Discussing Challenges in Large vs. Small Part CNC Machining

CNC machining is a subtractive manufacturing process that uses computer numeric control to create objects from metal, plastic, and other materials. The technique helps create parts from two-dimensional or three-dimensional computer models. The process begins with a Computer Aided Design (CAD) drawing which is then processed into a format that the machine can understand. A CAM software is then used to create the specific tool paths that will be used by the CNC machine to fabricate the part.

In almost any manufacturing or machining environment, there will be a time when an extremely large or small part needs to be made. This may be challenging to accomplish with traditional machines. When this happens, CNC machining can be used to create the part. CNC machining is often the best choice for small and large parts machining because it offers many advantages over other manufacturing methods. Being said this, there are several challenges involved in small and large part machining, which are discussed in this post.

Challenges in Small Part CNC Machining

Small part machining is a process that is often used in the manufacturing industry to produce small parts with intricate details. This process can be challenging because it requires a high degree of precision and accuracy. In addition, there are a number of factors that can affect the outcome of the machining process, including the type of material being machined, the machine settings, and the environmental conditions. Major challenges in small part CNC machining include;

• Difficulty in Achieving Tight Tolerances: One of the major challenges in small part CNC machining is that it can be difficult to create complex shapes and designs with tight tolerances. As a result, certain elements of the design must often be simplified or eliminated altogether.
• Material Damage: When small parts are machined using standard CNC equipment, the cutter can cause thermal and mechanical damage to the material. This is generally not a problem for larger parts, but when reducing the size of a part, these issues become more apparent. The smaller size of the part means that there is less material surrounding the cut area, leading to high temperatures and higher chances of damage.
• Difficult to Chamfer: Chamfering is a machining process employed to produce smooth, round edges on square or rectangular corners. The process can be performed on a lathe, milling machine, or grinding wheel. The goal of chamfering is to create a relieved surface that will reduce the stress concentration at the sharp corner. Chamfering is often used during the manufacturing of small parts, where the reduction in size and weight can be critical to success. Due to small size and intricate detailing on many small parts, even the slightest misalignment can lead to imperfect chamfer.
• Difficult to Debur: Deburring is a machining process that is used to remove any burrs or sharp edges on the surface of a part. This is often a necessary step in the finishing process, as burrs can create problems during subsequent operations or even cause injuries if they are not removed. Deburring can be a difficult process, especially when dealing with small parts. In order to achieve the best results, it is important to use the right tooling and to take the time to properly adjust the machine parameters.
• Drilling of Deep Holes: One of the challenges that CNC machine operators face is drilling deep holes. Drilling deep holes can be difficult because the bit can easily wander off course, and it can be difficult to maintain the correct angle and depth when drilling deep holes. When a hole gets too deep, the drill has a tendency to break or spiral. This is a common problem for small parts with tight tolerances.

Challenges in Large Part CNC Machining

Large part CNC machining occurs when a manufacturer produces a component or product that is much larger than what can be produced using traditional machining methods. Often times this means that the component must be broken down into smaller parts, which are then machined and assembled. Major challenges in large part CNC machining can be summed up below:

• Too Much Heat Generation: No material is without its limitations, and with the ever-growing demand for stronger, lighter, and more complex parts, materials scientists are constantly working to find the best new alloys and composites. Inevitably, as these materials are pushed to their limits, flaws will begin to appear. In a recent study, it has been found that the heat generated during the large part CNC machining process can have a significant impact on the overall quality of the finished product.
• Stress: When machining large parts, the CNC operator has a propensity to introduce stress on the workpiece. The larger the part, the more challenging it becomes to maintain its geometric accuracy during machining. Consequently, as parts become larger, operators tend to take shortcuts in terms of part holding and fixturing in order to reduce cycle time and maximize throughput. While these shortcuts may lead to an increase in productivity, they also invariably lead to increased levels of stress and distortion within the workpiece.
• Additional Set Up: When machining large parts, an additional set up is often required to ensure that the part can be machined successfully. This set up typically includes a fixture or jig that secures the part in place and a tooling system that allows the cutter to reach all the necessary areas. Another thing that needs to be done is to use a higher spindle speed when machining large parts. This will help to reduce the cycle time and make the process more efficient. Finally, the toolpaths need to be carefully planned so that the machine can move around the part without hitting any obstacles.
• Difficulty to Inspect: Inspecting large CNC machined parts can be challenging. There are many planes and surfaces to check for defects, and it can be difficult to know where to start. With the increase in size of the parts, it has become difficult to identify any defects or errors on the surfaces of the parts. The traditional methods of visual inspection and measurement are not feasible anymore and new methods need to be developed for this purpose. This is a major challenge for the manufacturers as it can lead to defective products reaching the customers.

Considering all the aforementioned challenges, it is important to deal with a machinist who can handle any challenge that comes up during the small and large parts machining process. By working with an experienced and knowledgeable partner, you can avoid common mistakes, save time and money, and ensure that your parts are produced to the highest standards. This post ends by letting you know about such a trusted manufacturer – Brogan & Patrick – who offers small and large parts CNC machining services. They are ISO certified and have been in the business for several years. With their precision equipment and experienced team, they are capable of producing high-quality parts for various industries.