3D Printed Gear Guide: Which One is Better?

Gears are key components in motion transmission systems, and 3D printing allows you to create custom gears tailored to your project needs, enhancing mechanical design. Different types of gears (such as spur gears, helical gears, and herringbone gears) can impact noise levels, transmission efficiency, and service life. This guide will compare the advantages and disadvantages of three different 3d printed gear designs in detail.

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Spur Gears

Spur gears have teeth that are parallel to the gear axis and are the simplest and most common type of gear.

Advantages:

Easy to 3D print: The geometry is simple, and design and manufacturing are quick.

Low cost: Requires less material consumption and minimal post-processing.

Disadvantages:

High noise: The teeth mesh suddenly during meshing, causing vibrations and noise, especially at high speeds.

Limited load capacity: High-speed operation accelerates wear and shortens service life.

Spur gears have teeth that mesh parallel to the gear axis, meaning meshing occurs suddenly across the entire gear surface, causing significant vibration and noise. Despite this, spur gears are the easiest to manufacture and the most cost-effective, making them the preferred choice for low-load and simple applications.

Helical Gears

Helical gears have teeth that are angled to the gear axis, which allows for smoother meshing, reducing noise and improving efficiency.

Advantages:

Low noise and vibration: Suitable for high-speed applications requiring smooth operation.

More durable: Multiple teeth engage simultaneously, distributing the load more evenly and enhancing lifespan.

Disadvantages:

Axial thrust: Generates side loads, requiring additional bearing support.

Higher 3D printing difficulty: The helical structure demands precise layer alignment to ensure print quality.

The teeth of helical gears are inclined at a specific angle to the gear axis, known as the helix angle. Due to this angle, meshing does not happen suddenly along the entire width of the tooth but gradually, resulting in less impact compared to spur gears. As a result, helical gears operate more quietly, with less vibration, and more smoothly, particularly at high speeds. However, they generate additional axial forces, which increase with the helix angle and may require extra bearing support to counteract the forces, generating more heat and leading to power losses. Therefore, it's recommended to keep the helix angle under 25 degrees. Additionally, due to the structural complexity, 3D printing helical gears is more challenging and requires higher precision for proper layer alignment and print quality.

Herringbone Gears

Herringbone gears consist of two opposing helical gears that counteract axial thrust while maintaining smooth transmission.

Advantages:

No axial thrust: Eliminates side forces, reducing bearing and shaft wear.

Extremely durable: Suitable for high-load and high-torque applications.

Smooth and quiet operation: Ideal for precision applications.

Disadvantages:

Complex design: Requires precise symmetry in the arrangement of the helical teeth.

Difficult to assemble: More challenging to disassemble and assemble compared to spur or helical gears.

As mentioned earlier, helical gears generate axial thrust, but herringbone gears solve this problem. Herringbone gears use two opposite helical gears (left-handed and right-handed spirals) to cancel out the axial forces. When herringbone gears mesh, the teeth lock together. These herringbone gears work smoothly and quietly, just like helical gears, without unnecessary movement, making them ideal for high-torque projects. To design herringbone gears, start by creating a helical gear in modeling software, then mirror it relative to the top or bottom surface to obtain the herringbone gear. The design and production of herringbone gears are more difficult than the other two types, and assembly is also more complex.

By understanding the pros and cons of different 3D-printed gears, you can optimize your design based on project requirements to enhance the durability and functionality of your gears. If you need high-quality 3D-printed gears, JLC3DP offers professional 3D printing services with a variety of materials to choose from, enabling precise printing of high-torque gears to meet your project needs.