Heat-Embedded Threaded Sleeve for Stronger FDM Screw Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing screw connections in components manufactured by Fused Deposition Modeling (FDM) process lack strength and stability due to anisotropy in the material structure, leading to potential separation of filament layers and limited reusability.
Innovation Solution
A threaded sleeve with a groove along its longitudinal axis and a self-tapping thread on the outwardly facing surface, combined with a metric thread on the inwardly facing surface, is used with heat input to enhance strength by melting and adhering the filaments to the thread geometry, ensuring a firm connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If self-tapping screws are used to screw directly into FDM components, then assembly is quick and inexpensive, but the screw connection strength is insufficient and layers may separate
Solution Approach 1:
A threaded sleeve is introduced as an intermediary component between the screw and the FDM component. The sleeve is first firmly attached to the component (by heat embedding, adhesive, or integration), providing a strong anchor point. The screw then threads into the sleeve instead of directly into the weak FDM material, transferring loads to the stronger sleeve-component connection and preventing layer separation.
Solution Approach 2:
The solution combines multiple materials with complementary properties: the FDM component (providing structural form), the threaded sleeve (providing mechanical thread engagement and load distribution), and the screw (providing fastening function). This composite approach allows each material to perform its optimal function, achieving both strength and ease of assembly.
2Reliability
If threaded sleeves are inserted by heat embedding, then reusable metric thread connection is achieved, but the insertion process is complex and time-consuming
Solution Approach 1:
The threaded sleeve is designed with self-centering and self-aligning features that allow it to be inserted and secured automatically or with minimal guidance. The sleeve's geometry enables it to find its own position and orientation during insertion, reducing the need for complex alignment procedures and specialized insertion equipment.
3Ease of operation
If screws are screwed into FDM components, then assembly is simple, but the anisotropic material structure causes layer separation and weak connections
Solution Approach 1:
The threaded sleeve acts as a mediator that interfaces with the FDM component through methods suitable for the material's anisotropic structure (heat embedding, adhesive bonding, or integrated design), distributing loads across multiple layers. The screw then engages with the isotropic sleeve material, avoiding direct stress concentration on the anisotropic FDM layers and preventing separation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method increases the strength and stability of screw connections in FDM components by preventing unscrewing and enhancing the overall firmness of the connection through heat-induced filament adherence to the threaded sleeve.
Implementation Method 1
assembling with heat input in a component manufactured by FDM process
Implementation Method 2
melting and adhering the filaments to the thread geometry
Implementation Method 3
melting and adhering the filaments to the thread geometry
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The invention relates to a threaded sleeve (19) for assembling with heat input in a component manufactured by FDM process (37). The threaded sleeve comprises a groove (15) along its longitudinal axis. Further, the outwardly facing surface of the threaded sleeve comprises a self-tapping thread which is divided into two sections (2, 4) along the threaded sleeve's longitudinal axis. The first section comprises a constant pitch diameter and the second area comprises a pitch diameter decreasing along its longitudinal axis. The inwardly facing surface of the threaded sleeve comprises a metric thread (21). Furthermore, the invention relates to a KIT, a system and a method for assembling with heat input the above-mentioned threaded sleeve in a component manufactured by FDM process.