Undercut Machining: Process, Types, Applications & Tips
The machining process is capable of producing components with versatile features. As much as the features on the face of the parts are significant, the features in the form of cavities and contours play a vital role.
To achieve these undercuts and cavities, undercut machining is opted for. If you want to know more about it for your projects, read the guide below.
What is Undercut Machining?
Undercut machining creates surfaces of the parts that cannot be attained through traditional machining tools. The standard tools cannot create contours and cavities as they are not accessible overhead.
The experts in machining use precise tools for creating these undercuts. To have slots created, the CNC cutting tools need advanced features and can create internal as well as external undercuts.
What is a CNC Undercut?
Undercuts consist of a CNC-machined part, which is recessed over another one.
Undercut in CNC Turning
The process of CNC turning creates undercuts, which are on the internal side of the machined component. The undercut is recessed in the diameter.
The length of the undercut in the turning method should be 1.5 threads, and the diameter must be 0.38 mm smaller than the diameter of the minor thread. Undercuts are present at the end of the parts that have threads, and hence, the cutting tool may have the right clearance.
Undercut in CNC Milling
The process of milling consists of mounting cutting tools in the machine spindle. In certain cases, the undercut machining operators cut the material in such a direction that the feature cannot be seen from the spindle’s angle. It requires special tools so that they can access the part that is behind the material that is visible.
The Importance of Undercuts in Machined Parts
The machined parts that have undercuts are required to have the design and functional objectives achieved. The machinists avoid these undercuts in the designs of the components, as they are complex. These features are significant in securing the mechanisms of locking so that the components can be assembled. This eliminates the need for having fasteners.
The undercuts also reduce the machined parts' weight and are used in industries that need high payload capacity and functionality, like aerospace. The undercut machining process allows to create the cavities for the parts on the internal side and does not compromise the structural integrity.
These undercut features help to ensure functionality in the hydraulic system. They also allow pathways for the liquids to move through the given channels.
Step-by-Step Guide to Undercut Machining
The step-by-step guide for undercut machining is given below.
- The first step requires evaluating the shape of a component in the profile to decide whether it needs external undercuts or internal ones.
- As you have assessed the geometry, you can now decide on the cutting tool and choose the one that suits it. Every task needs a specific CNC undercut cutter, which helps to achieve the required depth and profile.
- Now, prepare the machine for the machining process and enter your design in the CAD software. You can mount the workpiece on the spindle, which is special for undercut machining, and clamp it on the worktable.
- The CNC machine then starts working once you have attached the right tool and unclamped the workpiece. The machines work using the program that has been added and move along the defined path.
- The parts, when machined, are then inspected to see if the dimensions match or not, and the quality of the parts is also assessed.
Typical Types of Undercuts in CNC Machining
There are different types of undercuts in CNC machining, and these are as follows:
One-sided Undercut
One-sided undercutting of the component has an asymmetrical recess that is created on one side of the component. These are opted for such machined parts that need precise grooves on a specific side to support the assembly of parts.
Dovetail Undercut
Dovetail undercut creates a connection between the two parts, which involves recessed and wedged sections. The wedge section locks itself in the part that is recessed, and the two parts are assembled. It is a standard feature that helps to make components for many woodworking applications.
T-slot Undercut
T-slot undercut has a fixture in the T-shape that holds the components together. The head of the bolt enters the slot and slides through the length, creating a secure connection. This T-slot undercut involves using an end mill with a T-slot cutter to create a T-shape.
Tapered Undercut
Tapered undercut involves milling surfaces that have a narrow side. The tapered undercuts are suitable for such applications that need rotational and tight fit between the components.
Spherical Undercut
The spherical undercuts have a curved surface that looks like a sphere. These undercuts are used to create parts that need rotational movement, such as ball joints and bearings. The ball nose end mills are opted for the CNC tools, which help to create the machined parts.
Threaded Undercut
The threaded undercuts consist of internal threads like screws and bolts. These undercuts have features that are needed for screwing, and specialized taps and thread mills are used for creating them.
Special Tools for Machining CNC Parts with Undercuts
There are different tools that help with CNC machining for undercuts, and some of these tools are as follows:
Dovetail Cutters: These cutters consist of cutting edges that are angled and help to create dovetail features for the undercuts. They have separate blades placed in the shape of a dovetail to create the profile in one go.
T-slot Cutters: T-slot cutters consist of a cutting edge that is straight and helps to create slots that are smooth in a single go.
Lollipop Cutters: Lollipop cutters consist of cutting tools in the shape of lollipops; they create undercuts with bottoms having sphere-like shapes.
Keyway Cutters: The keyway cutters are meant for creating features that have an undercut. The tool used for it is unique enough to cut the part to the required depth.
Undercutting End Mills: The undercutting end mills are equipped with cutting edges at the tip and the sides. It can create cuts in spherical shapes and varied geometries.
Application of Undercut Parts
The application of undercut parts can be seen in different industries, and some of these are as follows:
Mold Manufacturing: The mold designs are complex and have intricate geometry that can be created with undercut machining.
Automobile: Undercut machining is used in making shafts and gears, which enhances the mechanical engagement and ensures that the seals are leak-proof in O-rings.
Electronics: The undercuts in housing help with flexibility in assembling; T-slot undercuts also help to facilitate the attachment of parts.
Aerospace: The undercut components help with reducing weights and integrating the grooves so that the wiring can be channeled.
Practical Tips for CNC Machined Parts with Undercuts
When CNC machining components that have undercuts, some of the tips that can help you achieve the finest shapes are as follows:
- To get the parts with an undercut manufactured, make sure to partner with experts. Machining undercuts requires expertise and special tools, and hence, to ensure that the quality and precision are up to the mark, a highly skilled professional can only help.
- Undercuts must be avoided unless necessary. Using them in the design may add to the complexity. Hence, it is suggested to eliminate the complications of design and achieve highly accurate parts.
- Try to keep your undercuts capable of being cut through standard tools rather than custom ones. The time taken by custom tool manufacturing is long and expensive. Hence, it is suggested to have the standard tools utilized for the purpose of undercut machining.
- The depth of the cut and the cutting tools must be compatible with one another. There is a limit to the depth that you can achieve with the cutting tools.
Choose DEK to Machine CNC Parts with Undercuts
Undercut machining requires professional services, and we at DEK are equipped with specialized tools and expertise that are crucial for it. If you are looking to have the parts manufactured with undercuts, get in touch with us. We will provide you with accurate and precise custom components.
Conclusion
Undercut machining is precision-oriented machining, which requires a detailed understanding. So, the guide above must have familiarized you with everything in detail. You must now be in a position to use it in your projects, having sound knowledge.
