Cost-effective strategies for multi-layer height detection in LWDED

This research explores cost-effective methods for layer height detection in metal additive manufacturing (AM), particularly focusing on laser wire direct energy deposition (LWDED). Despite LWDED's potential, consistent layer height remains a challenge, impacting the quality and tolerance of printed parts. The study reviews various approaches from optical measurements to machine vision systems, addressing their effectiveness and limitations. Further, it proposes and tests two low-cost solutions such as laser distance sensor and a horizontal camera with contour detection, highlighting their strengths and drawbacks in practical 3D printing scenarios. The advantages of the laser distance sensor in measuring wall height directly without complex image processing was offset by its measurement sensitivity to material reflectivity, and manual positioning requirements. Meanwhile, the horizontal camera with contour detection was less demanding in positioning requirements using the contour mean or median z-positioning while offering a more comprehensive measurement than single point measurements albeit being sensitive to the background. These findings aim to contribute to enhance the precision and efficiency of 3D printing technologies, aiming to improve their accessibility and reliability.