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Metal parts are constantly needed to repair a car. Well, if the model is common, you can buy it. If the car is rare, you either have to wait a long time until they deliver it, or order production. In this case, you can purchase a lathe for the garage. If you have experience, you can use it for part-time work.
What types of lathes are suitable for private use
There are nine types of lathes in total, but not all are needed in the garage. Most often, private traders can see small screw-cutting lathes. Along with the processing of parts (grinding, drilling, milling, drilling of radial holes, etc.), they perform various types of threading and taper turning. It is such a lathe for the garage that they are trying to buy – it covers almost all the needs of car owners.
Are issued in two types — desktop and with a bed (floor). Desktop – small, with low weight (up to 200 kg) machines. It is easier for them to find a place in the garage. The disadvantage is that you cannot process large and heavy parts on them. Another point: due to their small mass, they are not always able to give out high processing accuracy.
Floor lathes (usually school ones) have a much larger mass and dimensions. For normal operation, a separate foundation must be made under them. Installation on vibration dampers is possible, but it is not easy to find them.
Lathe device
In order to choose a lathe, it is desirable to know its device, purpose, functions and possible parameters of each of the parts. First, let’s take a look at the main nodes.
- Base or bed. Preferably a heavy, cast iron stove. Even on desktop models. Very light machines will be unstable, making even acceptable accuracy difficult to achieve.
- Engine and gearbox. The engine can be powered by 220 V or 380 V. Gearbox – a device for ensuring the rotation of the spindle and caliper (on automatic and semi-automatic machines). The machine will last longer if the gears are made of metal (there are plastic ones).
- Front grandma. The main function is reliable fixation and rotation of the workpiece. Usually it is a massive metal cylinder, rigidly fixed in the body. Sometimes the headstock and gearbox are combined, in some models the headstock can move the caliper or processing head.
The device of a metal lathe - Rear grandma. This part is also necessary for reliable fixation of parts relative to the spindle. When processing small parts, it is rarely used, more often with long or massive ones. In some models, additional equipment can be attached to the tailstock – a cutter, drill, etc. – for the possibility of processing on both sides without changing the position of the part.
- Caliper. This is a whole node, on the device of which the list of operations performed by the machine depends. The support holds the cutting tool, shifting it when processing the part in several planes at once (the simplest ones – only in one plane). It can be controlled automatically or manually.
These are the main components of the lathe. It makes sense to take a closer look at complex nodes, since the capabilities and operation of the equipment depend on their execution.
Stanina
Most often, these are two parallel massive metal beams / walls, connected by crossbars to give greater rigidity. The caliper and tailstock move along the frame. For this purpose, guide sleds are machined on the frame. The tailstock moves along flat guides, the caliper – along prismatic ones. Very rare prism guides for the tailstock.
When choosing a used machine, pay attention to the condition of the slide and the smoothness of the movement of parts along them.
Front (spindle) grandma
The headstock in modern lathes, most often, combines a workpiece holder and a device for changing the spindle speed. There are several types of speed control – by moving the levers to a certain position, using the regulator.
The control of the regulator with a smooth change in the speed of rotation is carried out on the basis of microprocessor control. In this case, the headstock has a liquid crystal display on which the current speed is displayed.
The main part of the headstock is a spindle, which on one side is connected to the electric drive pulley, on the other side it has a thread onto which the cartridges holding the workpiece are screwed. The accuracy of turning operations directly depends on the condition of the spindle. There should be no beats and backlashes in this knot.
In the headstock there is a system of interchangeable gears for transmitting and changing rotation to the gearbox shaft. When choosing a garage lathe, pay attention to the condition of the gears and the absence of spindle play. This affects the accuracy of workpiece processing.
tailstock
The tailstock is movable – it moves along the guides on the frame. It is brought to the part, its position is adjusted, the quill rests against the part, holding it in the desired position, the position of the quill is fixed by turning the corresponding handle. After that, the position of the tailstock is fixed with another locking handle.
In some models, the tailstock is designed not only to support massive or long parts in a given direction, but also to process them.
To do this, depending on the operations performed, the corresponding equipment is fixed on the quills – cutters, taps, drills. The additional center of the machine on the tailstock can be stationary or rotating. The rotating rear center is made on high-speed machines, for removing large chips, turning cones.
Caliper
The support of a lathe is a movable part on which tools for machining parts are attached. Thanks to the special design of this unit, the cutter can move in three planes. Horizontal movement is provided by guides on the frame, longitudinal and transverse slides.
The position of the cutter relative to the surface of the machine (and the part) is set by a rotary tool holder. In each of the planes there is a latch that provides retention in a given position.
The holder of the cutter can be single or multiple. The tool holder, most often, is made in the form of a cylinder with a side slot into which a cutter is inserted, which is fixed with bolts. On simple machines, the caliper has a special groove into which a recess is inserted on the bottom of the holder. This is how the cutting tool is fixed on the machine.
Garage lathe: parameters
First of all, determine the mass and type of connection. When choosing a mass, you should not strive to find the lightest machine. Very light ones do not give stability, they can vibrate during operation, which will affect the accuracy of work. Yes, it is problematic to install heavy machines, but installation is a single event, you will have to work regularly. Therefore, weight is far from the most basic selection criterion.
The type of connection – single-phase or three-phase – this is already more important. And then, three-phase can be connected to 220 through special starters. Of the electrical characteristics, engine power is also important. The higher it is, the greater the rotation speed the lathe can develop. These are common points. There are also special ones:
- The diameter of the workpiece that can be processed on the machine. It is determined by the diameter of the processing above the bed and above the caliper.
- Workpiece length. Depends on the move.
- List of operations.
- The maximum number of revolutions.
- The adjustment method is smooth, stepped.
- Possibility of reverse.
The dimensions of the workpieces are directly related to the dimensions of the machine. So here we have to look for a reasonable compromise. Usually you don’t want to clutter up the garage too much, but you need to process the overall details.
Micro and mini lathes
In order not to clutter up the garage, you can find mini or micro lathes. They are very small in size and light in weight. For example, PROMA SM-250E micro lathe for garage has dimensions of 540*300*270 mm and weight is 35 kg. It can process workpieces with a length of 210 mm and a diameter of 140 mm. Smooth speed control from 100 to 2000 rpm. For the size, it’s not that bad.
Despite its small size, it can perform the following operations:
- surface grinding,
- thread cutting;
- drilling;
- countersinking;
- deployment.
It is also possible to grind parts, knurling, tool sharpening. The main operations, as you can see, are present. The disadvantage is that you cannot process any large parts on machines of this type. And another disadvantage of this particular model is the price. This garage lathe costs from $ 900.
In the same category there are Chinese JET BD-3 and JET BD-6 (price $500-600) and domestic KRATON MML-01 (price $900), Encore Corvette 401 ($650), German Optimum – from $1300 to $6000 $; Czech Proma – from $ 900,
Floor options
Here the choice is not so wide, because both prices and mass are much higher. There are several proven models that can be installed in the garage.
These are the so-called school machines – TV 4 (its improved version of TV 6), TV 7 and desktop version TV 16. With a mass of 280 kg (TV 4) and 400 kg TV 7, it is desirable to have a separate foundation. If you just put it on a concrete floor, it will break it.