Toward Support-free 3D Printing: A Skeletal Approach for Partitioning Models

Area of Science:

• Computational geometry
• Additive manufacturing
• Computer-aided design

Background:

• Minimizing support structures in 3D printing reduces material waste and fabrication time.
• Existing algorithms primarily address support-free fabrication for solid models, neglecting hollowed (shell) models.
• Partitions inevitably introduce seams and cracks, impacting the final product's aesthetics and structural integrity.

Purpose of the Study:

• To develop a skeleton-based algorithm for partitioning 3D surface models into the minimum number of parts for support-free 3D printing.
• To optimize partitions by minimizing the number of parts and total cut length while adhering to support-free printing angle constraints.
• To specifically address the challenge of support-free fabrication for shell models, with applicability to solid models.

Main Methods:

• A skeleton-based partitioning algorithm is proposed for 3D surface models.
• An optimization system is developed to minimize partition count and cut length under support-free constraints.
• The NP-hard nature of the optimization problem is proven, and a stochastic method is employed for optimal solutions.
• A polynomial-time algorithm is presented for a specific case with bounded skeleton graph properties.

Main Results:

• The proposed algorithm effectively partitions 3D models for support-free printing.
• The optimization system successfully balances minimizing partitions and cut lengths.
• Experimental evaluation on various 3D models and 3D printing tests validate the method's efficacy.
• The approach is particularly effective for shell models, offering significant advantages over existing methods.

Conclusions:

• The developed skeleton-based partitioning algorithm enables efficient, support-free 3D printing of shell models.
• The optimization strategy minimizes aesthetic and structural defects caused by partitions.
• This method offers a significant advancement in additive manufacturing for complex geometries, reducing waste and improving quality.