servo_sizer/memory/2025-04-28.md

Timing Belt Calculator - External Load Improvements

Issue Identified

Current timing belt calculation program only considers gravity and friction forces, which is insufficient for real-world applications where external loads (cutting forces, fluid resistance, spring forces, etc.) are present.

Proposed Solutions

Short-term Improvement (Quick Implementation)

1. Add "externalForce" parameter (N) to existing calculation
2. Modify load torque calculation: totalForce = gravityForce + frictionForce + externalForce
3. Support positive (resistance) and negative (assistance) values
4. Add "externalTorque" parameter for direct torque loads

Long-term Improvement (Comprehensive Solution)

1. Application Type Selection:

   • Vertical lifting
   • Horizontal pushing/pulling
     
   • Rotational loads
   • Custom scenarios

2. Load Component Breakdown:

   resistanceComponents: {
      friction: 10,      // N
      cuttingForce: 50,  // N  
      springForce: 30,   // N
      fluidDrag: 15,     // N
      other: 0           // N
   }
   

3. Enhanced Calculation Formula:

   Total Load Torque = [Gravity Component + Friction + ΣExternal Forces + Direct External Torque] × Pulley Radius ÷ Efficiency
      
   Where:
   - Gravity Component = mass × gravity × cos(installationAngle)
   - Friction = mass × gravity × frictionCoeff × sin(installationAngle)
   - External Forces = user-defined various resistance forces
   - Direct External Torque = torque directly acting on shaft
   

4. Additional Features:

   • Dynamic load curves (varying loads at different positions/speeds)
   • Application-specific safety factor recommendations
   • Power requirement calculations

Implementation Priority

• Short-term solution should be implemented first for immediate practical use
• Long-term solution provides comprehensive engineering analysis capabilities

Files to Update

• timing_belt_calculator.js (or equivalent calculation module)
• UI component files for parameter input
• Documentation files explaining new parameters

Git Commit Strategy

• Create feature branch: feature/external-load-support
• Implement short-term improvements first
• Test with various external load scenarios
• Merge when validated
• Plan long-term improvements as separate development phase