M2 Prototype CNC machining steps

CNC machining is a computer-controlled manufacturing process that involves the precise removal of material to create a desired part. In order to help clients understand how their on-demand  products are perfectly produced, hereby, we introduce M2 Prototype CNC machining steps in details as below.

Design studying

M2 engineers will throughly discuss with client about his design requirements to ensure that the final product meets his expectations. This includes discussing the 3D CAD model, tolerances, surface finishes, and any other specific design features.

CAD-CAM programing for cnc machining

CAM Programming

Convert the CAD model into a set of CNC machine instructions using Computer-Aided Manufacturing (CAM) software. The CAM software generates G-code, which is a programming language used to control CNC machines. This code specifies the tool paths, feed rates, and spindle speeds required to create the part. CAM programming is a crucial step in the CNC machining process, as it translates the 3D CAD model into machine-readable instructions. Here’s a more detailed explanation of the CAM programming process:

• Import CAD Model: Import the 3D CAD model into the CAM software. The software supports various file formats, such as STEP, IGES, or native CAD formats.
• Define Machining Operations: Identify the specific machining operations needed to create the part, such as milling, drilling, or turning. For each operation, specify the cutting tools, tool paths, and cutting parameters.
• Toolpath Generation: The CAM software automatically generates toolpaths based on the defined machining operations and the geometry of the part. Toolpaths are the paths that the cutting tool follows during the machining process. They dictate the sequence of cuts, the depth of each cut, and the direction of the tool’s movement.
• Simulation and Verification: Run a simulation of the machining process within the CAM software to verify the toolpaths and identify potential issues, such as tool collisions, excessive material removal, or inefficient toolpaths. Make any necessary adjustments to the toolpaths or cutting parameters.
• Post-Processing: Once the toolpaths are verified, the CAM software generates the G-code, which is the machine-readable set of instructions that the CNC machine will follow. The G-code is generated through a post-processor, which is a software module that converts the toolpaths into machine-specific code, taking into account the specific capabilities and limitations of the CNC machine being used.
• Transfer G-code to CNC Machine: Transfer the generated G-code to the CNC machine’s control system, either through a direct connection, a USB drive, or another data transfer method. The CNC machine is now ready to execute the G-code instructions and create the desired part.

Material Selection

It is a crucial procedure of CNC machining steps, as it directly impacts the quality, performance, and cost of the final product. This step involves choosing the most suitable material based on the desired properties, application requirements, and budget constraints. Factors to consider during material selection include mechanical properties, machinability, surface finish, dimensional stability, and thermal and chemical resistance.

cnc milling tool selection

Tool Selection

Selecting the right tool for milling is one of the critical CNC machining steps that can impact surface finish, tool life, and machining efficiency. Below are the factors that M2 Prototype engineers always consider to select the right tools.

• Consider the material. Different materials have different properties, such as hardness, toughness, and ductility. These properties affect the cutting forces, heat generation, and chip formation during machining, which in turn determine the selection of the cutting tool.
• Determine the cutting conditions such as the spindle speed, feed rate, and depth of cut, based on the material being machined and the tool paths generated by the CAM software.
• Choose the tool material. Our engineers will choose the appropriate tool material based on the cutting conditions and material being machined. For example, carbide, high-speed steel, and ceramic are commonly used tool materials, each with their own advantages and disadvantages.
• Tool geometry such as the tool diameter, flute length, and helix angle, will be selected by M2 engineers based on the features of the part being machined and the tool paths generated by the CAM software.
• The tool coating can affect the tool life, cutting performance, and surface finish of the machined part. Different coatings, such as TiN, TiCN, and AlTiN, can be used depending on the material being machined and the cutting conditions.
• After selecting the tool, it should be verified for performance by running test cuts on the material being machined. The cutting forces, temperature, and chip formation should be monitored to ensure that the tool is performing as expected.

Workholding

Securely fix the workpiece to the CNC machine’s worktable using clamps, vises, or fixtures. Proper workholding ensures the part remains stable during machining, preventing inaccuracies or damage.

CNC Machine Setup

Load the G-code into the CNC machine’s control system, set the required tools in the tool changer, and establish the work coordinate system by setting the machine’s zero point (work offset). This helps the CNC machine accurately locate the part on the worktable.

Dry Run

Perform a dry run (without cutting) to verify the correctness of the G-code and machine setup. This step helps identify potential collisions or errors before actual machining begins.

Machining

Start the CNC machine, allowing it to follow the programmed G-code instructions to cut the material and create the desired part. The CNC machine’s spindle rotates the cutting tool at high speeds while the machine’s axes move the workpiece according to the specified tool paths.

Monitoring

Continuously monitor the CNC machine during the machining process to ensure it is operating correctly and efficiently. Adjust feed rates, spindle speeds, or tool paths as needed to optimize performance and maintain part quality.

Inspection

After machining is complete, inspect the finished part for accuracy and quality. Use measuring instruments such as calipers, micrometers, coordinate measuring machines (CMM) to verify that the part meets the specified tolerances and dimensions.

Post-Processing

Perform any necessary post-processing operations, such as deburring, polishing, or heat treatment, to achieve the desired surface finish or material properties.

Quality Control

After all the cnc machining processing, M2 QC department will conduct a final quality control inspection to ensure the part meets all design requirements and specifications before it is delivered to the customer or used in assembly.