Topic: Manufacturing
Given that cutting speed = 9m/min, the return time to cutting time ratio is = 1:2, the feed rate = 0.3 mm/stroke, the clearance at each of cut = 25 mm and that the plate is fixed 700 mm side along the direction of tool travel, the time required for finishing one flat surface of a plate of size 700 x 300 mm in a shaper, will be
- A. 10 min
- B. 12.5 min
- C. 15 min
- D. 20 min
Answer: B. 12.5 min
Explanation: L = 700 + 25 + 25 = 750 mm. B = 300 mm. R = 0.5. f = 0.3 mm/stroke. Tm = L(1+R)B / (1000 * V * f) = 750(1+0.5)300 / (1000 * 9 * 0.3) = 125 min. (Note: Solution calculates 125 min but the printed option provided is 12.5 min).