Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

Kerf-Taper-Angle Control and Additive Process for Formwork Laser Cutters

Sol Chai, Chanwoo Kim, Yeonho Ko and Daehie Honga

Mechanical Engineering, Korea University, Republic of Korea


EPS (Expanded Polystyrene) formwork is used to construct freeform buildings. Freeform EPS formwork is usually made by CNC milling process, which is quite expensive. The problems of the milling process for EPS Formwork can be summarized into two factors: limitation of scale, long manufacturing time. Various studies are conducted to overcome these problems. In particular, the combination of laser cutting and additive processes can effectively solve these problems. Because laser cutting is a non-contact cutting method, it is free from the limitations of scale, and rapid production is possible through the additive process. However, when laser cutting is performed, a kerf taper angle is generated inevitably. The kerf taper angle means the cutting angle that occurs as the cut surface is formed into a trapezoidal shape by laser divergence. Due to the characteristics of the additive process using a thick plate, it has a fatal effect on the quality of the result as a sawtooth-shaped lamination trace. In this paper, a compensation technique was devised to solve this angle. It is a control the vertical angle of the tool’s travel direction so that the laser diverges to the cutting waste. Path generation strategies and application of laser parameters need to be studied. In this paper, the diffusion angle of the laser passing through the lens is calculated using the laser parameters, and a corrected tool path generation strategy is established accordingly. The vector was calculated through Rodrigues rotation and applied to the 5-axis laser. Lastly, the shape that can be made may be limited due to the angular limit of the 5-axis laser. To overcome this, we propose a multi-plane additive manufacturing system. Compared the results with the existing ones to verify the performance improvement. The new construction method was applied to make a formwork, and a freeform bench model was constructed and exhibited.

Keywords: Kerf-taper-angle, multi-plane additive process, Lamination, Laser cutting, Freeform formwork

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