What is the optimal spindle for CNC?

The CNC spindle is the most important part and the loaded unit. For the correct choice, always take into account that the motor power and the mechanical strength of the kinematics must exceed by 2 times the calculated values. This is required for the safety of expensive parts when podklinivanii.

basic information

Programs for CNC machines are written according to the rigidity of the design and the maximum spindle speed. When milling, the probability of breakage of the rotating tool from heating or fatigue of the metal must be taken into account. Therefore, often put safety couplings, designed for the specific dimensions of the motor shaft and the diameter of the cartridge.

All programs for CNC machines are first worked out step-by-step without moving the axes. When the user is 100% sure that the spindle cams will not be touched, then they start working with movements in step mode or single cycles. When the test is finished without workpiece, proceed to the direct cutting of the part.

The CNC spindle is an expensive unit and the most powerful one, nevertheless it can easily be disabled if careless handling of machinery. Some systems have complex calculations of correctors, incorrect determination of which turns into long repairs. To work on each new machine, a preliminary retraining of the operator is required, even if he already has experience in a similar rack.

Options

The CNC spindle should be selected according to the following criteria:

• Type of cooling unit: air, liquid.
• Spindle motor power and gear ratio.
• Engine's type.
• Type of bearings and method of lubrication.
• Operating modes, type of braking system.
• Positioning accuracy and type of tracking sensor.
• Spindle Mounting

In addition to these parameters, the motor design itself is also important: the number of windings, the type of rotor, the way of removing and feeding the load to the windings. Take into account the torque and the possibility of adjustments for the centers of the node relative to the feed axes. Cartridges also need to be changed: self-clamping, hydraulic, manual, pneumatic.

The spindle for CNC is selected taking into account the possibility of changing consumable parts. You should see the options available for bearings, which are available in warehouses, find out about the delivery time. It may be that because of a small consumable will stand production for a long period, or it will be necessary to pay a tenfold price for the manufacture of the part. A small spindle for a CNC milling machine should have a lightweight construction and small dimensions.

What can I do the site myself?

The spindle for the CNC milling machine for processing wood, plastic and other soft materials can be a conventional electric drill. It is important to set it to the level and measure the beat of the cutter. This is a cheap option, allowing to improve the existing design.

As a rotating axis, any engine with an accurately exposed tool is suitable. A reliable and rigid fastening of the spindle is selected. The axial play should not be more than 0.01 μm for most openings. A drill is used, a revolving drill, it is possible to adapt even the engine from a washing machine or a sewing machine. Which spindle is suitable in a particular case depends on the goal. It takes into account the type of material, the required accuracy of the dimensions of the part, the load in the automatic cycle. You can also order ready-made solutions in the online store.

Custom-made motors

Numeric program control (CNC) is used to improve the accuracy of the parts produced and to reduce the time spent on production. For a single product, the cost of equipment exceeds the amount invested in its release. It will be cheaper to order a part in any company engaged in metalworking.

For a self-made spindle, ready-made motors are ordered. DC motors, synchronous and asynchronous, are popular. Turnover of 12 thousand for such engines - not the limit. Additionally, a gearbox with manual or automatic drive can be used. Powerful spindle motors require a steady supply. This is their drawback. But if you put a simple drive and a motor with feedback, then on this machine you can already handle more complex products. An additional axis is introduced into the CNC, which can hold not only the milling cutter, but also the cylindrical parts.

The better the engines to order?

The factory motors have already carried out balancing of the shaft and the bearings are selected with a minimum beat. It remains only to put the finished engine on a standard mount and align the indicator stand. The accuracy of milling is required in the manufacture of printed circuit boards, parts of kinematics.

Synchronous motors showed themselves well when making jewelry parts by engraving. Permanent motors have low noise levels during operation, which can be useful for managers trying to improve their production. However, they have the property of basking while working at high speed. Therefore, it is necessary to supply separately and cooling, at least air.

Selection of professionals

More expensive engines for spindles are necessarily equipped with liquid cooling. They have a higher positioning accuracy, a sufficiently powerful torque, and reliability is higher than the specified several times. Usually they are installed on 3-4 bearings, and not on 2, as classic motors. Due to this, the minimum beat of the tool or part in the chuck is achieved.