4. It is required to design a feed drive system for a 3D printer using a DC motor to drive a ball screw through a gearbox with a reduction ratio of 8 to achieve a linear movement along the X-axis of the 3D printer as shown in Fig. Q 4. The lead of the ball screw is 2 mm. To achieve accurate control of the axis, a feedback control system is employed using a linear potentiometer to measure the linear displacement of the axis. The axis displacement range is 0-100mm and the corresponding output of the potentiometer is 0-5V. An Arduino Uno is used as a controller to regulate the movement of the axis based on the feedback from the sensor. The output of the sensor is connected to one of the analogue inputs on the Arduino (AIO). (a) What is the minimum linear displacement that can be measured using this setup (i.e., resolution)? (b) If the above resolution is not enough to achieve the target manufacturing accuracy of the 3D printer. Two different solutions may be used : 1) To use an incremental rotary encoder attached to the motor shaft (Note: the encoder will be attached to the motor not the ball screw) or 2) To replace the controller (i.e., the Arduino Uno) with a controller which includes an analogue to digital converter (ADC) with higher specifications. If the requested resolution of the system is 10m i) For the first option, what is the minimum number of pulses per revolution required for the rotary encoder to achieve the desired precision? ii) For the second option, what is the minimum number of ADC bits to achieve the desired precision? With this minimum number, what is the resulting resolution? Gearbox Motor Ball screw shaft, Ball screw nut Figure Q4 [3] [6] [6]