Problem 2 (33 points) - CNC Milling Machine Gantry You're designing an X-Y gantry stage for a CNC machine (the part that moves the tool). You've chosen to use a timing belt and pulley system to create the motion. The pulley is fixed to the shaft with a key. The d = 0.25 in diameter, L = 6 in shaft is simply supported at points A and B and the forces on the dp = 2 in diameter pulley at point C are shown below. Ignore friction. 20 lb 6 in D 2 in 2 in 0.25 in 10 lb 3 in .B b) (15 points) Use Mohr's circle to find the principal planes and principal stresses at point D. Additionally, find the maximum shear stress and the plane of maximum shear stress. Find the corresponding normal stress at the point of maximum shear. c) (3 points) How do you interpret your analysis? What does it mean for the shaft design?