Keigo Takasugi

Development of Four-Axis 3D Printer with Fused Deposition Modeling Technology

A new four-axis 3D printer using fused-deposition modeling (FDM) technology has been developed. The hardware components, consisting of a mechanical structure and servo-control system, and an original computer-aided machining (CAM) system were developed. Three-dimensional printers, particularly those using FDM technology, have gained popularity even in hobby use for the easy modeling of special and original parts. Three-axis control systems using stepping motors or servomotors are generally used for the development of conventional 3D printers. The nozzle portion is therefore constrained in one direction. This leads to limitations in modeling 3D shapes. Adding degrees of freedom is necessary to create more complex features. We designed a new 3D printer with multi-axis control to address this problem. Our final goal is the development of a five-axis 3D printer. We started with a four-Axis 3D printer as a first step. The number of lamination directions is increased from three to four. As conventional CAM systems cannot be used to program the desired lamination for a four-axis 3D printer, a new CAM system using the Kodatuno kernel was developed. The system can determine the nozzle orientation based on the machine tool formulation. This paper reports the developmental background and an overview of the developed machine tool as well as its characteristics, its evaluation results, and our future plans.

Development of Tactile Globe for the Visually Impaired (Automation of Marking Using an Industrial Robot)

In spite of the importance of the globe as an educational and cultural tool, for visually impaired users, common globes are just spherical objects. Although there are commercially available globes for visually impaired users, globes that have convex and concave features on the surface denoting coastlines and country borders, most of them are expensive because they are made by hand. Consequently, visually impaired users wishing to purchase globes have a very limited range of choices. In terms of industrial production, producing globes with convex and concave surfaces essentially involves machining a spherical surface. For instance, with common machine tools, even positioning or marking a spherical surface of a certain size is very difficult operation since the posture of the tool must change dramatically. The purpose of the study is to develop a CAM system to design the surface of tactile globes suitable for individual needs and to manufacture them for the visually impaired at low cost and with a short lead time. In the report, as the first step, a method of holding the sphere and marking it via 3DCAD/CAM technology and the control technology of an industrial robot is proposed. As a result, the system enables the marking of the coastlines and country borders on spheres automatically using our own CAM system and an industrial robot.

Development of a tandem-table-type CNC lathe with four-axis synchronized control

In the present study, we describe a newly developed CNC lathe for realizing non-axisymmetric curved-surface-turning (NACS-turning). The newly developed lathe can be controlled along four axes (X1, X2, Z, and C) and has a three-linear-motor drive system for the X1, X2, and Z axes to control precise, high-speed motion. The tandem table unit, which moves along the X1 and X2 axes, can move at a maximum acceleration of 98.1 m/s2 synchronously with the spindle rotational position. Therefore, in order to realize high-speed cutting motion of a machining curved surface as well as suppress the vibration transmission, the inertial forces are made to cancel each other. In the present study, the fundamental dynamic performance and vibration suppression effects of the tandem table were examined.

Study on Acoustic Analysis of a Glass Window by BEM and FEM

This research employed acoustic analysis software and established an analytical method for sound transmission loss, which is a sound-insulation performance measure for glass windows. In addition to prediction of transmission loss through vibration of the glass, the research estimated acoustic characteristics that considered transmission loss in the vibration of the frame. Acoustic analysis was conducted with 3D CAD for glass windows of 8 mm plate thickness through preparation of an analysis model under the same conditions as a vibration test. The acoustic analysis also considered both the glass pane and aluminum frame on the side of the sound source. This paper evaluated the results based on analytical values and experimentally observed values.Copyright

Development of CAM System for 3D Surface Machining With CNC Lathe (Tool Path Generation Considering Acceleration)

This study developed a method called non-axisymmetric curved surface turning (NACS-Turning) for a CNC lathe composed of a turning axis and two translation axes. The NACS-Turning method controls the three axes synchronously. This new machining method can reduce the lead time for non-circular shapes such as cam profiles or pistons for internal combustion engines. In our previous report, we presented an outline of a machining principle and a CAM system for NACS-Turning. However, at the same time, we found the problem that the X-axis slide exceeds the allowable acceleration. Therefore, it is preferable that the acceleration is verified during the cam application, and the tool path is generated within the allowable acceleration range. Therefore, this paper first describes the determination method of machinable conditions for NACS-Turning in the cam application. Next, based on the result, relationships between the acceleration of the X-axis slide and machining conditions are clarified. Finally, the experimental procedure showed that our proposed method does not exceed the allowable acceleration of the X-axis slide.© 2014 ASME