Proposal of 3D Printed Parts Joining Method for Larger Size

In recent years, it has been expected that conventional parts used in industrial robots can be replaced with 3D printed materials to reduce weight and improve performance.However, it is not easy to produce large parts in one piece using a 3D printer.This is due to the problem of thermal shrinkage and the fact that the size of the part depends on the bed size of the 3D printer.Therefore, it would be highly versatile if small parts could be joined easily and without loss of strength to form large parts.We proposed a new joining method by mating and bonding square pyramidal concavo-convex parts, and evaluated its strength by three-point bending tests.As a result, strength of about 140% was obtained compared to bulk materials of the same size.Comparisons were also made with different shapes and materials to demonstrate the effectiveness of the proposed joining method.