Motor Shaft Machining: What You Need to Know

Motor shaft machining is the process of manufacturing precise motor shafts, which are used in many applications. Understanding the concept of motor shaft machining plays a vital role in using it correctly in the applications.

The guide below captures a detailed insight into the subject, so let's read it.

What is Motor Shaft Machining?

Motor shaft manufacturing is a process of manufacturing that transforms the metal rods into the parts that rotate, and these parts are then used in electrical motors.

The operation of the shaft impacts the durability and performance of the machine. There are different types of motor shaft manufacturing like milling, EDM and grinding.

Types of Motor Shafts

There are different types of motor shafts, and the section below discusses each.

Hollow Shafts

Hollow shafts are suitable for applications that require light weight, like aerospace. They have a center hole that allows fluid and components to pass through.

Tapered Shafts

Tapered shafts are used in gears and pulleys. They have taps on their diameter, reducing the length gradually.

Threaded Shafts

Threaded machined shafts have internal and external threads in them, which are matched to the part that is assembled with them. These shafts are used in applications where attachment and detachment are quite common like plumbing and electric work.

Keyed Shafts

Keyed shafts have a keyway cut, which helps secure components like gears, sprockets, and pulleys. These shafts help create connections in applications related to high torque, like pumps and motors.

Splined Shafts

These machined shafts have splines and grooves that can fit in similar splines in the component. It creates a very strong connection, offering excellent power transmission.

Splined shafts are used in applications like automobile transmission and gear couplings.

How Motor Shaft Machining is Done?

Below is the step-by-step process of machining a shaft:

• The first stage is the design and programming stage, where the design of the custom-machined shaft is finalized and programmed.
• A CAD file is created in the software, which has instructions in the form of G-code to instruct the CNC machine.
• The CNC machine is then set up for manufacturing shafts and for the process of machining, it is important to select the right type of machine.
• The workpiece is then prepared and subjected to the machine choosing the right tool.
• The CNC machine rotates the shaft, and the cutter removes material, it requires appropriate monitoring to ensure the quality of the custom shafts.
• There are different types of surface finishing options that help improve the surface of the shafts. Bead blasting and anodizing help enhance the surface of the shafts.

Various CNC Machining Techniques for Motor Shafts

Motor shafts are manufactured using different CNC machining methods, which are discussed below:

CNC Milling

CNC milling has a small and powerful chisel that moves around the shaft so that required grooves and shapes can be created so that the other parts can easily fit into these grooves.

CNC Turning

CNC turning is the process that machines the shaft and turns it into a cylindrical shape. The shaft keeps spinning, and the tool cuts the component.

CNC Drilling

CNC drilling is opted for making holes and channels in the shaft. It is a drilling process that is carried out by a CNC machine in a precise way.

CNC Grinding

CNC grinding consists of a spinning wheel that moves against the shaft and makes the surface smooth, ensuring the exact size. It helps in adding finish to the shaft’s surface.

Electrical Discharge Machining (EDM)

EDM uses electrical vaporization of material. It helps engrave complex shapes to create features on the shafts.

Various Machining Materials in Motor Shafts

Motor shafts can be made using a wide range of materials, and some of these are discussed below:

Carbon Steel

Carbon steel is used in motor shafts because it is highly machinable, can withstand heat treatment and also has a high tensile strength. One of the commonly opted grades of carbon steel is 1045, used in pump shafts.

Stainless Steel

Stainless steel is a material that is selected to deal with the issue of corrosion resistance. Stainless steel grades 304 and 316 are usually opted for manufacturing shafts used in environments exposed to chemicals and moisture.

Alloy Steel

Motors that require a tough and strength-oriented property are manufactured using alloy steel. The grades of alloy steel usually opted for the shafts are 4140 and 4340, which help to cater to heavy duty industrial applications.

Brass

Brass is used in applications that need shafts with corrosion resistance and high machinability. Hence, when it comes to light-duty machines, brass shafts are opted for.

Aluminum

Aluminum is a lightweight material that offers resistance against corrosion and is also machinable. Hence, applications that need a lightweight shaft usually opt for aluminum, especially in drones.

Titanium

Titanium is used in applications that require corrosion resistance and excellent strength-to-weight ratio. Such properties of titanium make it suitable for aerospace applications.

Nickel Alloys

Nickel-based alloys like Inconel can be used in manufacturing shafts as they offer corrosion resistance and also strength against high temperatures. Such motor shafts are used in turbines and other applications that are subjected to high temperatures.

Cost Considerations in Motor Shaft CNC Machining

The factors that impact the cost of CNC machining motor shafts are the following:

Material Costs

The cost of a motor shaft is dependent on the material type used for manufacturing it. Materials like carbon steel are less expensive, but titanium is more expensive.

Hence, the material is selected based on the required properties, and the cost is impacted.

Machining Processes

There are various processes to choose from when it comes to machining motor shafts. Complex methods of machining, such as laser or EDM, are more expensive than the basic ones, such as CNC milling and CNC turning.

Tooling Costs

The cost of cutting tools is related to the process of machining; tools also wear out with the passage of time and may need replacement. Hence, high tool wear leads to increased tool costs.

Labor Costs

The machining process, if complex, requires more labor effort and this increases the cost of labor. You may need to train and invest more into your labor for complex shapes of motor shafts.

Quality Control

Implementing strict quality control is very crucial to ensure that the final product comes out as expected. Hence, it requires investment in testing and monitoring the quality, which adds to the cost.

Surface Finishing Options for Motor Shaft Machining

There are different surface finishing options for motor shaft machining, and some of these are as follows:

Passivation

The passivation process is a surface finishing process that is used for stainless steel shafts. It consists of cleaning the surface of the motor shaft using an acid.

It helps remove contacts and free iron and allows the creation of a layer of passive chromium oxide, enhancing corrosion resistance.

Anodizing

Aluminum shafts are also anodized so that a layer of oxide, which is hard and corrosion-resistant, appears on the surface. Anodizing also improves the aesthetics of the shafts by adding colors.

Electroplating

Electroplating consists of depositing a layer of metal like zinc and nickel in the shafts; it enhances the wear resistance and corrosion resistance of the shaft.

Bead Blasting

Bead blasting involves releasing high-pressure balls of steel or particles of glass to clean the shaft surface. It helps to create a dull and clean look on the surface of the shaft.

Nitriding

The process of nitriding consists of using heat treatment which carries out diffusion of nitrogen in the steel surface. It creates a wear-resistant and hard layer on the shaft, enhancing its fatigue resistance.

Carburizing

Carburizing can enhance the surface of the motor shaft with a carbon layer by adding surface hardness. This process ensures that the wear resistance is enhanced and the shaft ductility is maintained.

Phosphating

The process of phosphating creates a layer of crystalline phosphates that are insoluble on the surface of the shaft. It ensures corrosion resistance and creates a suitable base to add further paint and coating.

Thermal Spraying

Thermal spraying involves spraying a coat on the surface of the shaft, which is then heated. It ensures thermal insulation and wear and corrosion resistance on the motor shaft.

Quality Control in Motor Shaft Machining

In motor shaft machining, the significance of quality control cannot be ignored. Appropriate inspections ensure that the shaft's surface finish, dimensions, and properties of the material are aligned with the application requirements.

There are many methods for quality control like coordinate material, surface roughness testing and hardness testing. Regular checks on the motor shafts ensure that they are up to the specifications.

Advantages of DEK's CNC Machining Motor Shafts

As a renowned CNC machining service provider, DEK offers high-quality motor shafts. These shafts are manufactured using advanced CNC machining equipment.

The equipment ensures accuracy in dimensions, and an expert team of skilled engineers chooses the right materials based on the application needs.

DEK not only focuses on using high-end machines but also ensures that it has an experienced team of operators and engineers. It boosts the productivity and quality of the machining processes.

The final output of the shafts has an excellent surface finish, ensuring you attain the finest quality custom motor shafts.

Conclusion

Motor shafts play a vital role in many applications, and understanding them in detail helps in choosing the right motor shaft material, surface finish, and manufacturing process.

As you have gone through the guide above, you must have learned about the variations that are offered in this subject.