CNC Machining
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Fathom’s CNC Machining Service
for Your Most Demanding Applications
Do you have unique machining needs? Complex part geometries? Tough materials? Extremely tight tolerances? Fathom’s CNC machining service takes on challenging jobs like these every day – projects that other shops back away from. Here at Fathom, it’s one of our core competencies.
CNC machining is perfect for a wide range of applications. For customers in demanding industries like defense, aerospace, medical and automotive, it meets their need for precision, repeatability and accuracy. For others, it provides a cost-effective way to get the parts they need at a reasonable cost.
Are you looking for a manufacturing partner who can keep up with your needs and lead your thinking? Then it’s time to talk to us about our comprehensive CNC machining services.
How Does Precision CNC Machining Work?
Do you have unique machining needs? Complex part geometries? Tough materials? Extremely tight tolerances? Fathom’s CNC machining service takes on challenging jobs like these every day – projects that other shops back away from. Here at Fathom, it’s one of our core competencies.
CNC machining is perfect for a wide range of applications. For customers in demanding industries like defense, aerospace, medical and automotive, it meets their need for precision, repeatability and accuracy. For others, it provides a cost-effective way to get the parts they need at a reasonable cost.
Are you looking for a manufacturing partner who can keep up with your needs and lead your thinking? Then it’s time to talk to us about our comprehensive CNC machining services.
Three basic types of CNC machining are drilling, milling and turning:
CNC Drilling // Drill bits are used to make cylindrical holes in the workpiece. Usually, these holes are used for screws or other fasters. Normally, these holes are perpendicular to the surface of the workpiece. But specialized tools can also drill holes at an angle. Other common drilling operations include:
- Counterboring // This type of drilling creates a stepped hole so that the head of a bolt or screw is flush with the surface of the material being machined.
- Countersinking // Countersinking is like counterboring. But it creates a conical hole instead of a stepped one. That enables fasteners to sit flush with the surface of the workpiece.
- Reaming // Reaming is an operation that improves the accuracy and smoothness of pre-drilled holes. It helps the CNC machine achieve tight tolerances and high-quality finishes often required by the aerospace and automotive industries.
- Thread tapping // This operation creates internal threads within a pre-drilled hole. They enable bolts or screws to be attached to the part.
CNC Milling // This machining method uses CNC to control a rotating cutting tool. It removes material from the workpiece to create a finished part. Milling machines can cut at multiple angles and move along multiple axes:
- Three-Axis Milling // This type of milling machine can cut three surfaces of a part along its X, Y and Z axes, while the workpiece remains stationary.
- Four-Axis Milling // This type of milling machine can cut along the three linear axes (X, Y and Z). It adds an A axis, which enables the workpiece to be rotated around its X axis. This enables it to cut complex, precise shapes that aren’t possible with three-axis milling.
- Five-Axis Milling // A five-axis milling machine also enables the workpiece to be rotated along its Y-axis. It enables the machine to approach the part from all directions in a single operation. It also eliminates the need for the operator to reposition the workpiece to make more complex cuts. That saves time and money.
CNC Turning // In CNC turning, material is removed from a workpiece as it is being rotated at high speed on a lathe. It’s often used to create cylindrical parts. Common operations include straight turning, taper turning, facing, grooving and cutting:
- Straight Turning // The workpiece is rotated on a lathe as a cutting tool shapes it to a consistent diameter. It’s used to manufacture basic components like shafts, pins and rods.
- Taper Turning // As the workpiece rotates at high speed, the cutting tool gradually changes the diameter of the workpiece over its length. That gives it a tapered or conical shape.
- Facing // This operation removes material from the end of the workpiece. It ensures that the milling surface is perfectly perpendicular to the workpiece. It’s often the first step before additional machining is performed on it.
- Grooving // This is the process of cutting a recessed groove into the circumference of the workpiece. This feature is added when an O-ring needs to be integrated into the part, for example.
- Cutting or Parting // In this operation, the cutting tool slices completely through the workpiece, separating it into two sections. This enables several parts to be produced from a single piece of material.
Applications of CNC Machining Services
The applications of precision CNC machining are nearly limitless. CNC machining can be used to produce many types of parts from a variety of materials, including metal and plastic.
Fast turnaround times, efficient manufacturing and ease of use make CNC machining the ideal choice for prototyping and low-volume production. CNC machining services are commonly used in the aerospace, automotive, consumer, industrial, medical and technology sectors.
Aerospace // Precision CNC machining is widely used in the aerospace industry, where safety is paramount and there is zero tolerance for error. Aerospace applications require precise tolerances. Weight reduction is a major priority. CNC machining is often used to produce complex parts from aluminum and titanium and their alloys
Automotive // Like the aerospace industry, the automotive sector also values parts that are precise and lightweight. Safety is also critical. CNC machining is used for both prototype part development and production. Metal can be machined for external components such as engine blocks, gearboxes, cylinders and axles. Plastic can be machined for interior components for the dashboard, gauges, and trim. The automotive industry employs strict quality standards to ensure that all parts meet their specifications. Suppliers must also follow stringent quality processes.
Consumer // CNC machining is often used to build prototypes and production parts for consumer products. Examples include appliance components, utensils, fixtures and the enclosures of some smartphones and laptop computers. They are often machined out of aluminum because of their strength and light weight.
Medical // CNC machining is commonly used to produce components for the medical industry because of its precision and accuracy. Examples include instruments and devices used in medical procedures and rehabilitation. CNC-machined parts are also used in implantable components like hips, kneecaps, screws, pins and rods. CNC machining is used throughout the product life cycle, from prototyping to production.
Technology // CNC machining is commonly used in emerging technology sectors for prototyping and small production runs. Fast turn-around and low-cost setup make CNC machining an ideal manufacturing technique for this fast-paced industry. Part redesigns are easy to accommodate because parts can be produced quickly without tooling.
Industrial // Industrial equipment takes a beating in some of the world’s most brutal environmental extremes. Machines that work in these remote places need durable parts. CNC machining is used to build parts that can withstand temperature extremes, corrosive environments and repeated impacts.
What Does CNC Machining Make Possible?
Rapid Prototyping // Parts can be CNC machined in a matter of hours, making it easy to iterate part designs and accelerate your time to market. All you need to do is generate an updated CAD drawing. We’ll convert it to the code used to drive our CNC machine tools.
Fine Details and Tight Tolerances // Because the machine tools used in this process are computer-controlled, they can produce large quantities of parts with a high degree of accuracy and repeatability.
Excellent Accuracy and Repeatability // CNC machining can be used to produce complex parts with tight tolerances. That’s important for high-performance industries like aerospace, defense and automotive.
A Wide Selection of Materials // CNC machining can be used to process many types of materials, including durable plastics and high-strength, lightweight metals. They can be finished in a variety of ways to meet specific customer requirements.
Easy to Make Design Changes // Updating the design of a part is as simple as modifying the CAD file and then generating new code to drive the CNC machine tool. That’s it – no additional tooling or preparation is needed. You can immediately start machining the new version of your part.
Advantages
Produce Parts to Precise Specifications // CNC machining can produce simple parts with high precision and high accuracy, with tighter tolerances than injection molding or additive manufacturing. This makes components easier to assemble. They fit together more reliably because features align as they should. That saves time and reduces waste.
Ability to Produce Complex Shapes // CNC machining processes and cutting tools can produce many types of complex shapes with excellent accuracy and repeatability. Because they are so precise, CNC machines can produce almost any size and shape of part you can imagine.
Ideal for Prototype Parts // CNC machining is driven by the data in your part’s CAD drawing. It can produce accurate prototype parts in a matter of hours. You can also use it to iterate your way to a final design and get your parts into production faster.
Material Selection // CNC machining services can be used with a wide variety of materials, including many types of metals and alloys, plastics, phenolics and rigid foam.
Speed of Production // An automated CNC machine can run 24 hours a day, if needed, with minimal human interaction. That means it can produce your parts faster than other manufacturing methods that require more manual labor.
Reduced Waste // Unlike manual machining, which often involves a succession of trial parts until an accurate part is produced, automated CNC machines produce your parts the same way, each time. That results in less wasted material.
Affordability // A high level of automation is possible with CNC machining. That means less labor is needed to produce large quantities of parts. That makes it a surprisingly affordable manufacturing technology.
Disadvantages
Set-Up Time // Specialized knowledge and training are required to set up and operate CNC machines. Workpieces often require custom-made fixtures and jigs to securely position and hold them during machining operations.
Design Limitations // Some organic and irregular shapes may be hard to create using CNC machining. Also, CNC machining isn’t cost-effective if you only need to produce a handful of parts.
Part Size Limitations // Larger parts may cause some limitations in cutting accuracy. That’s because their weight can place stress on the material and could cause distortion. It may also be hard for work holding fixtures to keep them securely in place.
Operator Error // CNC machining is automated. But it’s still highly dependent upon the skills and problem-solving abilities of the operator who is setting up the job. Look for a manufacturing partner that has experience making the types of parts you need.
Part Geometry Limitations // CNC machining can’t be used to create cavities within parts or conformal cooling channels. That’s because there’s no way to get a cutting tool inside of a part. Finishing internal surfaces can also be problematic.
Key Considerations
When Designing for Precision CNC Machining
Work Holding // The geometry of the part will dictate how it will be positioned in the CNC machine and the amount of setup required. Manually repositioning a part can increase the chance of error. Repositioning will impact not only accuracy but often increases the cost of the project. Parts that have rounded or irregular shapes may be hard to secure before machining.
Tool Stiffness // The tool used to cut the part may vibrate during operation. Tool stiffness may result in a reduction in tolerances.
Work Piece Stiffness // Temperatures and cutting forces that arise during machining may cause the workpiece to vibrate, resulting in deformities. You can prevent workpiece stiffness by ensuring the design specifications call for the minimum wall thickness and a maximum aspect ratio of tall features.
Tool Geometry // CNC machine cutting tools have a cylindrical shape and a flat or rounded end. This can restrict the possible geometry of CNC-machined parts. For example, the inside vertical corners of the part will have a radius, even if a small cutting tool is used. Sharp inside corners may be difficult to achieve because of the shape of the cutting tool. If you require a part with sharp corners, you may need to use wire or sinker EDM cutting.
Tool Access // The workpiece cannot be machined if the cutting tool is unable to reach a surface. This limits parts that require hidden, internal geometries and sets a limit on the maximum depth of an undercut. For parts with complex geometries, internal cavities or deep undercuts, consider using metal 3D printing instead. Fathom can produce high-density metal parts using Direct Metal Laser Sintering (DMLS).
Material Hardness // Material hardness is a crucial factor for CNC machining. It can significantly impact:
- The ease of cutting
- Tool wear
- Machining speed
- The overall quality of the finished part
For hard materials, special tools are often required to withstand the increased wear and tear they cause. Instead of carbide steel tools, you may need to use tungsten carbide or diamond-tipped tools that are designed for this type of work. Improper machining techniques can cause excessive heat or tool wear, leading to poor surface quality.
If you require parts made out of tough, hard-to-machine metals or alloys, make sure your manufacturing partner has expertise in working with them.
What Precision Technologies Can CNC Machining be Paired With?
Some types of manufacturing methods, such as injection molding and certain types of additive manufacturing, may not be able to hold the tight tolerances that the customer requires.
In cases like these, parts can be manufactured with machinable surfaces that can then be milled or turned to achieve the tolerances required. Holes and other features may also be added after the part is built.
Alternatives to CNC Machining Services
While a CNC machining service is appropriate for creating many types of parts, it does have some limitations. For example, it can’t create certain features such as internal cavities or conformal cooling channels. These are easily made using additive manufacturing methods like DMLS.
For applications where large quantities of parts are needed, manual machining may not be able to produce parts at the required rate. Also, manual machining is impractical for operations where human physical limitations are a factor, such as processing hard materials.
As previously mentioned, CNC machining uses rotating tools to cut metal. That means it creates rounded corners. If you need square corners, then you may need to consider using wire or sinker EDM cutting.
For certain types of flat workpieces, laser cutting, water jet cutting, wire EDM cutting, photo chemical etching or metal additive manufacturing may be more efficient.
CNC Materials Available
Fathom offers a variety of plastic and metal materials for CNC machining. They vary from aesthetically pleasing surfaces for high-end consumer products to rugged, wear and corrosion-resistant metals that are designed for the world’s toughest environments.
For a complete inventory of metal and plastic materials, sizes and tolerances, please download our CNC material sheet.
Not sure what you need? Talk to a Fathom expert today!
Post-Processing & Finishing Options
Post processing is an easy way to ensure a uniform appearance from part to part. Some CNC machines may leave visible tool marks on the piece after production. Tool marks may vary from slight to obvious, depending on the material and CNC process.
Post processing is available for plastic and metal parts. This can include bead blasting to remove tool marks or painting to achieve a desired color.
Finishes for Metal //
- Standard Machined Finish
- Tumbled
- Bead Blasted (Sand or Glass)
- Polished
- Anodized
- Chemical Film
- Passivation
- Powder Coating
- Electro Polishing
- Electroless Nickel Plating
- Silver Plating
- Gold Plating
- Painting
Finishes for Plastic //
- Standard Machined Finish
- Flame or Vapor Polished (Acrylic Only)
- Powder Coating
- Tumbled
- Painting
Why Choose Fathom’s CNC Machining Services?
Fathom has the expertise and technology to help you meet your needs faster.
Fathom has an unmatched depth of expertise in CNC machining and the capacity to take on your projects. Our CNC facilities specialize in challenging applications. We work with extremely tight tolerances and exotic materials for use in medical or aerospace industries, for example. We even process specialized materials like Inconel and Monell, two of the world’s toughest alloys.
Fathom also has certifications at several of our locations to meet the highly specialized needs of your medical, aerospace or government industries, including ISO 13485, AS9100 and ITAR. View our certifications by location →
Our Fathom Experts recognize the value of having design and manufacturing collaboration at any stage in the product development process. A DfM analysis is available with every quote. Our diverse group of engineers, designers and builders help you navigate the right process, materials and more for each stage of your product development. From design and prototyping to validation for mass production, we’re here for you. Don’t settle for online CNC machining services. Get the engineering and design expertise you need to make your project a success from Fathom!