[DIY] Split-Ring Dual Joined-Cycloids gear train - 3D Print

Unlike the Single Joined-Cycloids gear, a Dual Joined-Cycloids gear presents balanced centrifugal forces, and symmetrical forces on the stator and output rings, making it potentially more suited for higher load torques and higher speed.

So I made this simple model to get familiar with its principle. It has a 105:1 reduction ratio, 3mm eccentricity and is 120mm wide.

The Fusion360 CAD model (very messy), STEP and 3MF files are on Github

Feel free to copy, remix, whatever (non-commercially) 

Happy printing to all !

 

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Sections:

• Printing
• Assembly
• CAD
• Diagram (coming)
• Test Results (coming)
• Resources 

Printing

 

Settings

• 0.4mm nozzle, 0.24 layer height
• 2 walls, 3 top, 2 bottom
• 20% Support Cubic infill
• Normal Auto support, 10° Threshold Angle
• 0.5mm Support/object XY distance (easier to break supports free)

 

Assembly

 

Glue the shaft end on:

 Install the cycloidal pin-disc, dimple up, and the partial shaft:

Install the joined-cycloids, dimples up:

 

Glue the front pin-disc onto the pins, and glue on the front part of the shaft, ensuring that the dimples are all aligned: 

Glue the output hub to the wheel:

Install the output wheel and the front of the casing:

CAD

The cycloidal profiles were generated via a Fusion360 script from woodenCaliper on Github and with the help of this video from Howey 

 

Diagram

[coming] 

Test Results

[coming] 

Resources

I have not been able to find any research paper or documentation on this type of gear train. If anybody knows of any please drop a comment.

 

This said, Paul Gould published a video on this drive, which he calls Dual Linked Two stage Cycloidal Gearbox

 

Once again, shoutout to the extremely useful ME Virtuoso website where one can parametrically simulate their own planetary / wolfrom / cycloidal / harmonic / wave drives, and then download the STEP / DXF files. Some of which he also CNC'd or 3D printed, and tested on the ProMakina Youtube channel

 

Finally, I'm planning to design a robust version with bearings and put it through the same 16Nm torture test that the others went through. Will update the results section when done. But, for now, that's all folks !