By Matthias Leinberger
Our steering knuckle was carefully designed and optimized for weight, durability, and manufacturability. The next critical step was to guarantee flawless quality control for our industrialized process. Joe, our devoted Orlando-based part quality engineer, took on the crucial responsibility of managing and programming our CNC machines, which is an essential part of quality control.
We made use of NX’s PMI (Product and Manufacturing Information) features from the beginning of the design process. To ensure that the tolerance and dimensions data applied to the model were both syntactically and semantically acceptable, the design team employed PMI Advisor. Geometric and dimensional tolerancing (GD&T) is a difficult subject but a crucial stage in the part manufacturing process that PMI Advisor assists the user with. The team had trust that the data applied to the model complied with pertinent industry standards and was able to handle complexity with ease thanks to this application.
The non-geometric qualities needed for the manufacturing of product assemblies and components are stored in product and manufacturing data. In addition, PMI can contain surface finishes, material specifications, geometric dimensions and tolerances, and 3D annotations (text and dimensions). As a component of the model-based defining technique, PMI is integrated into the 3D model. Several downstream processes can then use this information, doing away with the need for drawings and automating the process. For instance, NX CAM and NX CMM have direct access to PMI, enabling programming automation.
Traditionally, a drawing contains the tolerance information needed for manufacturing. But in the digital machine shop setting, this data is contributed as PMI during the design phase to the digital twin of the 3D part model (a model-based design and manufacturing technique). This ensures that the most recent version of the design and manufacturing process is available in all cases. Additionally, notes that are usually drawn in pencil on paper can be added as PMIs to the model. This implies that you can edit and turn the final paper drawing into a final as-is drawing without having to return it to the designer. Without further interpretation, all critical-to-quality tolerances can be consumed immediately in the CMM environment.
Using the PMI added during the design phase, NX CMM automates the generation of inspection features, tolerances, and routes. This can be done with only one click. Joe will have all the tools necessary to describe the entire inspection process that he will execute on the CMM machine thanks to NX CMM’s vast selection of inspection path types, which include points, scan lines, scan curves, scan arcs, and full 5-axis curve scanning. This guarantees faster programming and accurate and efficient machine-based part inspection, regardless of the feature control frames or linear tolerances.
The fact that NX CMM organizes all of this inspection-related data into a single file that can be consumed straight into the quality environment is significant. This lowers the likelihood of errors occurring when the CMM programmer has to manually enter data and interpret drawings.
Joe had to make sure that any potential accidents on the shop floor would not happen, such as collisions with obstructions on other people’s machines, on the inspection path. Joe used machine code simulation on a digital twin of the CMM to verify everything in order to do this.
Joe transmitted the component inspection program to the machine, executed the inspection using a fully verified CMM inspection program, and then imported the results back into NX CAM to compare the real results with the nominal part model. Joe assessed “as-built” measurements in conjunction with “as-designed” models by utilizing the data analysis capabilities of NX CMM, which allowed for efficient quality improvements. NX’s integration of CMM measurements allows for a thorough comparison to related tolerances based on ISO, ASME, or ANSI standards.
The nominal comparison offered a visual representation of the features that passed, failed, and may need to be revised. When we met an out-of-tolerance situation, this was incredibly helpful. Upon investigation, it was found that the knuckle arm that uses a ball joint to connect to the outer tie rod was out of tolerance and still had some residual tension.
Joe, the CNC programmer, and Adam, the additive manufacturing expert, may work together to decide the best course of action for handling the out-of-tolerance scenario because NX CMM is a component of an integrated digital machine shop environment.They were allowed to temporarily relax the tolerance on this particular feature because the arm was attached to a ball joint and would eventually require alignment. They will now focus on improving the heat treatment procedure to address this issue. This update would be available in all product and process data, preserving associativity and traceability, just like any other future design modification. The remaining features were all in tolerance, according to the NX CMM data analysis. After that, we might authorize the item to be assembled on the eRod and carry out the last test procedures in an actual setting.
NX CMM Inspection Programming guarantees a quick response to design changes, saves costly CMM machines, and cuts down on programming time. In conclusion, the digital twin transforms quality control in the digital machine shop enabling us to:
- Program automatically, utilizing solid model PMI attachments.
- Use machine simulation to verify programs.
- Measure fast using high-speed inspection techniques.
- Examine the measured data and compare it to the master model’s design as it was intended.
Every component requirement is examined in accordance with business guidelines, and quick and effective design change propagation throughout the process is provided. Real-time updates and smooth integration are made feasible by a single CAD, CAM, and CMM system. Without requiring imports or exports, this system facilitates collaboration, optimizes workflows, and enables rapid and effective comparisons between the “as-built” and “as-designed” states since everything is easily accessible in a single, well-managed environment.
In our upcoming blog, we will get into the actual CNC machining process and speak with Chris Pollack about how he used a lathe machine fitted with a Sinumerik controller to make the wheel knuckle spindle.
