Ahmet Alp Gündüz - 030060034 - 4th Week

Sand Casting

Sand casting is by far the most widely used casting process, accounting for a significant majority of the total tonnage cast. Nearly all casting alloys can be sand cast; indeed, it is one of the few proceses that can be used for metals with high melting temperatures, such as steels, nickels and titaniums. Its versatility permits the casting of parts ranging in size from small to very large and in production quantities from one to millions. Sand casting consists of pouring molten metal into a sand mold, allowing the metal to solidify and then breaking up the mold to remove casting. The casting must then be cleaned and inspected and heat treatment is sometimes required to improve metallurgical properties.

(M. Groover, Fundamentals of Modern Manufacturing; Page: 215)

Automated Flow Lines

Automated production line consists of automated workstations connected by a parts transfer system whose actuation is coordinated with the stations. In the ideal, no human workers are on the line, except to perform auxiliary functions such as tool changing, loading and unloading parts athe beginning and end of line and repair and maintenance activities. Modern automated lines are integrated systems, operating under computer control.

(M. Groover, Fundamentals of Modern Manufacturing; Page: 930)

Infinite Life Design

Unlimited safety is the oldest criterion. It requires local stresses or strains to be essantially elastic and safely below the pertinent fatique limit. For parts subjectedto million cycles, like engine valve springs, this is still a good design criterion. However, most parts experience significant variable amplitude loading and the pertinent fatigue limit is difficult to define or obtain. In addition, this criterion may not be economical or practical in many design situations. Expamles include excessive weight of aircraft for impracticality and global competitiveness for cost effectiness.

(Ralph I. Stephens, Metal Fatigue in Engineering, 2nd Edition; Page: 23)

Safe Life Design

The safe life must include a margin for the seatter of fatgue results and for other unknown factors. The calculations may be based on stress-life, strain-life or crack growth relations. Safe life design may be based solely or partially on field and simulated testing. The margin for safety in safe life design may be taken in terms of life, in terms of load or by specifying that both margins must be satisfied.

(Ralph I. Stephens, Metal Fatigue in Engineering, 2nd Edition; Page: 23,24)

Eray Cavus 030060022 4th week

Human Engineering Design

The application of human engineering principles in the design of things which are to be used by people is not an exact science. Rather, it is a philosophy or an approach to problems of designing and constructing things which people are expected to use - so that the user will be more efficient and less likely to make stress in use of the article. In addition, it is an effort to make such articles more convenient, more confortable, less confusing, and, in the end, less exasperating or fatiguing to user

(Woodson W. E., Conover D.E.,Human Engineering Guide,Page 1-1)

Automatic Identification Systems(AIS)

Automatic identification systems are now being fitted to vessels, in accordance with thecarriage requirementsof the safety of Life at Sea Convention(SOLAS). Data to be provided automatically by AIS includes ship identification, ship type, and position, course and speed of vessel. As AIS can be used toadvantage for collision avoidance, such as determining identity another vessel and in more rapid detection of changes of heading, vessels maybe expected to make use of the equipment in appropriate circumstances. However, it shold be borne in mind when using AIS for collision avoidance that not all vessels are required to be fitted with AIS.

(Cockcroft A.N., Lameijer J.N.F., A guide to the collision avoidance rules: International Regulations for Preventing Collisions at Sea, Page 39)

Implicit features

Sufficient information is supplied to define the feature but the full geometric details have to be calculated when required.

As an example, consider a cylindrical blind hole. An explicit representation in a solid modeler will contain details of the cylindrical surface and the surface at the base of the hole, together with the equation of the edge curves. An implicit representation of the same hole might specify the center line, depth, and radius. The explicit information can be computed from the implicit data.

There are seven general features as follows:

-Circular through hole
-Circular pad
-Rectangular pad
-Rectangular packet with an interior rectangular boss with a blind hole
-Face(area to be plated)
-A bevelled edge
-A corner break

(Zhang H.C., Alting L.,Computerized manufacturing process planning systems, page 173-174)

Feature Mapping

At initial general design stage, design feature are gradually increase, but there are some uncertain factors and new structure of the design was not decided. Because some design features have been decided and the other were not decided at conceptual stage, we propose that the information of not deciding can be supposed in reason or ignored. Then the known design featurescan be mapped into the cost features with direct mapping,projective mapping, and conjugate mapping. For some parts that have been manufactured in the past detail cost estimation method is used directly to obtain the cost value.

(Jardim R.,Roy R.,Staiger A.,Advances in concurrent engineering, page 77-78)

Aycan PARLAK - 030060129 --- 4th Week

Close Die Forging

In closed or impression die forging, the starting forging stock is invariably a billet or bloom, since the weight and dimensions are usually critically. Upper and lower dies are contoured or sunk to form the required shape when the billet is inserted between them. The forging force may be supplied instantaneously, when the dies are closed over the billet, or more gradually when a hydraulic press is used. High forging pressures are required to make the material flow to fill the dies, and for even modestly sized forging such as automotive crankshafts, hydraulic or large mechanical presses are used. Since appreciable costs are involved in providing the dies, close die forging is more applicable to large production runs.(Edward G. Nisbett, Steel Forgings: Design, Production, Selection, Testing, and Application,

ASTM International,2009,p,25 )

Compound Die

In a compound die, as distinct from the progressive die, all the necessary operations are

carried out at a single station, in a single stroke of a ram. To do more than one set of operations,

a compound die consists of the necessary sets of punches and dies. During the part of stroke,

piercing of holes is done in the stock and upon further travel, the blanking operation is done.

( P. N. Rao, Manufactoring Technology:Foundry, Forming and Welding,

The McGraw-Hill Publishing, 1998, p.327 )

Isothermal Annealing

Isothermal annealing is derived from the exact knowledge of temperature-time diagrams.

This type of annealing is useful for softening steels for the subsequent machining operations.

This treatment consist of austenitizing at the normal annealing temperature (full annealing)

and then cooling rapidly to the appropriate temperature below Ar1, usually about 50-60 C below

Ar1(isothermal holding in pearlite range). This temperature held for a predetermined time,

enabling the complete austenite decomposition to take place for producing a structure having

optimum machinability. After the transmition is complete, the steel is cooled in a furnace,

or air-cooled, or rapidly cooled. (K. H. Prabhudev, Handbook of Heat treatment of Steels,

McGraw-Hill Pub., 1988, p. 50)

Automatically Programmed Tool (APT)

APT uses English-like language statements to define part shape and tool motion as well as

machine tool dependent data, such as feed rates and spindle speeds. This data is contained in an

APT part program. An APT processor program is used to read these statements, interpret the

meaning, and perform all the necessary calculations in order to generate a series of cutter

location points that define the cutter path. The APT processors a computer program which

runs on a mainframe computer, possibly at a central site with time-sharing facilities. The

generalized APT output is converted to the particular format G-Code required by the CNC machine

using a postprocessor program.(A. Alavudeen, N.Venkateshwaran, Computer Integrated

Manufacturing ,Prentice-Hall Pub., 2008, p.198)

Samet Türkmen-030060143-4th week

        Bezier curve:
  
        B ezier developed a reformulation of Ferguson curves in terms of Bernstein polynomials for the UNISURF System at Renault in France in 1970. 


         Degree elevation: The degree elevation algorithm permits us to increase the degree and control points of a B ezier curve from n to n+1 without changing the shape of the curve.
          
         Variation diminishing property
A polygon can be created by the segments connecting the ordered vertices of a B ezier
curve.
In 2D: The number of intersections of a straight line with a planar B ezier curve is
no greater than the number of intersections of the line with the control polygon. A line
intersecting the convex hull of a planar B ezier curve may intersect the curve, be tangent to
the curve, or not intersect the curve at all. It may not, however, intersect the curve more
times than it intersects the control polygon. 
In 3D: The same relation holds true for a plane.
Results : (a rough interpretation)
      A B ezier curve oscillates less than its polygon.
     The polygon's segments exaggerate the oscillation of the curve.
This property is important in intersection algorithms and in detecting the \fairness" of
B ezier curves.

(N. M. Patrikalakis, Massachusetts Institute of Technology  Cambridge, MA 02139-4307, USA, lecture 4 and 5, p.7)

      B spline:


  
The formulation of uniform B-splines can be generalized to accomplish certain objectives.
These include
-Non-uniform parameterization.
- Greater general flexibility.
- Change of one polygon vertex in a B ezier curve or of one data point in a cardinal (or
interpolatory) spline curve changes entire curve (global schemes).
- Remove necessity to increase degree of B ezier curves or construct composite B ezier curves
using previous schemes in order to increase degrees of freedom.
- Obtain a \local" approximation scheme.
The development extends the B ezier curve formulation to a piecewise polynomial curve with
easy continuity control.






(N. M. Patrikalakis, Massachusetts Institute of Technology Cambridge, MA 02139-4307, USA, lecture 6 , p.2)




      Phase change materials:

          There are two methods that can hold irregular shaped or curved workpieces in a medium other than hard tooling.In the first and older method.a low melting point metal is used as as the clamping medium.For example,an irregular shaped workpiee is dipped into molten lead and allowed to set.After setting, the solidified lead block is champed in a simple fixture.The possibly adverse effect of such materials as lead on the workpiece to be champed must be considered


          In the second method, the supportingmedium is magnetorheological or electrorheological fluid .In the MR application, the particles are ferromagnetic or paramagnetic micrometerin size as well as using nanoparticles, and in a nonmagnetic fluid.






(Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, 5th Edition,p.1177)





      Photopolymerization:


          
         Stereolithography process was used to polymerize SU-8 spun on the slides.This technology enables the fabrication of many complex shapes. The spectra physics model 2020 argon ion laser was used for irradiations. An exposure of 300mJ/cm^2 was required to properly manufacture quite vertical 30 micrometer height patterns. Matrix of regular polymeric wells was obtained by succesive duplications of an empty disc pattern inside a full polymer square,in the four directions. to get compact cross- linking, hatch pattern was performed every 100 micrometers and in the two ortogonal directions.

(Paulo Jorge Bártolo, Virtual and Rapid Manufacturing , p.348)

A. Selim PARLAKYİĞİT - 4th Week

1. Human Engineering Design
2. Phase-Change Materials
3. Photopolymerization
4. Automated Flow Lines
5. Automatic Identification Systems(AIS)
6. Vertical Integration
7. Product Focused Production Systems
8. Process Focused Production Systems
9. Control Charts
10.Quality-Assurance Inspection

Çağatay Taylan TAN 030070119 4th week

Extrusion
Extrusion operations are similar to plastic injection except that the product is continuous rather than discrete.The starting material and the methods for loading into the extrusion machine are basically the same as for injection molding.A pliable product can be collected in a coil, while a rigid one is usually cut the standard lengths.Either method can be automated to allow unattended operation of extrusion machines.

(Automation, production systems,and computer integrated manufacturing 3.edition ,Mikell P.Groover, p.385)

Computer Aided Maintanence
Computer aided maintenance depends on sensory systems to provide inputs for conditioning monitoring.Sensors can measure equipment performance and act like watchdogs to detect system faults and degradation.
(Computer aided maintenance methodologies and practises edited by Jay lee and Ben Wang,p.19)

Single Minute Exchange Die
Smed technology is a science developed by Shingeo Shingo and is designed to reduce changeover times.The proble is simple.Any machine that has long changeover times must have an excess capacity to account for the downtime of the changeover.Furthermore to supply the rest of the downstream process during the changeover a large batch must be stored up.Any effort to reduce the changeover times also reduce these two forms of waste ; excess capitalization and overproduction.In actuality ,the objecitve is to reduce the changeover time as much as possible.In some refined cases, the changeover is handled by having multiple fixtures on the same basic machine, and by simply throwing a switch the changeover is made.
The basic procude of SMED is simple , it is a three stage process :
1-Seperate internal from external setup
2-Convert internal setup to external setup
3-Streamline all aspecys of the setup operation

(How to implent lean manufacturing,Lonnie Wilson, p.69-70)

FLame Hardening
Flame hardening involves direct inplegement of oxyfuel gas from suitably designed and positioned burners onto the surface area to be hardened followed by quenching.The result is a hard surface layer of martensite over a softer interior core.There is no change in composition and therefore the flame hardened steel must have adequatecarbon content for the desired surface hardness.The rate of heating and the conduction of heat into the interior appear to be more important inestablishing case depth than the use of a steel of high hardenability.

(Surface hardening of a steels,Asm international, p.237)

Olcay Türkoğlu (2nd week unanswered terms)

Direct Labor: The labor directly involved in the manufacturing.(p. 1262) This labor spend his time to producing the part. A machine operator is an example for direct labor. (p. 1263)

Non-productive Labor: The personel involved in supervision, repair maintenance, quality control, engineering, research, sales and office are categorized as nonproductive labor. Because they do not contribute directly to the production of finished parts, or they are not chargeable to a specific product. p.1264

(Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, 5th Edition)

Oğuzhan Paçal, 030070031, 4th week

Laser cutting machine
Laser cutting machine controls the path of the laser that can cut through sheet metal, thus increasing the capability for producing a wide variety of shapes accurately, repeatedly, and economically, as well as eliminating the need for punches and dies. However, as expected, the surface produced by punching has different characteristics than that produced by laser cutting.

(Kalpakjian S. & Schmid S., Manufacturing Engineering and Technology, p.23)

Open Die Forging
Open die forging is the easiest forging process. Parts are simple shaped and mostly forged between two planar dies. This method generally used for rough shaping and forging before the close die forging.Also this method is more economical than closed die forging, and some big parts can only forged by open die forging.
(Manufacturing Methods Lecture Notes, A.Aran & M.Demirkol, p 4-2)

Deep Drawing
Deep Drawing is a process where the sheet metal gets the most basic shape for embossed materials.With deep drawing it is possible to get bathtubs, cylinder shaped containers, splash guards etc.To do that the sheet metal is cut to required dimensions with earlier process is taken and placed on a die then with a hammer (mostly press) it gets the required force. The die element that helps the process is called the pressure ring.
There are 3 types of forces are applied during the process

• Forming force required for deep drawing.
• Friction forces
• Ironing forces on the sheet metal
  

(Manufacturing Methods Lecture Notes, A.Aran & M.Demirkol, p 8-16)

Flat Rolling:
The process of reducing the thickness of a slap to produce a thinner and longer but only slightly wider product is commonly referred to as flat rolling. It is the most important primary deformation process. It allows a high degree of closed loop automation and very high speeds, and is thus capable of providing high-quality, close tolerance starting material for various secondary sheet-metalworking processes at a lw cost
Introduction to Manufacturing Processes, John A. Schey ,p 266)

Ozlem Salman (4th week)

Ozlem Salman (4th week)
1. Water jet machining
2. Laser cutting machine
3. Bezier curve
4. B- spline
5. Close die forging
6. Open die forging
7. Extrusion
8. Deep drawing
9. Flat Rolling
10. Sand casting

Özgür METİN, 030040004, 3rd Week

Use Value

Manufacturing adds value to materials as they become discrete products and are marketed. Because this value is added in individual stages during the creation of the product, the utilization of value analysis is important.

Use value reflects the functions of the product.

(Kalpakjian S. & Schmid S., Manufacturing Engineering and Technology, p.1266)

Esteem Value

Manufacturing adds value to materials as they become discrete products and are marketed. Because this value is added in individual stages during the creation of the product, the utilization of value analysis is important.

Esteem value (prestige value) reflects the attractiveness of the product that makes its ownership desirable.

(Kalpakjian S. & Schmid S., Manufacturing Engineering and Technology, p.1266)

Hundred-Percent Inspection

When inspection is conducted by humans, there is no guarantee that %100 of the defective parts will be found; because of fatigue and boredom, human inspection is only 80-85% effective.

(Schey John A., Introduction to Manufacturing Processes , p.897)

Direct Shell Production Casting

The Direct Shell Production Casting (DSPC) process, is similar to the 3DP process except that it is focused on forming molds or shells rather than 3D models. Consequently, the actual 3D model or prototype must be produced by a later casting process. As in the 3DP process, DSPC begins with a CAD file of the desired prototype.

Two specialized kinds of equipment are needed for DSPC: a dedicated computer called a shell-design unit (SDU) and a shell- or mold-processing unit (SPU). The CAD file is loaded into the SDU to generate the data needed to define the mold. SDU software also modifies the original design dimensions in the CAD file to compensate for ceramic shrinkage. This software can also add fillets and delete such features as holes or keyways that must be machined after the prototype is cast.

(Sandin Paule E., Robot Mechanisms and Mechanical Devices Illustrated, "Introduction" section p. xxvi)

Osman Selçuk Şahin 030060090 3rd week

Primitive instancing:The modeling system defines a set of primitive 3D solid shapes that are relevant to the application area.Primitive instancing is often used for relatively complex objects, that are tedious to define in terms of boolean combination of simpler objects, yet are readily characterized by a few high level parameters.In primitive instancing no provisions are made for combining objects to form a new higher level object.Thus the only way to create a new kind of object is to write the code that defines it.Similarly the routines that draw the objects or determine their mass properties must be written individually for each primitive.(James D. Foley, computer graphics: principles and practice,p:539)
International tolerance grade(IT):A group of tolerances that vary depending on the basic size but that provide the same relative level of accuracy within a given grade.(Edward G. Hoffman Christopher J: Mccauley,Shop reference for students and apprentices,p:223)
Present worth method uniform:For the life cycle cost analysis,present worth is the sum of all costs(and benefits) over the project life in today's dollars.It combines initial costs with discounted future maintanence costs,rehabilitation costs and a salvage value.The future costs are discounted to account for the time value of money using the discount(real interest) rate.Present worth analysis is limited to comparing alternatives with equal analysis period.(Tushar K. Ghosh,Mark A. Prelas,Energy resources and systems:Fundamentals and non renewable,p:55)
Annual cost method:Equivalent uniform annual cost spreads the cost of all items (initial startup costs,user fees,maintanence,and anticipated rehabilitation costs) annually over the life cycle of project.An analysis using equivalent uniform annual cost more effectively compares alternates with different service lives.However when making such comparisons the user must understand that during analysis it is assumed that the same set of activities will be repeated indefinitely.(Tushar K. Ghosh,Mark A. Prelas;Energy resources and systems:Fundementals and non renewable,p:55)

Osman Süzen 030060804 3 week

spindle: A spindle is a device that allows rotation between components whili providing three properties: stiffness, load capacity, and accuracy. Examples are found in machine tools, metrology instruments, and everyday conveniences like computer hard drives. rotation of rotor relative to the spindle housing (stator) is achived throught the use of one or more bearings, which include rolling element, externally pressurized by hydrostatic, hydrodynamic bearings. A spindle may be long and slender for high speed or low-profile such as rotary table. Or it may be a workpiece between centers or perhaps a gimbal, a knife- edge pivot, or a pair of trunnions intended for only a few degrees of rotation. Whatever the shape, a spindle has a rotor, a stator, and bearing in between. ( Eric Marsh - Precision spindle metrology- page 1 )

Job sequencing: Job sequencing is the seqyential assigment of jobs to work station and is also known as dispatching. To attempt to control the progress of a job through the shop, a job priority system is used. The priority of jobs queuing at work centre determines the order in which they are processed. The difficulty lies in determining an appropriate priority rule to obtain the best performance. Priorty rules include: DDS ( job with nearest customer due-date to the current date), FCFS ( job arriving first a work centre ), SPT (job with shortest process time) , LPT (job with longest process time) (Andrew Greasley-Operation management in business-page 138)

Finite-difference method: Finite difference methods have been proved to be useful technique for solving numerically sensitive two- point boundary value problems. This is due to the fact that the finite difference equations incorporate both specified initial and terminal conditions in the final set of equations, and thus the resulting solitions of these equation are constrained to satisfy these boundary conditions. This differs a shooting method, where the terminal boundary condition never enters into the solution during the forward integration process. Another difference is that the solution is produced simultaneously at all points, whereas in a shootingmethod the solution at different points are generated in seqyence. we may therefore expect the solitions near the terminal point to be less accurate than those obtained near the initial point because of the propagation of round-off errors. (T.Y.Na-Computational methods in engineering boundary value problems-page 133)

Direct data translator: Direct translation is the fastest method. this process uses a translator program that reads the input file, makes the appropriate translations, and then directly creates the output file. Because the program starts with a binary file and produces a binary file, it is the most efficient method. Unfortuantely, there are relatively few direct translator programs avaliable commercially, and these have been written for only the most popular CADD and GIS vendor formats. (George B. Korte-The Gis Book-page 237)

Selim Şen, 030060185, 3rd week

Shot Peening

In shot peening, the workpiece surfaces hit repeatedly with a large number of cast steel, glass, or ceramic shot(small balls), which make overlapping in dentation on the surface. This action causes plastic surface deformation, at depth up to 1,25 mm(0,025 in), using shot sizes that range from 0,125mm to 5mm (0,005in to 0,2 in.) in diameter.

Because the plastic deformation is not uniform through out to parts thickness, shot peening causes compressive residue stresses on the surface, thus improving the fatigue life of the component. This process used extensively on shafts, gears, spring, oil-well drilling equipments, and jet engine parts (such as turbine and compressor blades). (Kalpakjian, Smith; Manufacturing Engineering and Technology 4^th Edition; pg. 904)

Resolution

Resolution, also called sensitivity, is the smallest difference in dimension that the instrument can detect or distinguish. A wooden yardstick, for example, has far less sensitivity than finely graduated steel rule. (Kalpakjian, Smith; Manufacturing Engineering and Technology 4^th Edition; pg. 946)

Rule of 10

An instrument or gage should be 10 times more accurate than dimensional tolerances of the part being measured. (A factor of 4 is known as the Mil Standard rule). (Kalpakjian, Smith; Manufacturing Engineering and Technology 4^th Edition; pg. 961)

Acceptance Sampling

Acceptance sampling consists of taking only a few random samples from a lot and inspecting them to judge whether the entire lot is acceptable or whether it should be rejected or re-worked. Developed in the 1920’s and used extensively during WW2 for military hardware (MIL STD 105), this statistical technic is widely used valuable.

Acceptance sampling is particularly useful for inspecting high-production-rate parts where % 100 inspections would be too costly. There certain critical devices, however (such as pace makers, prosthetic devices, and components of the space shuttle), which must be inspected %100. (Kalpakjian, Smith; Manufacturing Engineering and Technology 4^th Edition; pg. 991)

ÖMER TAYLAN BOYA 030070099 3rd WEEK

CSG
In boundary representation B-Rep surfaces are combined to develop a solid model. In constructive solid geometry (CSG), simple shapes such as spheres, cubes, block, cylinders, and cones (called primitives of solids) are combined to develop a solid model.

(Kalpakjian, Smith; Manufacturing Engineering and Technology 5th Edition; pg. 1197)

GREEN ENGINEERING
Concerned with enviromental factors as in life cycle assesment, life cycle engineering deals in greater depth with design, optimization, and various technical considerations regarding each component of a product or process life cycle. A major aim of life cycle engineering is to consider reusing and recyling the components of a product from the earliest stage of discussing and considering the product design also called green design or green engineering.

(Kalpakjian, Smith; Manufacturing Engineering and Technology 5th Edition; pg.1245 )

FINITE DIFFERENCE METHOD

The Finite Difference Method (FDM) is based on the properties of Taylor expansions
and on the straightforward application of the definition of derivatives. It is probably
the simplest method to apply, particularly on uniformmeshes, but it requires the mesh
to be set up in a structured way, whereby the mesh points, in an n-dimensional space,
are located at the intersections of n families of lines and each point must lie on one,
and only one, line of each family.

Charles Hirsch Numerical Computation of Internal and External Flows (Second Edition) PG145

RECYCLING

Once a waste is eventually generated, there are two basic options recycling and
disposal. Recycling represents actions that manage in a way that results in using the
materials making the waste as feed stocks for some product or an application distinct
from disposal. This is done by segregating waste at source or by extracting materials
from it by various techniques, physical, chemical, thermal or biological.


(Resource recovery and recycling from metallurgical wastes Rao, S. Ramachandra Amsterdam ; London : Elsevier, 2006 PG.1)

OPTICAL DETECTORS

Before any evaluation of the information that the received light carries can start, it has to be transformed into electrical signals. All processes in which light incident onto a surface produces a current or a voltage are therefore processes around which optical detectors can be designed. The most important of these processes is the photoeffect upon which the working principles of different types of detectors are based.

(Jörg Haus, Optical sensors : basics and applications, Weinheim : Wiley-VCH, c2010 pg27)

Cemre Ablay 030060150 Third Week

Custom Part

Custom components, which are parts designed especially for the product, are made by the manufacturer or by a supplier. Most custom components are produced using the same types of production processes as standard components (e.g., injection molding, stamping, machining); however, custom parts are typically special-purpose parts, useful only in a particular manufacturer’s product.

(Kalpakjian S., Schmid S.R.,Manufacturing engineering and technology, 5th Edition, p. 217)

CNC Welding

CNC welding machines allow complete control of welding amps, wire feed, welding feed rate and torch height. Consistent welds can be made from part to part. Once you have made a part and made the necessary adjustments on the first run, the machine will consistently weld the same seam the same way from then on. Because the control can store thousands of welding part programs, you will get the same performance results when you return to make another run of the same part months later.

(Brink C., McNamara B., Engineering Fabrication-Sheet Metal Work, p.153)

CNC Milling

CNC milling machine or machining centres are computer-operated milling machines. If you compare a conventional milling machine to a CNC machining centre, you will be able to identify the same components such as the chuck, the cutting tool and the bed. The only real difference between a CNC machining centre and a milling machine is that the CNC machining centre has a computer control.

(Brink C., McNamara B., Engineering Fabrication-Sheet Metal Work, p.151)

Raw Material

Raw materials are unprocessed extractive or agricultural products - for example, mineral ore, timber, wheat, corn, fruits, vegetables, and fish. Raw materials become part of finished products. Extensive users, such as steel or lumber mills and food canners, generally buy huge quantities of raw materials. Because there is often a large number of relatively small sellers of raw materials, none can greatly influence price or supply. Thus, the market tends to set the price of raw materials, and individual producers have little pricing flexibility.

(Lamb, Hair, McDaniel, Marketing 10e, p.218)

Alpay Teoman YILDIZ - 030050014 - 3rd week

Affinity Diagram:

An Affinity Diagram is a tool that gathers large amounts of language data (ideas, opinions, issues) and organizes them into groupings based on their natural relationships.  The Affinity process is often used to group ideas generated by Brainstorming.

Basic Tools for Process Improvement, Module 4, p.2

Kano Diagram:

The Kano diagram is a well proven concept. It is a model of what prompts customers to select one product or service over another.

The Kano Diagram, Rewhorn, M. p.4

Construction Costs:

Some of the factors underlying construction cost trends are straightforward -such as sharp increases in materials cost- while others are complex, and sometimes less transparent in their impact. Moreover, the recent rise in many  utility construction cost components follows roughly a decade of relatively stable (or even declining) real  construction costs, adding to the “sticker shock” that utilities experience when obtaining cost estimates or  bids and that state public utility commissions experience during the process of reviewing applications for  approvals to proceed with construction.

Rising Utility Construction Costs, Chupka M.W., Basheda G., p.1

Preventive Maintenance Costs: 

1- Computers & Instrumentation

2- Software

3- Staff

Justifying Predictive Maintenance, Nichol R., p.4

Emre Ayaroglu - Unanswered terms ( 2nd week)

Cost Reduction

Cost reduction requires a study using relative costs as an important parameter. The unit cost of a product can vary widely. Unless highly automated, assembly operations for such products can become a significant portion of the overall cost.Cost reductions can be achieved by a thorough analysis of all the cost incurred in each phase in the manufacture of a product. Some opportunities for cost reduction are following:

- Simplifying part design and the number of subassemblies required.
- Specifying broader dimentional tolerances and allowing rougher surface finish.
- Using less expensive materials
- Investigating alternative methods of manufacturing
- Using more efficient machines and equipment(Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, 5th Edition, pg. 1265)

Random Sampling

Taking a sample from population or lot in which each item has an equal chance of being included in the sample. Thus, when taking samples from a large bin, the inspector should not take only those that happen to be within reach (Kalpakjian S., Schmid S.R., Manufacturing engineering and technology, 5th Edition, pg. 1121).

Emre Ayaroglu - 3rd week

1- Affinity diagram
2 -Kano diagram
3- Construction cost
4- Operator personnel cost
5- Preventive Maintanence cost
6- Assembly planning
7- Primitive instancing (Type of solid modelling)
8- Spatial Occupancy Enumeration (Type of solid modelling)
9- Direct shell production casting (Rapid prototyping method)
10- Integrated Product Development

Hüseyin DEMİRTAŞ__ 2nd Week UNANSWERED TERMS

Order Management Process


This process includes all the activities between the order acceptance and the customer payment. The major goals are to reduce the process lead time and cost, and to increase the customer satisfaction. Several business functions are involved in performing activities related to the order management process . Information technology can enhance the activity and resource coordination and facilitate communications. Among the different applications that can support the process, multimedia, electronic marketplace, and market analysis and forecasting at a microlevel are the most promising.
(Vito ALBINO, O. Geoffrey OKOGBAA, COMPUTER-AIDED DESIGN, ENGINEERING, AND MANUFACTURING Systems Techniques And Applications, p 11)


Production Process


This process is related to all the activities that transform raw materials in finished products. It has strong interdependencies with engineering, logistics, and order process. Company performances in terms of cost, time, and quality are affected by the coordination level in all manufacturing activities. The major issue is how to create a flow of products without defects and synchronized with the customer request. Manufacturing system layout (for instance, cellular manufacturing), process technology, planning and control techniques, and computer-aided manufacturing applications can enhance performance. However, in several cases (Schonberger 1982 and Womack et al. 1990) the most important benefits have been achieved by modifying work organization through simplification and waste elimination. Also, teams have shown to be highly effective to increase worker commitment and reactive response to problems (Cutcher-Gershenfeld et al. 1994). These characteristics are essential to improve flexibility and productivity.
(Vito ALBINO, O. Geoffrey OKOGBAA, COMPUTER-AIDED DESIGN, ENGINEERING, AND MANUFACTURING Systems Techniques And Applications, p 11)





Global Manufacturing Planning and Control


The last two decades have been characterized by the growing globalization of economic and social scenarios. In particular, multinational corporations (MNCs), due to their global market, have been experimenting a tight competition taking the advantage of their contemporary presence in different countries (Porter 1990). Companies could better achieve the exploitation of these advantages by the coordination of a network of geographically dispersed subsidiaries. The coordination may concern some as well as all the value chain activities, such as research and development, product and process design, engineering, marketing, supply, manufacturing, distribution, and so on. Global manufacturing planning and control refers to the problem of coordinating a MNC’s manufacturing activities. Since such manufacturing activities involve the entire network made up of the MNC’s subsidiaries, coordination should extend to the global supply network and distribution channels and it must also deal with the attendant logistics issues. Specific problems and techniques related to the synchronization of production rate with demand rate in global manufacturing are reviewed by Pontrandolfo and Okogbaa (1997).
(Vito ALBINO, O. Geoffrey OKOGBAA, COMPUTER-AIDED DESIGN, ENGINEERING, AND MANUFACTURING Systems Techniques And Applications, p 38)

Gani Can Öz - 2nd Week Unanswered Terms

Euro Emission Standarts

The European Union is introducing stricter limits on pollutant emissions from light road vehicles, particularly for emissions of nitrogen particulates and oxides. The Regulation also includes measures concerning access to information on vehicles and their components and the possibility of introducing tax incentives.

In order to limit pollution caused by road vehicles, this Regulation introduces common requirements for emissions from motor vehicles and their specific replacement parts (Euro 5 and Euro 6 standards). It also lays down measures improving access to information on vehicle repairs and promoting the rapid production of vehicles in compliance with the provisions of the Regulation.

Regulation (EC) No 715/2007 of the European Parliament