Low clearance hinge design improves precision in 3d printed sheet robots
Low Clearance Hinge Joint Mechanism Based on 3D Printing on Sheet Fabrication Methodology
Robotics
Summary
Making strong, precise hinges in sheet-based robots can be tricky because usual methods use glue, which complicates building. The authors studied different hinge types and picked one that works well with very little gap (clearance). They tested how much force the hinge can handle while still moving smoothly. Using this design, they built a small robot arm that moves accurately without the problems caused by extra space in the hinges.
What this means in practice
- •For robot designers: Create compact and precise hinged joints for robots made from 3D-printed sheets without needing adhesives.
- •For mechanical engineers: Build low-clearance hinge mechanisms that maintain strength and reduce unwanted motion in small-scale robotic assemblies.
Authors
Jaehyung Jang, Euibin Shin, Allison M. Okamura, Jee-Hwan Ryu
Abstract
This paper presents a low-clearance hinge joint mechanism based on the 3D printing on sheet fabrication method. This approach simplifies the fabrication of hinge mechanisms and overcomes limitations of conventional origami manufacturing by eliminating the need for adhesives commonly used during assembly, making it suitable for robots at the tens-of-centimeters scale. The advantages and disadvantages of three types of hinge joint mechanisms are compared, and a hinge joint that can be designed with low clearance for various facet thicknesses is selected. Based on the selected hinge joint, the twisting angle and bending force are analyzed, leading to the implementation of a clearance of 0.1 mm. Torsional resistance is experimentally evaluated to measure the torque required for twisting caused by plastic deformation and clearance. The results show that the torque associated with plastic deformation is sufficient to constrain the undesired degrees of freedom of the hinge joint, while the torque required for twisting due to clearance is minimal. Based on the analyzed data, the proposed hinge joint mechanism is applied to a 3-degree-of-freedom delta robot manipulator, demonstrating precise motion with low clearance.