Spindle for CNC milling machine - options, making your own hands
Milling machine spindle, equipped with CNC, is the most important structural element of such equipment. The cutting tool is fixed in this detail, and it is she who transmits the rotation to him.
CNC milling machine spindles, placed on a mobile portal
Options of spindles for the milling machine
Engraver
If you are interested in the cheapest spindle for your homemade CNC milling machine, then you can use a serial engraver. The power of such a device is 125 W, and the price starts from 500 rubles. However, such a spindle has a number of significant disadvantages. At low speeds, it emits weak torque, that does not allow to use it for processing of preparations from metal. Therefore, such a spindle can only be used for engraving and for processing softwood blanks with small diameter cutters..
The spindle from the engraver will be, apparently, the most budget option
Drill
The second version of the spindle for a CNC milling machine, made with their own hands, Is a drill, the cost of which starts from 2000 rub. compared to the engraver, such a device works much quieter, very slightly loses torque at low revs, differs in a qualitative cartridge clip.
Bormashina «Profile M-01»With jaw chuck, which allows you to use nozzles with shanks of different diameters
DC motor
The spindle of the milling machine can be made with your own hands, using DC motors, working from voltage 12-48 St.. Power of such motors, able to develop in a minute 12 000 revolutions, is 400 W. This spindle motor has the following advantages: lack of loud beating and loud noise at work, using a standard ER11A collet.
If you add such a spindle to a simple electronic device, then with the help of CNC you can control the number of revolutions. This spindle also has disadvantages, which include the need for additional power supply, low power, significant heating during operation, which necessitates its cooling. Due to the low power, the self-made milling machine with such a spindle is suitable for processing only soft materials..
Spindle of the self-made milling machine with ChPK from the DC motor
Milling machine and straight grinder
As a spindle for self-made CNC machines, you can also use straight grinders and milling machines. If you take as a spindle a milling cutter model Enkor FME-850 W., then you will have a machine, on which it is possible to process not only wooden preparations, but also products from plywood and non-ferrous metals. Which is convenient, complete with such a milling cutter is a collet 6 mm, for which there are standard adapters 3 to 6 mm. Using this adapter, in such a spindle you can install cutters with diameters of 0.1-6 mm.
Not all models of milling cutters have such a collet in their kit, which does not allow them to be used to equip CNC milling machines. The milling cutter Enkor FME-850 W has disadvantages, which include high volume during operation and the absence of an electronic device in the design, which is responsible for changing the number of revolutions, which does not allow to use it for processing of polymeric materials (this requires small turns of the cutter).
Using a vertical milling cutter as a machine spindle
Router Sparky
If on a CNC milling machine, which you made with your own hands, it is necessary to process polymeric materials, then it is better to use Sparky cutters as a spindle for it. The power of such milling cutters can vary within 500-1050 W. In the design of models, whose power starts with 750 W, an electronic device is provided, which is responsible for changing the number of revolutions, therefore, they can be used for processing polymeric materials (acrylic, Pvc, double-sided plastic, model plastic, etc.). To process such materials, the milling machine must be able to rotate at low speeds, without losing its power. This prevents heating in the area of processing and melting of plastic, and high power ensures sufficient productivity of the milling process.
Fraser Kress
Kress milling cutters are optimal in terms of price-quality ratio, which can also be used as machine spindles, equipped with a CNC system. The big advantage of such milling machines is that, that their design provides a system, which normalizes the beating.
Milling cutter Kress as a spindle
Professional spindle
If desired, you can equip your homemade CNC milling machine with a professional spindle, in the design of which a liquid cooling system is provided. In addition to an efficient cooling system, in the design of such a spindle is 3-4 bearing, which significantly increases its reliability and accuracy of processing (it is worth noting here, that in spindles of the usual household equipment it is established only 2 bearing). The advantages of such devices include the absence in their design of fast-wearing brushes and low noise during operation. The biggest disadvantage of such spindles is that, that their value starts from 7000 rubles. in addition, you will have to spend extra on the purchase of a frequency converter for the cooling system, which costs about 6000 rubles.
Factory rotary spindle for CNC machine
Spindle for CNC machine with your own hands
Most often for CNC machines, which are made with their own hands, use a device for cutting metal "Dremel" or Chinese analogues of such equipment, which can be easily purchased in any city in Russia.
Meanwhile, to use such devices as the spindle of the milling machine is not quite correct, as they very quickly become unusable. That's the whole point, that in their design only one persistent bearing is provided, which does not allow them to accept lateral loads for a long time, characteristic of milling.
Virtually any technological operation for milling wood and metal is performed with lateral loads on the cutting tool and, in accordance, on the design of the spindle.
Spindles are often purchased for homemade milling machines, in which collector motors are installed. Such devices are inexpensive and work well at high speeds, and at low significantly lose their power. These problems can be avoided, if you install a spindle with a brushless motor on your machine.
An inexpensive CNC milling machine can be used as a ready base, and to make a spindle for it with your own hands, you will need the following components:
- electric motor of collectorless type (NTM series 50-50 580 KV / 2000 W.);
- elongated shaft;
- controller for collectorless motor;
- servo tester.
Collectorless electric motor ARES PRO SPEC
Servo tester, which is necessary to adjust the spindle speed, can be purchased inexpensively. It is important to pay attention to the convenience of attaching such a device to the CNC milling machine.
The extended shaft of such engine allows to fix a mill directly on it by means of a collet clip.. To do this, two bearings are mounted on the motor shaft with the help of holders, the motor itself also has two built-in rolling bearings. The design assembled in this way perfectly withstands lateral loads, arising from milling on the machine not only metal, but also softwood blanks.
The scheme of installation of bearings (click to enlarge)
Controller, which you will use for the spindle motor, has the function of stabilizing the speed when the load changes. This function is especially useful for performing technological operations of finishing wood blanks, plastic and metal.
After such a simple and low-cost modification, you will have a CNC milling machine, spindle speed which can be adjusted by means of the servotester (ensure the stability of the speed will be the controller).
