Development of Additive Printing System Using Slant Direct-Drive Parallel Mechanism

Additive manufacturing (AM) technology is extensively applied in various industries, including manufacturing, and is constantly advancing. Compared with subtractive manufacturing methods such as cutting or grinding, the AM is a cost-effective technique with minimal material wastage, and it can produce intricate shapes within a short timeframe. However, research on AM methods involving additional modeling or printing on the surfaces of three-dimensional objects is insufficient. By employing additive modeling, a diverse range of colors and materials can be utilized without requiring support structures, thereby expanding the possibilities of layering-based expression. This study experimentally investigated additive printing systems using a six-degree-of-freedom parallel mechanism stage and a fixed material extrusion head. A slant direct-drive parallel mechanism for a prototype additive printing system was proposed and designed. The developed prototype system enables additional modeling on curved and spherical surfaces of three-dimensional objects. An experimental surface modeling on these objects was conducted. This paper reports on the performance of the motion mechanism, motion range, and positioning accuracy of the modeling stage. Furthermore, the fabricated models were experimentally examined and validated to assess the results of the modeling process.