Improved quality and shortened times to design and manufacture injection molds

Mimar Group from Grosuplje in Slovenia manufactures plastic parts, primarily through injection molding. Parts are mostly small in size and volume, and produced in variety of materials. They were experiencing challenges during mold design and preparation for CNC machining. As input models were quite often in STL format or based on linearly interpolated curves in DXF format, they had difficulties producing finished mold surface in desired quality. Limited choice of traditional milling and boring strategies led to long machining times and frequent breakages of finer, small size machining tools.

The main goal was to improve the quality of final product while shortening time to production. "Mimar Group" was looking for a partner to help them implement CAM process which would improve the quality of finished mold surface and eliminate the need to deal with imperfections. The solution should support a broader choice of input formats and enable them to prepare the models for additional manufacturing methods (mold machining, EDM, additive technologies). They were unwilling to invest in complex or expensive solutions and wanted the proof of benefit as early as possible.

Implemented solution is based on Autodesk Fusion 360. It supports import of variety of 3D formats, provides environment to alter the models, add or remove features and prepare them for CNC machining or 3D printing. Numerous strategies for rapid removal of material (like Adaptive Clearing), or final surface finishing (like Scallop, Contour, Morph, Pencil and Flow) simplify toolpath generation and shorten the machining time, while increasing the quality of finished mold surface. Smoothing option helped them produce the optimal toolpaths and dramatically reduce the number of lines of G-code which posed the problem for machine control in the past.

In order to shorten the time to desired results, implementation and adoption of best practices were facilitated by training and consulting services provided by "PRIOR inženjering", Autodesk Gold Partner.

Although post processor customization is often part of implementation, in this case it was not necessary as the CNC machine "Mimar Group" owns is well supported by stock post processors from Fusion 360 library.

Significant and measurable improvements were achieved immediately after the implementation of Fusion 360. Typical machined mold was used as a test case to measure the impact. It was previously machined using traditional methods in 4 hours and 15 minutes. Applying the new process based on Fusion 360 and using 3D Adaptive Clearing for roughing and Scallop, Contour and Pencil for finishing resulted in milling the same mold in 1 hour and 15 minutes or 3.4 times faster. Besides, quality of finished surface was much better and beyond anything previously achieved using traditional methods.

Autodesk Fusion 360 is tried and true solution for all sorts of machining tasks. Large library of free post processors eliminates the need for customization in many cases like in this one, while consulting, implementation and training services ensure shorter path to desired outcomes.

After initial success with reaching the project goals, "Mimar Group" is considering further improvements of their workflows. The next goal is to improve results with complex surfaces using Steep & Shallow strategy from the Fusion 360 Machining Extension and after that complex patterns design with Product Design Extension.