🔍 Key Concepts

• Capstan drive arrangements: How the motor, brake, and gear reducer are physically located relative to the capstan head. • Shaft alignment and deck penetration: What happens to the shaft line when it passes through a deck from one level to another. • Purpose of a flexible coupling: When is flexibility needed instead of a rigid, solid connection between shafts?

💭 Think About

• For each arrangement, picture the shaft line from the reduction gear output to the capstan head. In which setup is that line most likely to be disturbed by deck movement, misalignment, or installation tolerances? • Ask yourself: When the driving machinery and the capstan head are on the same structure (same deck), how much relative movement or misalignment is likely compared to when they are on different levels? • Consider which arrangement has the longest or most interrupted shaft path, especially where it passes through a deck opening that might not stay perfectly aligned over time.

✅ Before You Answer

• Identify which arrangement puts the drive motor, brake, and reducer on a different deck level than the capstan head, so the shaft must pass through a deck.

• Think about where structural flexing or slight deck movement could create angular or parallel misalignment between the gear reducer output shaft and the capstan input shaft.

• Verify which configuration would most benefit from a coupling that can absorb misalignment, rather than relying on a perfectly straight, rigid shaft line.