Fall 2025 EML6324 Fundamentals of Production Engineering HW-5 (Due November 12, 2025)
Q1. A roughing operation generally involves which one of the following combinations of cutting conditions:
(a) high R, f, and d;
(b) high R, low f and d;
(c) low R, high f and d; or
(d) low R, f, and d,
where R = nose radius, f = feed, and d = depth of cut? Explain why.
Q2. A 150 mm long normalized 1045 steel shaft is turned down from a diameter of 100 mm to 90 mm in a single pass. The side cutting edge angle σ is 0°, the cutting speed v is 135 m/min, and the feed per revolution fr is 0.22 mm. Determine (a) the chip area A [mm2
], (b) the material removal rate Q [cm3
/min], (c) the tangential component of the cutting force Ft [kN], (d) the power needed to drive the turning operation P [kW], and (e) the machining time t [min].
Q3. A lathe is used to machine a taper of 1 mm per 10 mm on bar stock 120 mm in diameter. (The chucked end is larger than the other end.) A cut is made with an initial depth of cut of 4 mm at a feed rate of 0.2 mm/rev and a spindle speed of 150 rpm. Calculate the average material removal rate [mm3
/min].
Q4. As the depth of the hole increases in drilling, rotational speeds and feeds should be reduced. Explain why.
Q5. A 14 mm diameter hole needs to be drilled in a normalized 1035 steel workpiece using a twist drill with a feed per revolution of 0.3 mm and a maximum cutting speed of 30 m/min. Calculate (1) the maximum spindle speed [rpm], (2) the drill feed rate [m/min], (3) the material removal rate, [cm3
/min] (4) the tangential cutting force [N], and (5) the torque [N·m] and power [kW] required for the operation.
Q6. Reaming is used for which of the following functions? (three correct answers)
(a) to accurately locate a hole position
(b) to enlarge a drilled hole
(c) to improve surface finish on a hole
(d) to improve tolerance on hole diameter
(e) to make an internal thread
Q7. Describe the difference between up milling and down milling?
Q8. Down milling has been found to have a lower tendency to chatter than up milling. Explain why.
Q9. A milling operation is being performed similar to the one shown in Fig. 7.30 in the textbook. The feed per tooth c is 0.2 mm, side cutting edge angle σ is 30°, and start and end angles ϕs and ϕe are 30° and 160°, respectively.
(a) Determine the mean chip thickness hm [mm].
(b) Draw a graph of h vs. ϕ, and indicate the variation of h on one tooth over two revolutions of the cutter.
Q10. A four-fluted end mill 40 mm in diameter is used to perform. an up-milling operation as shown in Fig. 7.29a in the textbook (ϕs is 0°); the workpiece is normalized 1035 steel. The axial depth of cut aa is 20 mm, the radial depth of cut ar is 25 mm, and the side cutting edge angle σ is 0°. The cutting velocity v is 45 m/min, and the feed per tooth c is 0.25 mm. Calculate (a) spindle speed n [rpm], (b) feed rate f [mm/min], (c) mean material removal rate Qm [cm3
/min], (d) mean chip thickness hm [mm], and (e) mean power P [kW].