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MECH1400 48 hour take home quiz 2021
1. This is an open book exam; you can use online resources.
2. You have 48 hours to complete and submit the quiz, it is expected it will take the
average student around 90-120 minutes to complete
3. Late submissions will NOT be accepted!
4. You must not collude with other students, do not discuss answers with them, share
information etc.
5. All written answers need to be typed (handwritten answers are only accepted for
calculations) and submitted in PDF format as one single document.
6. Clearly label which question you are answering in your document and present them
in the SAME order they appear in the question sheet. If it is not clear which
question your answer relates to, it will not be marked.
7. Any answers requiring calculations must show all working, be completed by hand,
photographed, and embedded within the same PDF document.
8. Physical copies of all hand calculations and drawings must be kept for 6 weeks and
provided to the UoS coordinator if requested.
9. Explain any assumptions you make, state any material properties used etc.
10. Provide answers in YOUR OWN WORDS, copying text from slides, tutorials or any
other resource will be considered academic dishonesty.
11. Do not add your name to your submitted document, they are marked anonymously,
Canvas will track submissions.


Section 1 (50 marks)


Part 1

1.1. List and explain three reasons why Engineers need technical drawings [3x2=6 marks]

1.2. List five main features that technical engineering detail drawings must contain and
explain why the feature is important [5 marks]
1.3. Explain the main differences between detail and assembly drawings [4 marks]

1.4. With relation to mechanical design, use two examples to describe and explain what is
meant by “constrained optimisation” [4 marks]
1.5. List five material properties of interest in mechanical design and explain why the
property is important when designing machinery [5 marks]
1.6. Using an example, explain the concept of surface finishes and why they are important
in mechanical design [3 marks]

1.7 Using an example, explain the concept of tolerances and why they are important in
mechanical design [3 marks]
1.8. Explain the difference between cutting feeds and cutting speeds and what impact they
can have on machining [4 marks]
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1.9. Describe what is meant by “additive manufacturing” and give an example of where it
might be used [4 marks]
1.10. Explain why water cutting may be preferred over laser machining for a part? [2 marks]

1.11. For the two-part assembly shown below, list and describe the processes required to
manufacture the assembled part (list steps in order using equipment available in the AMME
student workshop. The two threaded holes are M12 and M3. State any reasonable assumptions
you make. [10 marks]

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Section 2 Engineering Analysis (50 marks)



2.1a Which of the machines shown in the figures above, represents a reciprocating 2-stroke
petrol cycle engine (1 Mark).
2.1 b Provide one reason why you think your choice is correct and name one disadvantage of
the reciprocating 2-stroke petrol engine (2 Marks).




2.2 a On the stress and strain diagram shown above, discuss the region of the diagram that is
of most interest to a design engineer designing a compressed air powered engine, and include
your reasoning why. (2 Marks)

2.2 b Discuss a region of the stress and strain diagram that is important when considering
fasteners placed under very high tensile loads. (1 Mark)
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2.3 The solid (not hollow) 3mm diameter aluminium rivet shown in the image above has
undergone a shear failure;

2.3.a. Calculate the value of the force F in newtons that has caused the rivet to shear? (2.0
Marks)

2.3.b If the aluminium rivet was replaced with a mild steel rivet, what is the revised value of
the Force F (1.0 Mark)

2.4 a Calculate the mass (in grams) of a solid brass cylindrical piston; 19mm in diameter and
19mm in length. (1.0 Marks)

2.4b When selecting a material for a lightweight component that also requires high strength,
how can the Yield Strength of a material divided by its density, (σ/ρ) be of use to a
designer in the material selection process? (1.0 Marks)

2.4 c Which coefficient of friction, μs or μk is the most significant when your Team’s
compressed air engine first begins to operate from a stationary position? (1.0 Mark)

2.5 a The figure below is dimensioned in millimetres and represents a metal pin that is to be
inserted into a machined hole. Calculate the minimum and maximum amounts of
interference (include all units) and state with reasoning what type of fit it is. (3.0 Marks)

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2.5 b The figure below is dimensioned in millimetres and represents a part of a tool-steel
fixture. The designer is interested in ensuring that there is sufficient strength around the
major hole having a Ø40 +/- 0.02mm. One of the calculations requires knowing the
minimum value of the dimension ‘X’. Calculate the minimum value for dimension ‘X’
(include all units) (3.0 Marks)

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2.6 The figure below illustrates four (4) M6 Property Class 8.8 Grade bolts arranged as
shown subjected to a tensile force ONLY. Calculate the value of the force, F that the
four bolts are able to carry at the point at which yield failure occurs (include all units)
(4 Marks).




2.7 a The front spindle axle for a bicycle is shown in the figure below. Identify two distinct
manufacturing methods that have been used in its manufacture by, naming them and
briefly discussing how they would have been carried out. (2 * 2.0 Marks = 4.0 Marks).



2.7 b For one of the two methods you discussed in question 2.7a above, what is the best
surface finish that could be obtained, provide reasoning? (include all units) (1.0 Mark)
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2.8 A 0.75” (19.05mm) diameter shaft rotating at 500 RPM, with a radial load “P” equal to
112.4 lbf (500N) acting radially is supported by a bush with an outer diameter equal to
1.0” (25.4mm) and a length equal to 1.5” (38.1mm). Ignoring the weight of the shaft:

2.8a Calculate and then select the most appropriate material for the manufacture of the bush,
explain your reasoning. (2.0 Marks)

2.8 b What is the maximum speed possible using this material (in m/s)? (2.0 Marks)


Possible useful data:
1 inch = 25.4mm
1 pound-force (lbf) = 4.448 Newtons
1 newton = 0.2248 pound-force (lbf)
1 pound per square inch (psi) = 6,896.55 Pascals
1 Pascal = 0.000145 pounds per square inch (psi)
1 foot = 12 inches = 304.8mm
1 meter/sec = 196.9 feet/min
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2.9 Answer the following questions that are related to the Detail Drawing shown below. All
dimensions are in millimetres. State all units if required. (10 * 0.5 marks = 5 marks in total).

a. Which Projection Angle has the figure been draw in?
b. What is the value of dimension “A”?
c. What is the area of side “Y”?
d. What is the value of dimension “B”?
e. How many surfaces are machined (excluding tapped holes)?
f. How many holes require drilling and tapping?
g. What is the value of angle “L”?
h. What is the value of dimension “H”?
i. What is the value of dimension “D”?
j. What is the length of line “X”?
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2.10 A cylindrical pressure tank that is 1m in length and is 0.5m in outer diameter has a
thickness of 5.0mm. If the pressure inside the tank is 200 kPa, determine (include all units
and show working):
a. Is the pressure tank a thin or thick walled pressure vessel, explain your reasoning?
(2.0 Marks)
b. What is the Hoop stress? (2.0 Marks)

c. What is the Longitudinal stress? (2.0 Marks)

d. If the pressure vessel is to be manufactured from mild steel with a yield point of
350MPa, what is the Factor of Safety on the pressure tank design for both the Hoop and
Longitudinal Stress? (2.0 Marks)
e. Ignoring the Factor of Safety, what is the maximum pressure that the pressure vessel
can withstand before it ruptures? (2.0 Marks)


2.11 a. A solid flywheel has a mass of 200kg and an outer radius of 650mm. Calculate the
torque required to accelerate if from rest to 300 revolutions per minute in 60 seconds.
(2.0 Marks)
2.11b If the solid flywheel is to be manufactured from mild steel, what width should the
flywheel be manufactured to weigh the required 200kg? (include all units) (2.0 Marks)





END OF QUIZ