Milling Center for Micro Machining

Milling a Jewelry Ring

The machining center for micro-machining enables milling with very small and filigree tools. The high-frequency machining spindle and the precise and stable design of the milling center ensure process-reliable machining even with small tools. Using the example of a jewelry ring, we would like to explain the application of micro-machining (the micro-milling). 

cnc milling center for micro milling or micro machining

Conditions of Micro Machining

CNC milling center for micro machining

ENGRAVER

CAM-Software

Fusion 360

Clamping device

Three-jaw chuck with brass jaws

Workpiece material

Silver

Cooling / Lubrication

Minimum quantity lubrication, cooling by air and spray mist

Tools

End mill Ø0.6mm, Ø0.4mm, Ø0.25mm

Model of the Ring for Micro Milling

At the beginning of the micro milling with the CNC machining center, the model of the ring is designed. This can be created using any CAD program or Fusion 360. Of course, external CAD models can also be imported, e.g. as Step files, SolidWorks files or Rhino files. We create a cross-sectional sketch for the jewelry ring, which is then extruded around the center axis. We then draw in additional sketches as sections of the microcut. These sketch profiles are stamped into the surface of the ring at the end. 

ring model for micro milling
design ring model for the milling center micro machining
drawing ring model for machining center

Toolpaths for Micro Machining with Milling Center

After the ring model has been completed, the toolpaths for microcutting can now be created. On this page, we use the Fusion 360 CAM environment for this. Of course, our machining center can also work with other CAM programs. Please contact us for more information.

To create the toolpaths, we switch to the Fusion manufacturing environment. There, the setup for micromilling is set first. We set the workpiece coordinate system and define the blank. To simplify the creation of the toolpaths, the spaces between the ring arcs are suppressed. This means that the gaps can be milled using the pocket machining method.

setting the setup for milling center

Once the micro-machining setup is defined, the individual tool operations can be added. The first machining operation is 2D pocket milling inside the arc profile of the jewelry ring. To do this, start the machining operation in Fusion and select the corresponding machining surfaces. Then you select a machining tool for the operation. For the microcutting of the first operation, a Ø0.6mm end mill is used. In Fusion and CamDRAW, all tools are stored in a tool library. All cutting data, geometries and properties can be stored for each tool. Included with our CNC machining center for micro cutting are tool libraries for a very large number of milling and engraving tools that can be used for micro milling. These tool libraries include all common milling and engraving tools.

first operation of micromachining

The next operation is micromilling between the individual arc segments. The procedure is identical to the first operation, except that a different tool is selected. A Ø0.4mm end mill is used.

second operation for cnc machining center micromilling

The final machining operation is contour milling on the walls of the micro-milled pockets. This is used to reduce and remove the radii in the corners of the pockets. Since the pocket machining operations were performed with larger tools, small radii remain in the corners due to the process. These are now reduced with a small end mill of Ø0.25mm to such an extent that they are no longer visible to the naked eye. The total number of operations required is three. Now machining is almost ready for milling with the machining center for microcutting. 

third operation 2d contour milling with the micro machining center

Simulation of the tools for safe micromilling

Optionally, you can simulate the entire machining process in Fusion. To do this, simply click on the setup and select Simulation. In the simulation, collisions or other errors are detected and reported very well.

simulation of the cnc program for milling center
micromilling second simulation

Create CNC program for the milling center for microcutting

The last step is to create a new CNC program in Fusion. This is needed to output the machine code ( G-Code) for the machine. Here only the correct postprocessor for the milling center ENGRAVER is selected. The output can start. All necessary postprocessors for the ENGRAVER are included with the machine. If you work with another CAM software, a suitable postprocessor for our machine can be created for this with pleasure.

Summary of micromilling with the machining center