Everyone intuitively understands that milling machines, holders and tools are difficult to scale down to the microscopic dimensions and extreme accuracy needed for micro-milling. At first glance, software might seem to be an easier fit.

After all, one might claim, working with a number like 0.0001 should be just as easy for the software as working with 1.0 or 10.

But there is more here than meets the eye. Creating and modifying geometry with the right accuracy, smoothness and continuity are just the entry points for a micro-component CAD solution. In order to have a functional solution for micro-milling, the CAD systems must be carefully tuned and optimized to support the following requirements:

Read the part model reliably and accurately. Minimizing the need for multiple data conversions is critical for maintaining accuracy of the detailed model.

Work with tight geometric tolerances of 0.1-0.01 microns when generating parting surfaces or creating geometry for sliders, lifters and ejectors. This is essential in order to prevent gaps between surfaces and to keep C1 and C2 continuity.

Handle multicavity molds of very small sizes, including specialized catalog parts and assemblies.

CAM systems also must be optimized for micro-milling. NC software must handle the tight tolerances and ultra-accurate machining. And since the operator cannot interfere to prevent tool breakage, the NC software must accurately consider the chip load throughout the machining process.

To adequately support micro-milling, the CAM software should be able to:
Accurately utilize the highly detailed mathematical model, while maintaining its level of complexity. Having an integrated CAD/CAM solution is ideal, since it eliminates any data translations in the process.

Include high-accuracy, built-in CAD capabilities within the CAD system that can provide assisting geometry (e.g., capping, extending surfaces, etc.) with the appropriate accuracy and tangency within the CAM system.

Support toolpath calculation with tolerances down to 0.1micron. This is especially challenging when machining miniature details in large size parts.
Support calculation with micro-milling level parameters considering the constraints of the physical machines. For instance, the CAM system may be required to provide super-finish results with a tool diameter of 0.1mm, a side step of 0.005mm and a 10 times large round corner radius of 0.05mm. Toolpaths must be created accurate to the fifth decimal point.
Support machining strategies optimized for micro-milling, such as the machining of rough, re-rough and finish in the same NC operation.

Use the knowledge of actual remaining stock throughout the entire process to adjust feed to actual tool load in order to lower machining time while protecting the delicate tools from breaking.