How to Design and 3D Print Gears for Optimal Performance: A Step-by-Step Guide Using Onshape

In the world of 3D printing, gears are fundamental components that play a crucial role in mechanical systems. This tutorial will guide intermediate users through the process of designing and 3D printing various types of gears—spur, helical, and herringbone—using Onshape CAD software. Additionally, we will compare these gear types and discuss material selection for enhancing performance.

1. Understanding Gears and Their Types

Overview of Gear Types:

• Spur Gears: The most common type, ideal for applications requiring simple, straightforward design. They have straight teeth and are used where the gears operate parallel to each other.
• Helical Gears: These gears feature angled teeth, providing smoother and quieter operation, along with the ability to handle higher loads.
• Herringbone Gears: Combining the advantages of helical gears, herringbone gears consist of two sets of helical gears, eliminating axial thrust common in helical designs.

2. 3D Printing Techniques for Gears

To effectively 3D print gears, it’s essential to understand both the printing techniques and the design considerations. For this guide, we’ll focus on Fused Deposition Modeling (FDM) printing, which is the most common method for DIY applications.

3. Selecting the Right Materials

FDM 3D Printing Materials:

• PLA (Polylactic Acid): Easy to print and ideal for prototypes, but it is relatively brittle.
• ABS (Acrylonitrile Butadiene Styrene): More durable than PLA with better impact resistance, suitable for functional parts.
• PETG (Polyethylene Terephthalate Glycol-Modified): A versatile option that combines ease of printing with durability.

Print Settings for Optimal Performance:

• Minimum of 3 perimeters on all sides.
• 15% infill for a balance of strength and weight.
• Layer thickness should not exceed 0.3mm.

4. Designing Gears Using Onshape

Designing with FeatureScript:

Onshape’s FeatureScript allows for the customization and creation of gear designs with precision. Here’s how to get started:

1. Use Pre-made Gear Designers: Source gear design scripts from Onshape forums to save time.
2. Modify Variables: Adjust parameters such as the number of teeth and diameters to fit your needs.

Design Tips:

• Gears in Pairs: Design gears in pairs to guarantee proper meshing.
• Accurate Geometry: Ensure accurate involute tooth geometry when creating spur gears.

5. Best Practices for 3D Printing Gears

Design Considerations:

• Clearance and Fit: Maintain proper clearance to address potential warping or layer thickness discrepancies.
• Post-Processing: Depending on material choice and print quality, consider lubricating gears to improve performance.

Gear-Specific Tips:

• For Spur Gears: Prioritize precision in tooth shape for effective meshing.
• For Helical Gears: Pay attention to the helix angle and pitch during design for optimal interaction.
• For Herringbone Gears: Use two opposing helical gear designs for performance benefits.

6. Gear Testing: Analyzing Performance and Strength

After printing, it’s crucial to conduct strength tests to evaluate performance. This involves testing for:

• Wear resistance
• Load capacity
• Operational smoothness

Conclusion and Further Resources

Designing and 3D printing gears using Onshape can yield customized solutions for various engineering applications. By understanding gear types, material properties, and best design practices, you can optimize for performance and reliability. For more comprehensive resources, consider exploring the following:

• Onshape forums for community-shared scripts.
• McMaster Carr and GrabCAD for existing gear models and designs.

Ready to start printing? Dive into your design today, experiment with different materials, and optimize your gears for real-world applications!