Question

Q5 In a machining experiment conducted by a machining centre in Subang. A probe was used, and the digitalized surface readings are presented in Figure Q5. The measurements are provided in Table Q5. (a) Calculate the Ra and Rq values. (6) Explain how the values obtained in (Q5a) can be reduced. Digitized data Table Q5 Point Value Point Value -33.2 S 4.5 -19.8 t 21.9 1 -4.2 u 6.1 13.7 10.1 12 35.1 24.9 46.1 49.6 р 24.8 y -11.1 9 1.3 -3.1 -7.7 Point Value 22.0 b 15.0 с 24.9 d 33,8 e 11.1 f -19.9 9 -30.2 h -23.9 i -23.2 fghijk 11 abcde Center (datum) line Surface profile Figure Q5 A (c) Friction is a force between two surfaces moving relative to each other. Friction always works in the direction opposite to the direction in which the object is moving. The amount of friction depends on the materials from which the two surfaces are made. In manufacturing processes, friction creates a lot of undesirable effects. Explain at least FIVE (5) manufacturing process applications where friction is a necessity.

Answer 1

To calculate the Ra and Rq values from the given digitized data, you need to follow these steps:

1. Calculate the mean (average) value of the data points.
2. Calculate the deviation of each data point from the mean.
3. Take the absolute value of each deviation.
4. Calculate the Ra value as the arithmetic average of the absolute deviations.
5. Calculate the Rq value as the square root of the mean of the squared deviations.

For explanation on how the values can be reduced, there might be missing information or context. However, some common ways to reduce Ra and Rq values include improving machining techniques, using better cutting tools, reducing vibration during machining, and using appropriate machining parameters.

Regarding friction in manufacturing processes, here are FIVE applications where friction is a necessity:

1. Metal Forming: Friction is essential in processes like forging, rolling, and extrusion to enable shaping and deformation of metal workpieces.

2. Grinding and Polishing: Friction between abrasive particles and the workpiece surface helps remove material and achieve the desired finish.

3. Sheet Metal Bending: Friction between the bending tool and the sheet metal assists in forming accurate and smooth bends.

4. Screw Fastening: Friction is necessary to create a secure joint when screws are tightened into materials like wood or metal.

5. Cutting and Machining: Friction plays a crucial role in processes like milling, turning, and drilling, enabling material removal and shaping of the workpiece.

Each of these applications requires controlled friction to achieve precise results and ensure the effectiveness of the manufacturing process.

Hope this helps, Rosie.
willkiddhill