Project brief
Decisions and iterations
Size Pinion 1
AGMA bending and contact stress calculations gave design factors SF 1.6 and SH 1.2 for the specified material assumptions.
Resolve Shaft 1 loading
Shear and bending moment diagrams in two planes identified shoulder and keyseat critical locations for Goodman fatigue analysis.
Select bearings
SKF 61817 bearings were specified against calculated life and reliability requirements; the calculation workbook preserves the assumptions.
Check the assembly physically
The printed prototype let the team check assembly fit and drivetrain motion.
Results and context
The calculations target 4 HP at 1500 RPM and a 55,000-hour design life. The plastic prototype checked assembly and movement; testing at the design load would require a separate working gearbox.
Shaft calculation review: Final report · page 10 ↗ flags a possible variable error in the shaft fatigue factors.
Technical details
AGMA calculations
The design is 35:1 overall, with 5:1 and 7:1 stages. Pinion 1 calculations used AGMA bending and contact factors; the complete workbooks and drawing are linked below.
Shaft fatigue and bearing selection
Shaft 1 used two-plane shear and bending moments, shoulder/keyseat checks, Goodman fatigue, and SKF 61817 bearing selection. The 55,000-hour life was a design target. The report flags a possible variable error in the shaft fatigue safety-factor calculations (page 10); those calculations require review.
Drawings and prototype
The printed model made assembly clearances and drivetrain movement inspectable before any load-capable build.
Project values and components
| Total ratio | 35:1 (5:1 × 7:1) |
|---|---|
| Input / Output | 1500 RPM → 42.86 RPM |