Air Cooled Or Water Cooled CNC Spindle , Which Is Better?

by FORSUN CNC mechanic

Friends who are considering buying a CNC router will always ask “air-cooled or water-cooled CNC spindle, which is better for my job?” The engraving machine spindle is an electric spindle that can be processed at a high speed, which is widely used in some small and medium-sized engraving machines. The equipment is mainly used for high-speed engraving, drilling, milling, drilling, etc., involving a wide range of industries.

According to different cooling systems, the spindles of industrial CNC wood routers are divided into two types. One is water-cooled, and the other is air-cooled. The spindle motor is the most important part of the CNC wood router machine, so we should choose a more durable spindle motor to suit our work. As a professional CNC factory, the following content FORSUN CNC will compare the water-cooled and air-cooled spindles, hope it will be helpful to you.

Air Cooled VS Water Cooled CNC Spindle

Cooling effect

The heat dissipation of a water-cooled spindle is much better than that of air cooling: the water cooling method uses water circulation to cool the spindle. After the water is circulated, the temperature of the spindle can be kept below 40 degrees, and its cooling effect is much better than air cooling.

Noise

The water-cooled spindle motor is basically noise-free. The air-cooled spindle is noisy.

Engraving and cutting performance

Compared with the water-cooled spindle, the air-cooled spindle has larger torque and stronger cutting force.

Service life

The service life of a water-cooled spindle is longer than that of an air-cooled spindle: the service life of water-cooled spindles can be extended by replacing water or using industrial water coolers and other human factors.

Accuracy

The accuracy of the water-cooled spindle is higher than that of the air-cooled spindle: the axial and radial runout of the water-cooled spindle is basically less than 0.003 mm.

Price

Air-cooled spindles with stable performance are slightly more expensive than water-cooled spindles: many small engraving machine manufacturers will use water-cooled spindles in the initial stage, but the performance of water-cooled spindles is not as stable as that of air-cooled spindles. This is mainly reflected in the operation of water-cooled spindles. It is easily affected by the ambient temperature. In winter, the water tank of the water-cooled spindle is very easy to freeze, and finally, the spindle cannot be started and eventually broken.

Working environment

The use of an air-cooled spindle is less restrictive: since the water-cooled spindle needs to be connected to a water pump, a bucket is needed to hold the water. And it needs to be connected to the water pipe. Since the water cooling spindle needs to be connected to a water pump, a bucket is needed to hold the water. And it needs to be connected to the water pipe.

If you are in a cool place (such as Russia), please use the air-cooled spindle of an industrial wood CNC router machine. If you are in a high-temperature place, the water-cooled spindle of an industrial CNC wood router machine will be more suitable for you. Because the cooling capacity of water is stronger.

Single-use time

The water-cooled spindle motor is more suitable for long-time engraving than the air-cooled spindle: the water-cooled spindle cools the heat generated by the high-speed rotation (18,000 or 24,000 RPM) of the spindle through water circulation. After the water cycle, the temperature (usually tested) will not exceed 40 degrees.

Therefore, if you want to buy a multi-head CNC router machine or a 4-axis CNC router machine with multiple rotating-axis, which is mainly used for engraving applications, it is best to use a water-cooled CNC spindle.

Common problems for CNC spindles

The main shaft is the heart of the machine. The following are some troubleshooting tips to ensure that your CNC machine is running at its best performance.

My spindle is running abnormally hot
Confirm that the cooling system (liquid, compressed air, electric fan) is operating normally. Monitor current consumption during cutting. Higher than normal current indicates that the tool is stuck or the feed speed is too fast. If the spindle is noisy and cannot be rotated by hand, it may be a bearing problem. Send to PDS for further diagnosis.
The spindle stops rotating after a few seconds of starting
The reason for this situation may be that the startup time is too short. Properly extend the acceleration time before the spindle works, and start engraving after reaching the running speed. The current protection may also be caused by the lack of phase of the spindle, which requires us to check whether the connection of the spindle motor is correct.
Noisy spindle or spindle vibration
Basically, these problems are hardware problems. The bearings are worn and the spindle has a lot of runouts, and it needs to be returned to the factory to replace the bearings or replace with a new spindle.

Popular skills for CNC spindles maintenance:

Popular practical skills for water-cooled CNC spindle maintenance:

Please use hooks to clean the water outlet and water inlet frequently to prevent debris from clogging the water pipe.

After removing the spindle from the CNC router machine, use an air gun to blow away the residual water in the cooling chamber of the electric spindle.

If you do not use water to cool the spindle motor for a long time, you should seal it; when starting, in addition to removing the rust on the surface with gasoline, you should also pay attention to the following points:

Lubricate with oil mist for 3-5 minutes, twist the shaft by hand, and feel smooth.
Use a megohmmeter to check the insulation, usually greater than 10 megohms.
Turn on the power, if everything is normal, please run at 1/3 of the rated RPM for 1 hour, if so, speed up the operation of 1/2 of the rated RPM for 1 hour, if everything is normal, then run at the full RPM for 1 hour Run.

How to maintain the water-cooled spindle?

Woodworking engraving machine spindles are divided into water-cooled and air-cooled spindles. The air-cooled spindle only needs to occasionally clean the dust on the fan blades; while the water-cooled spindle needs good maintenance and maintenance to be used for a long time, we will come next Talk about how the water-cooled spindle should be maintained and maintained daily.

The temperature will have a certain impact on the woodworking engraving machine and the water-cooled spindle. If the room temperature is very low, it will cause the oil and the water in the water tank to freeze. When using the machine in winter, it is best to ensure that the temperature of the processing environment is not too low. At least it must be kept above zero.
The water-cooled spindle of the CNC woodworking engraving machine is equipped with a water circulation system. If the water inside is not clean, it will easily cause scale and block the water pipe, so it is best to use pure water.
In winter, the temperature is very low. After the work is completed, the water should be emptied in time, otherwise, the water pipes and water tanks may freeze and crack due to the freezing of the water.
The water in the water-cooled spindle of the woodworking engraving machine should be replaced frequently, especially in summer, if the water temperature is not enough, it will not be able to cool down, and the service life of the water-cooled spindle will be reduced if the time is long.

Practical skills of air-cooled CNC spindle:

The air entering the electro-spindle should be dry and clean. Please ensure this.
If it is not used for a long time, the main shaft should be oil-sealed; when starting, in addition to removing the rust on the surface with gasoline, the following points should be noted:

Lubricate with oil mist for 3-5 minutes, twist the shaft by hand, and feel smooth.
Use a megohmmeter to check the insulation, usually greater than 10 megohms.
Turn on the power, if everything is normal, please run at 1/3 of the rated RPM for 1 hour, if so, speed up the operation of 1/2 of the rated RPM for 1 hour, if everything is normal, then run at the full RPM for 1 hour Run.

To sum up

For CNC spindle air cooling or water cooling, which one is better? We suggest that you consider the purchase budget and local natural conditions, such as local water resources, temperature, and other factors when choosing a cooling method.