3 Sheet and Answer Material Removal Prof.alaa El-Hakim Ahmedawad

Metal Removal
Theory of Metal Cutting 3rd Year Production
Exercise 3 Conventionai (Jutting
- Calculate the cutting force components and the power consumption in machining a St50 workpiece with a cemented carbide turning tool given the following data :
- Workpiece dia. = 80 mm.
s = 03 mm/rev
Depth of cut = 5 mm Cutting speed = I'OO m/min Tool geometry :
-6°
Y X. a r
___Aj--;------- 45* 4 0 L 6° L 0
Overall efficiency =#0%
JG30 workpiece 300x120x40 mm3 is to be machined in a single pass on a
, . • 1 a p ,,,4- «-f nower consumption in each of the following cases :,
i- HSS plain milling cutter D = 150 mm, B = 140 mm, z = 12 teeth (strargni).
ii- Milling cutter same as in (i) but with a helix angle 30°.
iii- Face milling cutter 6150 mm, z - 12 teeth x = 45°.
Given that in ail cases : sz= 0.2 mm/tooth v " 30 m/min,
3- A 4,20 rmn HSS twist drill is used to drill holes in a solid St50 workpiece using teed of 0.2 mm/rev and a spindle speed of 600 rpm.
- Determine the drilling torque and the thrust force.
- Calculate the power consumption at the motor terminals.
(llm = 50%, Tl- = 80%) . .,.
What will be the torque, thrust force and power consumption it the previous hole cp20 mm is enlarged using a twist drill cp30 mm under the same cutting conditions as abovementioned
.... » t ...
4- A HSS peripheral milling cutter, cp50mm x 50mm, helix angle = 30°, z = 12 teeth, is used for upmilling the surface of a steel block 40mm width, 200mm length and 30mm thickness, down to 25mm using a cutting speed of 30 m/min and a feed rate of 300 mm/min.
Determine the torque on the main spindle and the total motor power, given that Ks, ,=2000N/mm2, Fc2: Faz: Frz - 2 : 1 : 1 , n = 50%
5- It is required to drill holes in StoO workpiece giving the following specifications : Motor power: . '5 kW
Overall mechanical efficiency : 60 %
Max. permissible axial thrust: I f000 N
Max. permissible spindle torque : 100 Nm
Determine the maximum hole diameter that can be drilled in that material, the corresponding feed and spindle speed.
What will be the time required to drill such a hole to a depth of 50 mm.
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