Drum Drive Gearmotor Selection

I’m designing a slow-turning drum and need an experienced engineer to specify both the AC motor and the reduction gearbox that will drive it. The drum must rotate steadily at 6 RPM and the load calls for less than 100 Nm of torque on the output shaft. Space is limited, so overall package size and mounting arrangement have to be considered alongside efficiency and durability. What I need from you is a clear, calculation-backed recommendation: the appropriate gear ratio, motor power, frame size, and any duty-cycle or thermal considerations that might affect service life. Please base the sizing on readily available industrial components—ideally IEC-frame or NEMA equivalents—so I can source them quickly. Deliverables • A brief sizing report showing assumptions, torque and speed calculations, and safety factors • Specific part numbers (or equivalent alternatives) for the gearbox and the AC motor, with links to datasheets • Any installation notes (lubrication, alignment, coupling type) that are critical for reliable operation Accuracy and clarity are more important than length. If you use a tool such as SolidWorks, MATLAB, or similar for the calculations, include the native file or a PDF printout so I can follow your logic.