MEE 863 Advanced Manufacturing Technology
(3 Units)
Basic metal removal processes. Introduction to the mechanics of the processes. Economics of simple
processes. Introduction to machine selection, flexibility, and automation. Organization of
manufacturing, process planning, group technology, facilities layout, and production scheduling.
Question 3 (a) and (c)
3a) In conventional metal cutting process, tool wear is inevitable. Discuss the most significant
factors that cause tool wear.
3c) a steel ring of outside diameter 600mm and inside diameter 200mm is being faced on a
vertical CNC lathe. The machine is capable of maintaining a constant surface speed, as the face
of the ring is being machined and the feed-rate is set to 0.25mm/rev. From Tests, when
v=50n/min, Tool life is 60min n=0.3. Given Taylor empirical tool life relationship, VT=C.
Determine the number of components that can be machined per tool for a tool life of 50mins.
Pages 20 to 32
Page 24 (Machining)
Question One
a) Differentiate between milling and turning operations.
b) A lathe performs a turning operation on a work piece of 6in diameter. The shear strength
of the work=40,000lb/in2. The rake angle of the tool =10o. The machine settings are:
rotational speed=500rev/min, feed=0.0075in/rev. and depth=0.075in. The chip
thickness after the cut is 0.015in. Determine: (a) the horsepower required (b) the unit
horsepower for this material, (c) the unit horsepower with the correction factor (1 for
to=0.01in.) Use the orthogonal model.
Question Two
a) What is “manufacturing” in the context of engineering production? Also, define
manufacturing system.
Manufacturing could be defined as the making of products from raw materials using
various processes, equipment, operations and manpower according to a detailed plan
that is cost-effective and generates income through sales, while manufacturing system
is a system in which raw materials are processed from one form into another, known as
a product, gaining a higher or added value in the process and thus creating wealth in
the form of a profit. Or it could be seen as an integrated combination of processes,
machine systems, people, organizational structures, information flows, control systems
and computers whose purpose is to achieve economic product manufacture and
internationally competitive performance.
Basic Manufacturing system
b) List four common characteristics of manufacturing systems.
Four common characteristics of manufacturing systems are:
1. All systems will have specific business objectives to meet in the most cost-effective
manner.
2. All systems consist of an integrated set of sub-systems, usually based on functions, which
have to be linked according to the material processing.
3. All systems must have some means of controlling the sub-systems and the overall system.
4. To operate properly, all systems need a flow of information and a decision-making process.
c) As a manufacturing engineer, what skills and knowledge must one possess in order to
be successful as a process planner?
In order to be effective in the role of a process planner, the manufacturing engineer must
possess a variety of skills and knowledge. These have been identified as:
(i)
an ability to interpret engineering drawings;
(ii)
knowledge of materials for manufacture;
(iii) knowledge of manufacturing processes;
(iv)
knowledge of jigs and fixtures;
(v)
an ability to use reference material, for example, manufacturers, machining data,
tooling data, etc.;
(vi)
knowledge of the relative costs of materials, processes and tooling;
(vii) an ability to calculate manufacturing parameters and costs;
(viii) knowledge of inspection/QA procedures and specifications.
d) List ten (10) conventional metal removal processes known to you.
Question
a) What role does “process planning” play in the manufacture of a given product?
For an organization to manufacture a product that meets the design specification, the
manufacture of each component part of the product must be thoroughly planned. However,
merely ensuring that the product meets the design specification and is of the required quality
is not enough. The manufacture of the product must be cost-effective, that is, maximize the
added value, and meet the agreed deadlines, that is, be completed on time. Therefore, through
process planning the manufacturing engineer is responsible for ensuring that the product is
manufactured to the correct specification, at the lowest possible cost and completed on time.
b) Graphically illustrate the processes involved in the design and manufacture life cycle.
Question
a)
During turning a ductile alloy by a tool of γ0= 10o, it was found that Pz= 1000 N, Px = 400 N,
PY= 300 N and ζ = 2.5. Evaluate, using MCD, the values of F, N and μ as well as Ps and Pn for
the above machining.
Force Pxy=
Pz= 1000N Px