College of Technological Studies Dept. of Mech. Prod. Tech. Production Technology (MEP232)

Final Exam – 2/2001/2002, Dec. 2001 –Group (2) Time: [180 mins] - Marks: [60]

Student Name: Student Number:

Information for Student:

1) Answer All Three questions

2) Answer should be within the provided space on one side only.

2) Use descriptions and free-hand sketches as much as you can.

3) Assume any possible missing information.

4) No materials are allowed.

Question Number	Final [50]	Homeworks	Remarks
Question One [Twenty Marks]
Question Two [Fifteen Marks]
Question Three [Fifteen Marks] Question Four [Ten Marks]
Total

Please note this is a cover page Exam starts ext page

Question One: Milling Operations {Twenty Marks}

Cutter

Workpiece

Operation & Cutting Conditions

· Coated Carbide Inserts.

· Cutter Diameter (Dc)=20 cm.

· Cutter width (bc) = 30 mm

· Helical Teeth Number (Z) = 20.

· Hard Alloy Steel block with dimension [600*300*200] mm.

· Removed thickness (h)= 41 mm.

· Specific Energy (Ks):50 kp/mm2

· Material resistance (RI) : 0.25

· Slab milling

· Cutting Speed (Vc): 2000 mm/sec.

· Feed (fr) =6 mm/rev.

Part (B) Machining Time (Four and Half Marks)

a) Rough Machining Time (Tr) = ------------------------------------------------------------------------------------------------------

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b) Finish Machining Time (Tf) =---------------------------------------------------------------------------------------------------------

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c) Total Machining Time (T) = ------------------------------------------------------------------------------------------------------------

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Results	Rough Time	Finish Time	Total Time
Results

Part (C) Metal Removal Rate, Feed Power, Cutting Forces and Spindle Power and Torque [Seven Marks]

· Metal Removal Rate (MRR) =---------------------------------------------------------------------------------------------------

· Feed (Table) Power =--------------------------------------------------------------------------------------------------------------

· Main Cutting Force (Fc) =-------------------------------------------------------------------------------------------------------

· Radial Force Component (Fr) =------------------------------------------------------------------------------------------------

· Axial Force Componet (Fa) = --------------------------------------------------------------------------------------------------

· Spindle Power (P) =--------------------------------------------------------------------------------------------------------------

· Torque on Cutter Arbor (Mtg) =---------------------------------------------------------------------------------------------

Results	MRR	Feed Power	Fc	Fr	Fa	P	Mtg
Results

Part (D) Load Curve [Five Marks]

Discuss the above case from surface finish and dimensional accuracy point of views and, propose a better machining conditions

Question Two: Surface Grinding Operations [Fifteen Marks]

Cutter

Workpiece

Operation & Cutting Conditions

· Grinding Wheel

· Diameter (Dg)=200mm.

· Width (bg) = 45 mm.

· Hard Alloy Steel Block. [500*200*150 mm].

· Removed thickness (h) =2.5 mm.

· Specific Cutting Energy (Ks) = 4500kp/cm2.

· Work Strokes (Nw)= 2.5 ds/sec.

· Wheel Speed=2000 m/min.

· Rough & Finish depthes= 0.3 and 0.1 mm respectively.

· Tcav= 0.02 mm.

a) Wheel Speed (Vg) = ----------------------------------------------------------------------------------------------------------------

b) Vgf = -----------------------------------------------------------------------------------------------------------------------------------

c) Workpiece Speed (Vw) = ------------------------------------------------------------------------------------------------------------

d) & Vwf = ------------------------------------------------------------------------------------------------------------------------------

e) Relative Speed (Vr) = -----------------------------------------------------------------------------------------------------------------

f) Rough feed (Sr) = ---------------------------------------------------------------------------------------------------------------------

g) Finish feed (Sf) = ----------------------------------------------------------------------------------------------------------------------

h) (itr) = -----------------------------------------------------------------------------------------------------------------------------------

i) (itf) = ---------------------------------------------------------------------------------------------------------------------------------

j) (iBr) = ----------------------------------------------------------------------------------------------------------------------------------

k) (iBf) = ----------------------------------------------------------------------------------------------------------------------------------

Results	Vgf	Vwf	Vr	Sr	Sf	Itr	itf	IBr	iBf
Results

Part (C) Machining Time (Three Marks)

a) Rough Machiming Time (Tr) = --------------------------------------------------------------------------------------------------

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b) Finish Machining Time (Tf) = --------------------------------------------------------------------------------------------------

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c)Total Machining time (T) = --------------------------------------------------------------------------------------------------

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Results	Rough Time	Finish Time	Total Time
Results

Part (D) Cutting Forces and Power (Three Marks)

a) Main Cutting Force (Pz) =------------------------------------------------------------------------------------------------------------

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b) Wheel Motor Power (Pg) = ----------------------------------------------------------------------------------------------------------

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c)Work Motor Power (Pw) =------------------------------------------------------------------------------------------------------------

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Results	Pz	Pg	Pw
Results

Part (E) Draw Sketches indicating( Three Marks)

a) Horizontal Rotational SurfaceGrinding Operations B) External Floating Grinding Operation

Question Three: Broaching Operations {Fifteen Marks}

Cutter

Workpiece

Operation & Cutting Conditions

· Internal round Pull Broach.

· Hard Alloy Steel Block with 90 mm length.

· Initial radius (ri) = 25 mm.

· Inal radius (ro)= 50 mm.

· Specific Energy (Ks):3000 kp/cm2

· Max Pulling Speed : 3 m/sec.

· Rough Depth per tooth =0.2 mm.

· S-Finish Depth /tooth (tsf)=0.15mm.

· Finish Depth/tooth (tf)=0.1 mm.

Part (B) Pitch Calculations (One and Half Marks)

· Rough Pitch (Pr) = --------------------------------------------------------------------------------------------------------------------

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· Semi-Finish Pitch (Psf)= ----------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------

· Finish Pitch (Pf) =------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------

· Involved teeth (Zir)= -----------------------------------------------------------------------------------------------------------

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· Involved Thickness (hir) = ----------------------------------------------------------------------------------------------------

Results	Pr	Psf	Pf	hir
Results

Part (C) Broach Parts Lengths Calculations (Two and Half Marks)

· Rough Length (Lr) =-------------------------------------------------------------------------------------------------------------

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· Semi-Finish length (Lsf) =------------------------------------------------------------------------------------------------------

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· Finish-Length (Lf) =-------------------------------------------------------------------------------------------------------------

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· Effective Length (Le) =----------------------------------------------------------------------------------------------------------

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· Total Length (Lb) =---------------------------------------------------------------------------------------------------------------

Results	Lr	Lsf	Lf	Le	Lb
Results

Part (D) Force and Power calculations (Three Marks)

· Cutting Force (Pz) = ------------------------------------------------------------------------------------------------------------

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· Consumed Power (P) = ---------------------------------------------------------------------------------------------------------

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· Minimum Motor Power (Pm) = ----------------------------------------------------------------------------------------------

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Results	Pz	P	Pm
Results

Part (E) Draw a sketch indicating the mechanical driven broaching machine (Three marks)

Question Three: CNC Dyna Program {Ten Marks}

Q: 1 Write a computer program in Conversational format for DYNA Milling machine.

Program the continuous path; use End mill tool diameter 10 millimeters. Feed Rate 50 millimeters / Minute in XY plane and 40 millimeters / Minute along Z-axis. Your tool path should be on the part boundary. Using Point to Point positioning program the hole locations, drill two holes (use same tool for drill programming). Depth of cut should not increase 4 millimeters for continuous path; depth of cut for drill holes should be 10 millimeters.

First movement is a rapid movement at the distance of X 10 mm , Y 10 mm from program reference zero.

Block Seq.	DYNA COMMANDS	Block Seq.	DYNA COMMANDS	Block Seq.	DYNA COMMANDS

Final Exam – 2/2001/2002, Dec. 2001 –Group (2) Time: [180 mins] - Marks: [60]

Question Number

Homeworks

Remarks

Part (C) Metal Removal Rate, Feed Power, Cutting Forces and Spindle Power and Torque [Seven Marks]

a) Main Cutting Force (Pz) =------------------------------------------------------------------------------------------------------------

Part (D) Force and Power calculations (Three Marks)