Design and Geometrical Analysis on Steel Welded Frame of Mini CNC Milling Machine

Centre of vocational development Politeknik Manufaktur Astra has the objective to contribute to vocational high school (SMK) quality improvement. The target is on CNC machining competency. The CNC milling machine was taken as a development project since most of SMK need it but did not have it. As a machine, it should be safe while crashed due to the student users less experienced. Previously, this machine was built using an aluminum cast. During development, porous on the aluminum cast was found and contribute for machine vibration. By running research and discussion, the welded steel plate for frame and machine specification arose out. It was used as a reference to design CNC machine. The next is making some comparison study among branded machine available in a campus workshop. The objective is to build a mini CNC machine with the closed capacity as branded CNC machine available in the market. After having some iteration, the final design using steel welded frame finally obtained. The next process is ensuring the design by doing finite element analysis with the aid of Autodesk Inventor 2016. This study ran an analysis in two study cases which are on the crashed condition and cutting condition. Analysis result data describes that the frame is safe to withstand the load on both of crashed condition as well as cutting condition. The displacement was still on acceptable tolerance. The machine accurate is 0.05 mm under maximum cutting force as 35 N. Though the objectives completed, this study still needs further discussion and experiments to meets another objective completely.