Advantages Of CNC Rapid Prototype Proofing

When manufacturers require fast delivery, they hope to deliver a delivery that meets the manufacturing design specifications within one or two days. Prototypes have complete functions, forms and surface treatments, so customers can experiment with designs, improve functions, check surface treatments, and evaluate different materials.

Production quantities can consist of one to thousands of units, so choosing a production method that can provide the quantity and quality you are looking for is crucial. Computer numerical control (CNC) machining combines the accuracy, precision, repeatability, and scalability required to produce high-quality, prototypes. It will meet your strict tolerance requirements and achieve various finishes. Of course, the shortcomings also exist. The advantages and disadvantages of CNC machining are detailed below to consider your rapid prototyping needs.


Advantages and disadvantages of CNC machining fast prototype proofing

Whether your product requires milling, tapping, grinding or drilling, CNC machining can provide a variety of advantages for your product.

1. Benefits

1) Precision and tolerance
When manufacturing parts, you want the final size to match the size specified in the CAD file as much as possible. Accuracy is produced in manufacturing through the consistency and repeatability of the machine process. CNC machining provides high accuracy by consistently reproducing the correct measurements of all values of the machined part.

Accuracy also defines tolerances—the allowable deviation of the measurement system from known or standard values. Tolerances appear in the form of positive and negative (+/-) factors, specifying the amount of deviation from a known value. Specifying tolerances allows flexibility in manufacturing methods and ultimately saves time and money in part production. During operation, the sensor in the CNC machine tool provides feedback data for each axis to ensure that the machining measurement value is close to the specified value.

CNC machining provides tighter tolerances than other prototype production methods. Stereolithography and industrial FDM 3D printing produce tolerances of +/-0.3mm and +/-0.5mm, respectively. Depending on the type of metal and the design of the part, CNC milling and turning can produce tolerances between +/-0.025mm and +/-0.125mm.


2) Repeatability
CNC machine tools have the advantage of repeating precise and accurate tool movements throughout the production run, because the programming code controls all functions. Repeatability occurs when the machine moves to the target point multiple times with the smallest distance difference.

As with any machining technology, repeatability measurement also depends on other factors, such as tool wear, CNC machine tool life, workpiece material and machine settings. Advanced software can be used to monitor this information with minimal mechanic intervention.

3) Material
Compared with the limited range of materials used for 3D printing, CNC machining provides the advantage of using a variety of materials, including various aluminum and stainless steel alloys, plastics, copper, brass, bronze, and more. CNC machining also provides the use of certifiable materials that meet different needs, such as hardness, tensile strength, durability, and wear resistance.

Tensile strength represents the ability of a material to resist fracture under tension, while endurance strength represents the ability to absorb stress. Wear resistance refers to the ability of a material to withstand friction or self-lubricating.

Depending on the application, rapid conversion prototypes may require lightweight materials to keep the weight of the prototype within design standards, or heavy materials that can withstand high stress loads. Others require that the material does not melt, warp, swell or deteriorate at working temperature.

4) Finish
In some cases, you will specify a specific surface finish for the prototype. Alternatively, you can specify the parameters that affect the surface texture, such as average roughness or the vertical distance from the top of the irregular peak to the bottom of the valley.

CNC machining is superior to other manufacturing methods because engineers can choose from a range of custom finishes that meet design requirements. For example, rotating shafts may require fine surface textures, while load-bearing surfaces can use rough or "milled" surfaces, which can reduce cost and turnaround time.

5) Scalability
CNC machining is more effective in scale than other prototyping methods (such as 3D printing). It can process uniform parts repeatedly and accurately, thereby seamlessly increasing output.

In some cases, rapid production of large numbers of prototype parts is limited to machining. For example, if you need 10,000 precision parts made of stainless steel, CNC machining is the best if not the only option.

CNC machining can replicate express prototypes with higher precision and tolerances (and customized surface treatments) in almost any type of material. Ultimately, it enables you to bring potentially more valuable products to market faster.