JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III MACHINE TOOLS Previous Question Paper (September - 2021 - R13)
Answer any five questions
All questions carry equal marks
Main
With a neat sketch, explain principal angles of a single point cutting tool.
Answer
A single point cutting tool is defined by several principal angles that dictate its performance, tool life, and surface finish. These angles are typically defined in the American Standards Association (ASA) system.
Back Rake Angle: The angle between the face of the tool and a line parallel to the base of the shank, measured in a plane perpendicular to the base and through the cutting edge. It controls chip flow and tool strength.
Side Rake Angle: The angle between the face of the tool and a line parallel to the base, measured in a plane perpendicular to the side cutting edge. It helps in directing the chip away from the workpiece.
End Relief Angle: The angle between the portion of the flank immediately below the end cutting edge and a line perpendicular to the base. It prevents rubbing of the tool flank against the finished surface.
Side Relief Angle: The angle between the portion of the flank immediately below the side cutting edge and a line perpendicular to the base. It prevents rubbing against the workpiece surface.
End Cutting Edge Angle: The angle between the end cutting edge and a line perpendicular to the tool shank. It prevents the trailing part of the tool from rubbing against the finished surface.
Side Cutting Edge Angle: The angle between the side cutting edge and the side of the tool shank. It influences the chip thickness and the direction of chip flow.
Nose Radius: The curvature at the tip of the tool. It improves surface finish and increases tool strength.
A sketch would show the tool shank with these angles measured relative to the reference planes (base, longitudinal, and transverse planes).
A tool life of 80 minute is obtained at a speed of 30 metres per minute and 8 minute at 60 metres per minute. Determine the following: (i) Tool life equation (ii) Cutting speed for 4 minute tool life.
Answer
The tool life equation is given by Taylor's equation: V Tn = C.
Given data: V1 = 30 m/min, T1 = 80 min; V2 = 60 m/min, T2 = 8 min.
(i) Determining the tool life equation:
Now, calculate C using V1 and T1:
The tool life equation is: V T0.301 = 111.9.
(ii) Cutting speed for 4 minute tool life:
The required cutting speed is approximately 73.81 m/min.
Draw Merchant’s circle diagram to show cutting forces acting on cutting tool.
Answer
Sign in to view the complete answer paper.
Explain different types of chips formation with neat sketches.
Answer
Sign in to view the complete answer paper.
Distinguish among centre lathe, capstan lathe and turret lathe.
Answer
Sign in to view the complete answer paper.
List out various tool holding devices used in turret lathes. Describe briefly any two of them.
Answer
Sign in to view the complete answer paper.
Explain the crank and slotted link mechanism for the shaper ram with a sketch.
Answer
Sign in to view the complete answer paper.
Describe the kinematic scheme of planning machine.
Answer
Sign in to view the complete answer paper.
Sketch and explain the radial drilling machine in detail.
Answer
Sign in to view the complete answer paper.
Sketch and explain the working of fine boring machine.
Answer
Sign in to view the complete answer paper.
Explain the process of up-milling and down milling. What are the advantages of each process?
Answer
Sign in to view the complete answer paper.
Discuss briefly the vertical milling machine.
Answer
Sign in to view the complete answer paper.
Explain briefly the lapping process. Give the examples of lapping work.
Answer
Sign in to view the complete answer paper.
List and explain different machining parameters and related quantities on a broaching machine.
Answer
Sign in to view the complete answer paper.
Sketch and explain the working of cylindrical grinder.
Answer
Sign in to view the complete answer paper.
How abrasive is selected for grinding operation and state different types of abrasives used for grinding wheel? Explain.
Answer
Sign in to view the complete answer paper.