Flexible Coated Rotating Elements for Metallic Filament Extrusion

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Solution Overview

Problem

Current 3D printing machines are not configured to handle metallic filaments due to their fragility, low feed rates, and high risk of print failures, limiting their ability to utilize materials with a high metal content.

Innovation Solution

The development of 3D printing extruders with rotating elements covered in a flexible coating to grip and advance metallic filaments, allowing for efficient deposition in existing 3D printers, which can be retrofitted without specialized tools, using a combination of cylindrical gears and a knurled drive transmission to manage the fragile materials effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional drive-transfer gears are used to feed printing material, then feeding can be performed with existing 3D printers, but metallic filaments cannot be handled effectively due to fragility and insufficient grip

Engineering Contradiction:

Improveability to handle metallic filamentsVSAvoidprint failure risk

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the surface parameter of the drive-transfer gears by adding a flexible coating layer. This coating modifies the friction characteristics between the gears and metallic filament, enabling effective grip without damaging the fragile material. The coating transforms the hard, slippery gear surface into a compliant, high-friction interface suitable for metallic filaments.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The drive-transfer gears are constructed as composite structures with a rigid core and a flexible coating layer. The rigid core provides structural strength and gear functionality, while the flexible coating provides the necessary friction and compliance for handling metallic filaments. This composite structure resolves the contradiction between needing hard gears for durability and soft surfaces for gentle material handling.

Inventive Principle:

Principle #40Composite materials

2Productivity

If metal powder substrate is used with direct printing method, then finished target product can be produced, but the material is fragile and difficult to feed consistently

Engineering Contradiction:

Improvefeed rateVSAvoidmaterial handling difficulty

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The flexible coating on the drive-transfer gears changes the interaction parameters between the feeding mechanism and metallic filament. The coating increases friction and provides compliance, enabling consistent feeding at higher rates without damaging the fragile metallic material. This allows the system to achieve both high productivity and ease of operation.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If existing 3D printers are modified to handle metallic filaments, then high metal content filaments can be used, but specialized tools and manufacturer assistance are currently required

Engineering Contradiction:

Improvemetallic filament compatibilityVSAvoidretrofit complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The solution segments the modification process into separate, manageable components. The flexible coating is applied as a distinct layer that can be installed independently on existing drive-transfer gears. This segmentation allows operators to retrofit existing printers without requiring complete system replacement or specialized manufacturer tools, thereby improving ease of manufacture while maintaining adaptability to metallic filaments.

Inventive Principle:

Principle #1Segmentation

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

Enables the production of semi-finished target objects with metallic filaments containing up to 85% metal, ensuring consistent and high-quality printing by maintaining adequate friction and reducing material damage, thus overcoming the limitations of existing 3D printers with metallic substrates.

Implementation Method 1

the two rotating elements are covered with a flexible coating, which is configured to generate a suitable amount of friction with the metallic filament (to enable such rotating elements to grip and advance the metallic filament forward towards the print head)

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS11738509B2Extruders and printing machines for 3D metal printing

Publication Date: 2023.08.29 3DGENCE AMERICA INC

AI summary

Extruders for 3D printing machines are disclosed, which are configured to print with fragile metallic filament substrates. The extruders include two rotating elements, each of which is at least partially cylindrical, with the two rotating elements being positioned parallel to each other (with a first of the rotating elements being configured to rotate in a first direction and a second of the rotating elements being configured to rotate in a second opposite direction). The extruders are operably connected to a transmission, which is configured to drive rotation of the rotating elements in the first direction and the second opposite direction. The extruders further include a metallic filament contact zone located in a cylindrical area of each of the two rotating elements, along with a flexible coating that at least partially covers the metallic filament contact zone. The flexible coating is configured to be removed and replaced by an operator of the 3D printing machine.