fastening on the machine, the chuck carries out accurate movement of the workpiece and does not allow the workpiece to move during operation, and also does not allow deformation. The chuck also rotates the workpiece, which makes processing easy.

    Purpose

    It is this part of the machine that has the most important mission in any workpiece processing. Due to the cam mechanism, which is located inside the chuck itself, the workpiece is clamped and centered. This happens due to the simultaneous narrowing of the cams around the plane of the workpiece. After clamping the workpiece, the workpiece is clamped with a quill located on the tailstock. When these actions are completed, the machine starts and the part rotates, which can be processed.

    Tip: You need to know that before starting the equipment, after replacing the lathe chuck, you should set the rotation speed to low. This is done in order to check the values ​​of the axial and radial runout of the jaw chuck operating at idle speed.

    Variety

    Nowadays, lathe chucks are distinguished by the presence of fastening elements (jams). There are only three of these types:

    Double cam

    Such cartridges are capable of securing complex, asymmetrical and shaped parts. In such cartridges it is possible to secure surfaces that are not subject to treatment. They are used in small production, as well as in serial production.

    Three cam

    This type of equipment is the most common and is used in all work. Allows you to process round and hexagonal parts. This type of chuck uses three different jaws. Regardless of this, the workpiece is centered together with the clamping of all three cams.

    Four cam

    This type is used for processing rectangular workpieces. Here, for each cam, there is a separate mechanical unit, which makes all cams independent.


    Types of jaw chucks

    But the types of cartridges do not end with three types. They are also divided according to the mechanism for fixing the workpiece:

    Collet

    They consist of a sleeve with slots in which the petals are located (various modifications include from 3 to 6 petals). These petals act as cams.

    Wedge

    This type of equipment is used mainly on machines with numerical control. The workpiece is secured using 3 cams, which are located on a flat spindle.

    Lever

    These cartridges contain sliders, with the help of which the cams move by lever force. This type is used for small-scale production, as well as for processing a single workpiece.

    Membrane view

    In this case, a pneumatic drive is used, with the help of which the membrane is compressed. This type is used only for fine processing, to remove a thin layer of chips.

    Drilling

    These chucks are similar in principle to chucks for hand drills. When the nut is tightened with a special wrench, the cams are smoothly squeezed out. Due to this action, the part or tool is clamped.

    Thermal cartridge

    This type of device is very inconvenient to use. This is due to the fact that when attaching the workpiece, thermal heating of the chuck itself is performed, and the same actions are performed when removing the tool.

    Hydraulic chuck

    The principle of operation is similar to that of a thermal cartridge. The part is clamped by a liquid that compresses the cams under pressure. Due to the liquid contents in the cartridge, additional damping of vibrations that occur during operation is performed.

    Tip: Before choosing a lathe chuck for wood or metal, you need to decide on the type of processing, material and molding of the parts. You should also remember that it will not be superfluous to acquire additional accessories for the cartridge.

    Design

    Design of jaw lathe chuck

    Let's look at the structural elements that make up the lathe chuck itself:

    Key

    Used to carry out clamping actions.

    Spring

    Allows you to use the key to perform certain actions to clamp the part and vice versa.

    Sleeve

    Produces free passage of the key.

    Stopper

    Prevents the part from unscrewing while the machine is running.

    Gear

    Transmits rotational motion to the spiral disk.

    Flange

    The part on which the entire structure is fixed.

    Spiral disc

    Due to the rotational movement of the gear, this disk drives the cams.

    Reverse cam

    Used for clamping the workpiece from the inside.

    Cam straight

    Used for clamping the workpiece from the outside.

    Frame

    An element of a part on which the cam mechanism is located.

    Overhead cams

    For clamping long and short parts with large diameters.

    Each of the parts of the entire mechanism performs a specific function and is not superfluous.

    Assembly according to drawings

    Drawing of a three-jaw chuck

    The jaw chuck for turning equipment is assembled according to diagrams that can be downloaded from the Internet and printed on a printer. As a rule, factory cartridges cost a lot of money and therefore many have learned to make such parts homemade. Their design is simple, but quite understandable. Before you begin assembling this fixture, you must fully understand the entire mechanism of the chuck and cam mechanism. If it is not possible to make such elements yourself, then they can be ordered from any turner. It won't cost much.

    Assembly begins with a flange on which all the necessary holes for fastenings are located. Following this, all the parts of the mechanism are gradually installed, which are completed by covering with the case and bolting the entire cartridge

    Installation

    Installing the jaw chuck

    Installation is carried out as follows and in strict sequence:

    Installation of the mandrel

    First of all, this part is installed to ensure complete fitting of the cartridge.

    Installing the chuck itself on the spindle

    Using a frame, it is put on the spindle and secured with bolts.

    Consolidation

    The chuck is secured to the spindle with bolts. In this case, a simple open-end wrench will be a good helper.

    Securing the workpiece

    After installing the chuck, a part, workpiece or tool is fixed into it.

    Releasing the cartridge

    After all work, the mandrel is removed.

    Tip: After replacing the jaw chuck, you need to check the operation of the machine. The axial runout and taper of the seat should not exceed a value of three microns.

    It is important to know! This device must be disassembled frequently to lubricate and clean the cam mechanism! If the cartridge is in a removable state, then it must be prepared for storage. To do this, the cams are brought to the center, this ensures the safety of centering, and the hole in the center must be plugged with a clean rag or other material. This will prevent dust from getting onto the walls of the hole.

    Video reviews

    Video review of installation on the machine:

    Video review, disassembly, cleaning, polishing:

    Video review of a wood lathe chuck:

    Video review of a homemade lathe chuck made of wood (cheap option):

    stanki-info.ru

    DIY lathe chuck | Construction portal

    The quality and performance of any equipment depends directly on the condition of its equipment. It is especially important to accurately, quickly and reliably secure workpieces on CNC machines and machines that operate as part of the GPS. To reduce the time required to position the workpiece on the machine, as well as to increase the reliability and accuracy of its fastening, chucks for lathes are widely used.

    Features of the lathe chuck

    A lathe chuck is an integral part of the equipment complex when carrying out turning operations. This structural part is intended for securing piece workpieces and bar material on screw-cutting lathes, grinders, turret and lathes, as well as metalworking equipment. With a lathe chuck you can clamp workpieces of a wide variety of sizes. The workpieces are attached to the inner plane of its hole, the outer surface or the outer surface for the shaft.

    Lathe chucks with mechanized drives make it possible to reduce the auxiliary time required to install a workpiece on equipment and remove it after processing, thereby increasing labor productivity. On the other hand, these products increase processing accuracy, as they ensure coordination of workpieces relative to the working parts of the lathe and their reliable fastening, which eliminates deformation or displacement during processing.

    Some of the world's most famous manufacturers of wood lathe chucks in Europe are Rohm (Germany), Bison-bial (Poland), as well as some domestic factories of technical equipment, tools and machine components. These products are quite expensive, but today it is simply impossible to imagine production without the use of lathe chucks.

    Operating principle of lathe chuck

    The lathe chuck should be used indoors and in the absence of aggressive substances that cause corrosion. Before starting work, the tightening bolts are tightened to the maximum with a wrench, then the lathe chuck is secured on the machine, all bolts are tightened with nuts and the lathe is started. It should be taken into account that low speeds are set to begin with to check the values ​​of the end and radial runout of the lathe chuck at idle speed.

    For fastening products on lathes, two- and three-jaw chucks are widely used, less often - four-jaw chucks. To fasten and hold parts, the lathe chuck contains cams, the number of which varies from 2 to 6. In this case, lathe chucks come with independent movement of the cams and with direct attachment of the cams to the flange end of the spindle. Depending on the method of fastening the lathe chuck to the machine, the following types of fastening are distinguished: on the flanged end of the spindle, through the adapter flange, directly on the lathe spindle itself.

    Centering the workpiece in the chucks is achieved by simultaneously moving the clamping jaws in the radial direction. The cams of the lathe chuck move simultaneously with the help of a disk, which has grooves in the form of an Archimedean spiral on one side and a bevel gear, which is associated with three others, on the other. The key sets one wheel in motion, at the same time the disk also turns and moves all the cams evenly. The direction of rotation of the disk will determine whether the jaws approach the center of the chuck (the workpiece is clamped) or move away from it (the workpiece is released).

    The clamping force in power chucks is generated by a hydraulic or pneumatic cylinder located at the rear end of the spindle. Through the central hole of the spindle, the cylinder is connected by a rod to the chuck mechanism, which moves the cams that clamp the installed workpiece into the chuck.

    During processing, compressed air or liquid enters the rotating cylinder using a special device called a coupling. As a rule, the movement of the cams from a mechanized drive reaches 5-10 millimeters, so the design of the lathe chuck in any case allows you to quickly readjust the product when moving from processing between batches of workpieces.

    To increase the accuracy of workpiece fastening when performing finishing machining, it is customary to use overhead non-hardened jaws, which are bored on a machine to fit certain dimensions of the workpiece mounting bases. For this purpose, the main cams clamp a short mandrel to select gaps in all mates, and after that the working surfaces of the overhead cam are bored to the largest diameter of the base surface of the part.

    The design of non-hardened jaws and their fastening using a dovetail interface allows the overhead jaws to be installed with an accuracy of 0.02 millimeters and to avoid their subsequent boring. For quick changeover between workpiece sizes, universal non-hardened jaws are required; this is achieved by rotating the round or hexagonal heads of the overhead jaws, which are mounted on the main jaws and bored to the desired diameter, into a certain position. Large-diameter workpieces are fixed in such a chuck with the cam stages placed in reverse.

    If there is a need to process two similar surfaces, it is customary to use non-hardened cams, the error in fastening the workpieces in which can be reduced to 0.03-0.05 millimeters. Workpieces such as shafts that are longer can be installed in a lathe chuck, which has a rear center pressure.

    DIY lathe chuck

    You have become acquainted with the structure and main types of lathe chucks, and now we present to your attention a version of a homemade lathe chuck for a wood lathe. The main working part of the cartridge is the elastic sleeve, which has a diameter of 6 millimeters. It is necessary to use two types of bushings - polyurethane and rubber, for which you can take trimmings of sealing harnesses.

    The union nut must be made of brass or bronze. Steel can also be used for this purpose, but bronze nuts have less friction. You can make the patch from any material, you can even take duralumin. The body is machined from steel. There must be an internal hole or thread in its shank - this depends on the design of the shaft shank of the device on which the cartridge is to be installed.

    The rubber bushing and housing are the most critical parts in the cartridge. Whether the drill clamped in the chuck will “hit” depends on how accurately they are made. To reduce the likelihood of drill “beating,” make both parts in a certain sequence. Machine the chuck body in one setup. This technique will ensure the alignment of the central hole and the bushing shank with a certain accuracy.

    The chuck body will remain in the lathe spindle after machining. Insert the elastic sleeve blank inside the cartridge and lightly press it through the patch with the union nut. Insert a drill with a diameter of 1 millimeter into the tailstock of the machine and drill out the clamped bushing. Using this method, it is advisable to make several bushings in stock.

    If you are unable to stop the shaft of the drilling device when clamping the drill, you need to make flats for a wrench on the body of a homemade chuck for a lathe so that you can tighten the union nut tightly. In a lathe chuck you can clamp drills that have a diameter of 0.8 to 1.2 millimeters. For drills of a different diameter, the holes in the nut and bushing must be made differently.

    The main difference between this chuck lies in the fact that the elastic sleeve will clamp the entire shank of the drill, and in order to install a standard drill in the Verbovoy chuck, it is recommended to cut off its shank. Make the hole for the elastic sleeve not in the nut, but in the chuck body; it should be as close as possible to the clamping device of the machine spindle. This significantly increases the accuracy of drill centering during installation.

    Now you know what lathe chucks are for and what function they perform when working on a lathe. In addition, it is not at all difficult to make a lathe chuck with your own hands. To do this, you must first of all decide on the environment in which the product will be used and strictly follow our instructions.

    Turning is a specific branch of woodworking; its difference lies in working with a rotating workpiece driven by the engine of a lathe. The craftsman feeds the cutting tool (cutter, milling cutter) with his own hands or by means of a mechanical drive. To securely fix the workpiece and transmit torque to it, various devices and lathe chucks are used, the diversity of which is due to the large number of turning techniques. Some of them can be made with your own hands without special equipment.

    Thrust centers

    Turning centers are divided into driven (geared) and thrust. The first ones are installed in the headstock of the machine and directly transmit force; for better adhesion to wood, they have several teeth. The second ones are placed in the tailstock and support the part; according to their design, they can be rotating or stationary. As a rule, centers have a Morse tapered shank.

    Faceplates

    A faceplate is a round metal plate with holes for fastening with self-tapping screws, mounted on the machine shaft using threads or bolts. They differ in diameter, presence or absence of teeth and additional fasteners. Used for turning plates, bowls and other similar products. Often made by hand. Working with the faceplate is thought out so that part of the wood into which the screws are screwed is subsequently removed.

    Jaw chucks

    The most convenient and functional. They work both in compression and expansion, so they can grip the workpiece both from the outside and from the inside. They differ in the number of cams and their drive mechanism.
    Unlike metalworking, two- and three-jaw chucks are practically not used for turning wood. Options with a spiral drive and non-removable cams are also not popular.
    The most common type of lathe chuck for woodworking is self-centering four-jaw, with a rack-and-pinion transmission mechanism and replaceable jaws.
    They are supplied to the Russian market by the brands Axminster, Jet, Barracuda and other, less well-known companies.

    Making a lathe chuck for wood with your own hands

    The manufacture of jaw chucks requires high-precision industrial equipment and it is hardly possible to make them in a home workshop. However, there are simpler designs that are not difficult to build with your own hands.

    Homemade wood turning faceplate with adjustable clamps

    You will need a flat sheet of steel with a thickness of at least 10 mm, a steel angle 50x50 mm, eight M8x30 bolts with nuts and washers. You should think in advance about how the device will be mounted on the machine and, if necessary, make or purchase an appropriate threaded bushing. After this you can proceed:

    1. Mark on the existing plate a circle of the required diameter and two axes passing through the center and intersecting at right angles.
    2. Cut out the faceplate blank using a jigsaw according to the markings and sand it thoroughly.
    3. Cut through grooves along the resulting axes, stepping back a few centimeters from the center and not reaching 2 - 3 cm to the edges. This can be done easier by pre-drilling holes slightly larger in diameter than the stocked bolts.
    4. Saw off four identical sections from the corner and drill one of the shelves of each with the same drill.
    5. In the second shelf of the corners, cut an M8 thread and screw in the bolts.
    6. Weld or solder a threaded bushing for mounting on the shaft.
    7. Screw the corners to the faceplate with bolts through washers.
    8. Attach the resulting wood chuck to the lathe.

    To fix this homemade cartridge the corners are moved to the desired position and secured by tightening the nuts; the part is finally tightened with bolts screwed into the threaded shelves.

    DIY vacuum chuck for wood

    If your lathe's headstock spindle has a through hole for knocking out the gear center, you can add a homemade vacuum chuck to your arsenal. For this you will need:

    • Powerful vacuum cleaner
    • Bearing closed type, approximately equal in outer diameter to a vacuum cleaner hose
    • A piece of thick rubber hose for connecting the vacuum cleaner and the bearing
    • Clamp
    • Standard faceplate with hole in the center
    • A small piece of MDF or thick plywood
    • Textolite for adapter

    A sleeve is machined from PCB, one side of which should be equal in diameter internal size bearing, the other - spindle. This homemade adapter is pressed into the bearing using glue; it will be held in the machine due to the tightness of the fit. The resulting structure is connected with a piece of hose to the vacuum cleaner and secured with a clamp.

    A disk is cut out of MDF or plywood, attached to a faceplate and ground. It is better to make the surface slightly concave. To ensure a tight fit, linoleum or thin rubber is glued on top.
    The disk is drilled through the center to remove air.
    A similar self-made chuck provides a pressing force of 40 - 50 kg, sufficient to hold medium-sized parts during finishing.

    The accuracy and quality of processing largely depends on the installed chuck. The chuck secures a workpiece of piece or rod type and transmits the main cutting movement.

    Processing with high speeds cutting requires high centering accuracy from the chuck and reliable fastening of the workpiece.

    Variety

    The cartridges differ in design depending on their functional and technological purpose.

    Lathe chucks are classified according to several criteria:

    • Method of attachment to the machine: on the spindle flange, using an adapter flange, directly on the machine spindle.
    • Jaw installation: independent movement, mounted directly on the spindle flange.
    • Principle of workpiece securing: manual, mechanized (with hydraulic or pneumatic drive).

    The principle of manual workpiece clamping

    The use of a mechanized drive reduces the amount of auxiliary time spent on installing and securing the workpiece. The drive ensures precise positioning of the workpiece and centering during installation; this mechanism helps to increase processing accuracy.

    Lathe chucks have different numbers of jaws. They can be 2, 3 and 4 cam. The cams are in direct contact with the workpiece during operation and hold it in one position. There are direct and reverse.

    The tree (blank) is fixed by the outer surface or hole for parts in the form of bodies of revolution; prismatic parts are attached to the outer edges.

    The cartridge is a complex technological product of a prefabricated design. Various materials are used in the manufacture of assembly units. The body is made of gray cast iron grade SCh 30. The material for the parts is tool steel with high tensile strength and heat treatment. Roughness on working surfaces is not higher than 1.6.

    Classification

    Depending on the design lathe chucks are:

    • lever;
    • self-centering;
    • wedge;
    • collet;
    • membrane





    Lever view

    Perhaps the most popular design. The action of the mechanism is based on the movement of cams and clamps due to the mobility of a two-arm lever. The presence of a hydraulic drive allows you to optimize the design.

    The main characteristics of the device include the number of clamps for securing the cam and the ability to move along the working disk. Setting up such a cartridge is quite difficult, especially with non-standard processing.

    Changeover occurs according to two schemes:

    • Independent adjustment of the cams is a labor-intensive operation and is not performed for every structural type cartridge.
    • Synchronous movement of cams with a key.

    To carry out adjustment, a special key is installed in the groove for adjusting the hydraulic drive.

    When working with a device of this type, there is a slight play of the part when rotating. For this reason, lever designs are more often used in roughing.

    Self-centering view

    The workpiece is centered in the chuck due to the simultaneous movement of the jaws, which is typical for a three-jaw self-centering chuck. Synchronous movement of all cams is ensured by the rotation of the disk, at the end of which grooves are made in an Archimedes spiral.

    A bevel gear is cut on the opposite side of the disk. It engages with three small tips. When the key is turned, a small geared bevel gear meshes with the disk is rotated.

    The disk begins to rotate and moves the cams inserted into the grooves of the spiral. Changing the direction of rotation brings the cams together or apart from the center. The bringing together or spreading of the cams is accompanied by clamping or squeezing the workpiece.

    In power-driven chucks, the clamping force is provided by a hydraulic cylinder or pneumatic cylinder mounted on the rear side of the spindle. The cylinder rod is connected by means of a rod to the mechanism for moving the cams in the chuck. The rod passes through the central hole in the spindle. Moving the piston to one side or the other means that the workpiece is clamped or released.

    Wedge view

    The wedge design appeared after the improvement of the lever chuck.

    The accuracy of movement of each cam was ensured after installing separate mechanical or pneumatic drives, which made it possible to use the device for precise operations.

    The wedge chuck has an undeniable advantage over other designs. It has the function of shifting the workpiece axis from the central axis of the machine. The presence of eccentricity expands the machine’s capabilities for processing parts of complex configurations.

    Characteristic features when working with wedge chucks:

    • Difficulties in setting up for surgery.
    • High installation accuracy with a low percentage of error.
    • The evenly distributed load from the clamping force by each jaw increases the reliability of securing the workpiece.

    A lathe with a CNC device needs quick readjustment. In such machines, clamping modules are installed with the ability to connect to a control system.

    The material from which wedge chucks are made must meet high quality standards. The performance characteristics of the chuck must not be allowed to change during high speed machining.

    Collet type

    A collet chuck will help you quickly and reliably fasten a cylindrical part on a lathe. During the first installation, difficulties may arise; a specialist should study the instructions, as well as the technical data sheet of the product.

    The collet, which is the main structural element, is a bushing with longitudinal axial slots. Due to the slots, elastic clamping petals are formed. They serve as cams when clamping the workpiece. Their number varies from 3 to 6 in accordance with the diameter of the sleeve. The collet is placed in a housing with a clamping nut.

    The workpiece installed in the sleeve is evenly compressed by the petals due to the pressure of the nut on the cone, which creates a compressive force. The workpiece receives rigid fixation, and there is almost no radial runout.

    The collet-type chuck is designed for a long period of operation, and the number of fastenings and removals is not regulated. The master needs to develop a principle of operation of the machine, with the help of which the efficiency will be optimal. Modern units are easy to customize; many workshops offer installation services for such equipment.

    Membrane view

    Diaphragm type lathe chucks are characterized by high accuracy centering and securing the workpiece.

    A membrane made of elastic material is located on the flange of the mechanism. Clamping jaws with replaceable jaws are installed on it. The number of cams varies from 3 to 8.

    When securing the workpiece, the pneumatic drive is turned on.

    Under pressure, the membrane bends, the jaws diverge by 0.1–0.2 mm. The workpiece is inserted into the chuck until it stops and the drive is turned off. Under the action of elastic forces, the membrane tends to return to its original position. The jaws compress the workpiece.

    Such a process takes a small amount of time, but the master is required to be scrupulous, attentive and careful. The production process should not be taken lightly. Unit parts easily fail under pressure.

    The membrane, made of spring steel, firmly holds the workpiece during processing. As the number of cams increases, the centering accuracy increases.

    Membrane chucks are used for finishing operations with low cutting forces. The specifics of the work are not known to every master; it is necessary to study regulatory framework, as well as recommendations from professionals.

    How to choose a part

    The optimal chuck model for the machine is selected based on a comprehensive methodology. First of all, the technical data of the machine and the operations performed are taken into account. Based on this, the following parameters are analyzed.

    Working diameter – experts pay attention to the outer diameter of the device and the size available for installation on such equipment. The fit size of the groove and the location of the fasteners are important.

    Design - the method of securing the workpiece, the location and number of cams matters.

    Parameters of the workpieces - you need to know the maximum and minimum diameter along the shaft and hole of the future workpiece, weight, length, configuration. These factors influence the method of fastening - direct or reverse cams.

    The size of the hole in the hollow spindle for installing a rod workpiece. As well as the rotation speed range.

    The operating conditions of the lathe chuck require placement in a closed room, where the negative impact of natural factors and aggressive environments that can cause corrosion is excluded.

    The lathe chuck is an integral part of the lathe and without it mechanical restoration impossible.

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