Light-Duty Robotics Planetary Gearbox -- 2

I need a complete planetary gearbox design tailored for a light-duty robotics application. The unit must deliver a reduction somewhere in the 10:1–50:1 range while keeping size and weight to a minimum so the robot arm it sits inside can stay nimble and energy-efficient.

Here is what I expect:
• A 3-stage (or otherwise appropriate) concept that achieves the specified ratio with smooth, backlash-conscious motion.
• 3D CAD files and dimensioned drawings ready for prototyping; STEP is essential and the native file from your preferred package (SolidWorks, Inventor, Fusion 360, etc.) is welcome too.
• Basic strength calculations showing that gears, carrier pins, and shafts comfortably handle light-duty loads typical of small collaborative robots.
• A short design note highlighting chosen materials, lubrication approach, and any tolerances critical to assembly.

I’m happy to clarify space constraints and input speed once we begin, but the core deliverable is a design I can send straight to the machine shop for a first article. If you have prior examples of compact planetary sets, feel free to share screenshots or snippets of your work so I can see your style and engineering depth.