| Automation in production of 3D printed parts, hybrid additive and subtractive machines, and post-processing of 3D printed parts are rapidly growing fields. Given the numerous advancements in the 3D printing industry as reported in this thesis, the lack of availability of a Do It Yourself (DIY) and low-cost hybrid additive and subtractive unit is identified and tackled. This thesis covers the mechanical design of a low-cost DIY, hybrid additive and subtractive unit using a robot arm to remove the 3D printing support structures. Since the removal of printed support structures has not been investigated in the scientific literature, in a first step, different cutting tools and speeds were analyzed with a hand-held Dremel 4000 power tool with regard to cut quality and cutting forces. An off-the-shelf tool bit, a High-Speed steel cutter, at 15000 rpm yielded the best results. Furthermore, a hybrid machine was conceptualized, consisting of additive and subtractive subsystems. The constraints are a working volume of 6 cubic inches and costs below $5000. The additive system is based on following components: X, Y and Z Motor Holders, Filament Holder, and 3D Printing Arm, which can be printed by the DIY user, and off-the-shelf hardware like NEMA 17 stepper motors. The subtractive system is based on the following components: Motor Holder, Linkbot Mounting Interface, and Connector Arm, which are also designed to be 3D printed by the DIY users. For both subsystems, the off-the-shelf parts are specified, and technical drawings for 3D printing and assembly are provided. The critical 3D printed parts are analyzed with regard to their maximum distortion and strength during operation. |
