Cycloidal Drive

Realizing I needed a serious gear reduction system for my 6-axis robotic arm, I started researching different options and eventually landed on cycloidal drives. After watching a few demonstrations, I was honestly impressed by how elegant and compact the mechanism was. I wanted to design a version that was slightly overkill for my application, so I targeted a 49:1 reduction ratio, which would provide more than enough torque for the arm joints.

I fully modeled the drive in SolidWorks, selecting metal dowel pins, sleeve bearings, and ball bearings I could easily source from Amazon, and built the geometry around real component dimensions. The first version looked great, but it was much larger and bulkier than I wanted. I redesigned it to be more compact, but the truth was obvious: this specific drive was better suited for a much larger motor than a NEMA 17.

Even though I couldn't manufacture the design at the time—my 3D printer had unfortunately died—I still plan to revisit it. I'd like to print a PLA version and possibly even machine an aluminum version later to compare stiffness, backlash, and overall performance. For now, it remains another project stuck behind my lack of reliable manufacturing tools.