CNC Grinding vs Spark Erosion Grinding: What Are The Differences?

While computer numerical control (CNC) grinding and spark erosion grinding have similarities, they achieve results in different ways. These two subtractive processes both remove material from a solid block to grind the workpiece into a desired shape. The method used for grinding differentiates the two processes.  

What is CNC Grinding?

CNC grinding uses a computer-controlled rotating wheel to cut away metal and provide precision finishing. While frequently used for cylindrical pieces, it is not limited to this shape. The CNC machining process is popular for creating ball bearings, transmission shafts, valves, camshafts, and other components that require adherence to strict tolerances and flawless finishes. 

There are multiple types of CNC grinders, including:

•   Crankshaft grinders
•   Plain cylindrical grinders
•   Roll grinders
•   Surface grinders

Computer numerical control mitigates the risk of human error. Once a technician enters the specifications for the part into the machine, a program then guides the grinding operation to create an extremely precise part with a perfect finish. Automated robotics can load or unload the workpiece, reducing labor needs and allowing for around-the-clock operation.

These unmanned operations require only intermittent observation to ensure that the machine is working correctly. Reducing the need for manual intervention increases precision, worker safety, and cycle time during the manufacturing process.

What is Spark Erosion Grinding?

Also known as “honeycomb grinding,” spark erosion grinding is another subtractive machining process that uses an electrode rather than a rotating wheel to form and finish the part. Whereas CNC grinding cuts away excess material from the block, spark erosion disintegrates the material using an electric arc. For this reason, spark erosion grinding only works with electrically conductive materials.

Spark erosion grinding may be referred to by various names, such as:

• Electrical discharge machining (EDM)
• Spark eroding
• Burning
• Die sinking
• Wire burning
• Wire erosion

When hard metals need to be shaped into intricately shaped pieces, electrical discharge machining is often the best process. Many industries use spark erosion grinding, including oil and gas, aerospace, nuclear energy, and industrial manufacturing. EDM creates a shape without touching the metal, making it useful for machining delicate workpieces. 

The process begins by drenching the workpiece in a dielectric liquid before mounting it on a lathe or turning center. The lathe secures and rotates the metal, and a hydraulic or electronic mechanism moves the electrode close to the workpiece. As it gets close enough, a spark from the electrical discharge jumps to the part, creating a hot plasma that vaporizes the dielectric liquid and melts away the metal in a very controlled and precise manner. 

Spark Erosion Grinding Services from Union Machine

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Traditional CNC grinding is a valuable tool for machining precision parts with a high-quality, flawless finish. For hard and electrically conductive metals, however, spark erosion grinding can provide precise and intricate details.

At Union Machine, we can help you determine the best machining process for your application. Our company is an original equipment manufacturer and prime contractor for the aerospace industry. For over 60 years, we have been providing jet engine components and other precision parts from our AS9100D- and ISO:2015-certified facility. We offer cost-effective, burr-free grinding with a variety of alloys, metals, and engineered plastics. 

To learn more about how we can help you with your machining needs, contact us today. 

Benefits of 5-Axis Laser Cutting

While 3-axis laser cutting has become relatively common in recent years, advances in laser cutting equipment have led to the development of 5-axis laser cutters. This is the preferred process for 3D laser cutting, as it enables the rapid, easily repeatable manufacture of complex components by cutting along these five axes:

• X-axis (left to right)
• Y-axis (forward and backward)
• Z-axis  (up and down)
• A-axis (rotational)
• B-axis  (tilted)

The addition of the A and B axes makes it possible to machine parts from virtually any angle with a greater level of precision. Common items machined with 5-axis laser cutting include:

• Blades
• Wheels
• Curved, circular, or cylindrical parts
• Parts requiring angular cuts

5 Axis Laser Cutting vs. 3 Axis Laser Cutting

The 3-axis laser cutting process functions solely on the X, Y, and Z axes, without allowing tilting or rotating of the table. This limitation means that the user must frequently readjust the part to complete the cutting process. Multiple setups are time consuming, increase the risk of error, and may reduce the precision of the machinery. With each additional setup, the alignment of the part is unavoidably impaired.

Additionally, a limited number of axes makes it challenging to machine complex three-dimensional parts. Instead, 3-axis laser cutting is a more suitable choice for smaller, simpler components. 5-axis laser cutting enables the rotation and tilt of the table, making it possible to produce complex parts efficiently and accurately. For larger three-dimensional parts or complex designs, 5-axis laser cutting is the optimal choice.

The Benefits of 5-Axis Laser Cutting

5-axis laser cutting has several significant advantages:

Single Setup

In contrast to 3-axis laser cutting, 5-axis laser cutting will often require a single setup. This allows for the efficient and accurate machining of complex parts, greatly improving efficiency and reducing the number of potential mistakes.

Angular Holes

5-axis machining also has an advantage when it comes to drilling angular holes. While 3-axis laser cutting requires multiple setups for every hole, the tilting and rotating abilities of 5-axis laser cutting make it possible to drill multiple holes from different angles without ever removing the component. This increases accuracy and makes for a more timely production process.

Complex Parts

Each of these benefits contributes to what is perhaps the biggest strength of 5-axis laser cutting: the ability to efficiently machine complex, high-quality parts. This process is easily repeatable. After the machine has been programmed once, no more effort is required to create an identical run of components.

How 3D Laser Cutting Works

The 3D laser cutting process focuses a highly coherent beam of light on the workpiece. In order to shape the part to the desired specifications, the laser will melt, burn, or vaporize the unwanted material. As laser cutting only impacts a small portion of the material, it is able to create parts with minimal warping.

5-Axis Laser Cutting at Union Machine

At Union Machine, we are AS9100D, NADCAP, and ISO 9001:2015 certified, and our skilled team is standing by to assist with your next project. For more information regarding how Union Machine can help with your 5-axis laser cutting needs, feel free to contact us today!