Define preventative maintenance - NSC Mechanical Technology Fitting and Machining - Question 8 - 2017 - Paper 1

Ensuring that a machine is switched off and locked out is vital because it prevents accidental activation of the machine while maintenance is being performed. This lockout procedure safeguards technicians from potential injuries that could occur due to unexpected machine movements.

Clutch-pedal free play refers to the distance the pedal moves before the slack is taken from the linkage and the release bearing. This distance is crucial for proper engagement and disengagement of the clutch.

The viscosity index is a measure of how much the oil's viscosity changes as temperature varies. A higher viscosity index indicates that the oil maintains its viscosity better across a range of temperatures.

1. Worn friction linings, which reduce the effectiveness of the clutch.
2. Weak or broken springs that hinder the clutch's ability to engage and disengage properly.

Grease has a very high viscosity to ensure that it coats and adheres to the bearing surfaces it lubricates. This characteristic minimizes wear and enhances the longevity of mechanical components.

Cutting fluid is a mixture of soluble oil and water that is used to cool and lubricate the tool and the workpiece during machining processes.

The viscosity of a cutting fluid should be low to allow for easy flow and effective dissipation of excess heat generated during cutting operations, thereby enhancing tool life and workpiece quality.