Nota MPD_12017_v2

DEM5222 MECHATRONICS PRODUCT DESIGN

TAJUK 1: INTRODUCTION TO PRODUCT DESIGN

1.1 Mechatronic design in products

Menurut kamus Dewan Bahasa reka cipta membawa maksud penghasilan suatu produk atau

barangan baru atau pengubahsuaian sesuatu produk yang sedia ada, bagi memenuhi kehendak

pengguna masa kini dan akan datang. Proses reka cipta berasaskan kepada gabungan tiga

konsep iaitu minda, kemahiran serta sikap atau nilai. Ketiga-tiga konsep ini digabung jalin bagi

menyelesaikan sesuatu masalah dengan melaksanakan aktiviti pencetusan idea, diterjemahkan

ke dalam bentuk ilustrasi dan dihasilkan semula dalam bentuk prototaip atau model. Bidang

rekabentuk melibatkan pelbagai bidang seperti elektronik, mekanikal, sistem kawalan, sains

komputer, senireka, bahan dan sebagainya. Rekabentuk produk adalah aktiviti paling penting

kerana dianggarkan 70% ke 80% daripada kos pembikinan dan pengilangan produk dapat

dikenal pasti pada peringkat permulaan sesuatu produk.

Sistem mekatronik terdiri daripada 4 elemen iaitu Sensor, Actuator, Controller, Mechanical

component

Produk baru dihasilkan akibat

• Dorongan permintaan –pengguna memerlukan ciptaan baru untuk menyelesaikan

sesuatu masalah

• Perubahan teknologi – penghasilan atau penemuan teknologi baru mencetuskan

permintaan produk baru.

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1.2 Integrated design issues in mechatronic

Considered systems consist of subsystems of different physical nature (mechanics,

electrotechnics, electronic, control including software). The subsystems operate

independently with limited interactions.

• system is partitioned into individual homogenous subsystems according to the

disciplines,

• homogenous subsystems are designed by specialists from a design team,

• each homogenous subsystem is designed by traditional way,

• each product function is from the most part realized by only one homogenous

subsystem,

• interactions are minimized, emphasis is mainly laid on common interfaces of the

subsystems.

A common approach is as follows: first the mechanical parts are designed (skeleton)

followed by electrical systems (muscles), electronic systems (sensors and nervous system)

and finally a control system (brain). A resulting system that appears to be mechatronic is

only a result of application of existing solutions and corresponding technologies. Research

and development of new technologies and/or solutions is not needed if the traditional

methodology is used.

Mechatronics uses the control systems in providing a coherent framework of component

interactions for system analysis. The integration within a mechatronical system is

performed through the combination of hardware (components) and software (information

processing). Hardware integration results from designing the mechatronical system as an

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overall system and bringing together the sensors, actuators, and microcomputers into the

mechanical system. Software integration is primarily based on advanced control functions.

Mechatronical systems result in shorter developmental cycles, lower costs, and higher

quality. Mechatronic design supports the concepts of concurrent engineering. In the

designing of a mechatronic product, it is necessary that the knowledge and required

information be coordinated among different expert groups. Concurrent engineering is a

design approach in which the design of a product and manufacture of a product are merged

in a special way. Traditional barriers between design and manufacturing are removed

The mechatronic design methodology is concerned not only with producing high quality

products but with maintaining them as well, an area referred to as life cycle design.

• Delivery: Time, cost, and medium

• Reliability: Failure rate, materials, and tolerances.

• Maintainability: Modular design.

• Serviceability: On board diagnostics, prognostics, and modular design.

• Upgradeability: Future compatibility with current designs.

• Disposability: Recycling and disposal of hazardous materials

Rujukan:

1. http://www.umt.fme.vutbr.cz/ESF/files/opory/design_of_ms_zkraceno.pdf)

2. http://www.slpk.sk/eldo/2005/010_05/13.pdf

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1.3 Mechatronic design process

The mechatronic design process consists of three phases:

• Modelling and simulation: A first principle model is a simple model that captures some

of the fundamental behaviour of a subsystem. A detailed model is an extension of the

first principle model providing more function and accuracy than the first-level model.

Complex models may be created by connecting the modules, or blocks, together. Each

block represents a subsystem that corresponds to some physically of functionally

realizable operations that can be encapsulated into a block with input/output limited to

input signals, parameters, and output signals.

• prototyping and

• deployment

The mechatronic design approach also uses a model-based approach, relying heavily on

modeling and simulation; however, unmodeled errors are accounted for in the prototyping step.

Their effects are absorbed into the design, which significantly raiser the probability of

successful product deployment. In the prototyping step many of the noncomputer subsystems

of the model are replaced with actual hardware. Sensors and actuators provide interface signals

necessary to connect the hardware subsystems back to the model. The resulting model is part

mathematical and part real.

Rujukan:

http://www.tesla-institute.com/index.php/using-joomla/extensions/plugins/95-mechatronicsdesign-process-system

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Proses rekabentuk

Proses merekabentuk selalunya bermula apabila wujudnya keperluan atau masalah di dalam

kehidupan. Perekabentuk perlu merekabentuk atau mencipta alat yang dapat menyelesaikan

masalah tersebut. Pernyataan masalah biasanya didapati dari masalah yang berlaku di

persekitaran atau dari pelanggan, atau dari pihak pengurusan syarikat. Pernyataan awal masalah

mesti menerangkan dengan jelas dan ringkas serta tidak samar-samar apa yang perlu

direkabentuk. Idea awal untuk memperolehi maklumat mengenai projek ini ialah dengan

memerhati objek tersebut daripada penggunaan, reka bentuk dan saiz yang digunakan.

Maklumat ini membantu dalam mengubahsuai dan menghasilkan ciptaan baru yang berkaitan.

Kaedah pengumpulan maklumat dan data adalah seperti pembacaan dan rujukan, pengalaman

sendiri, lawatan, web, soal selidik, pemerhatian dan sebagainya. Hasil daripada kajian dan

analisis yang telah dibuat, perlu membuat satu pernyataan akhir masalah dan

pemilihannya.Setelah pemilihan penyataan masalah dipilih maka seseorang pereka mestilah

membuat kriteria produk atau ciptaan yang hendak dibuat. Kriteria ini dinamakan sebagai

Product Design Specification (PDS) atau Spesifikasi rekabentuk produk.

NOTA

Data ialah maklumat yang boleh membantu membuat keputusan seperti saiz yang menyatakan

spesifikasi terperinci iaitu panjang, lebar, tinggi, tebal dan ketelusan. Sumber untuk

mendapatkan data termasuklah katalog, lembaran spesifikasi pamplet dan panduan produk.

Produk design spesification (Spesifikasi rekabentuk produk)

Dalam penghasilan sesuatu produk, spesifikasi rekabentuk produk atau ‘Product Design

Specification (PDS)’ merupakan antara langkah terawal yang perlu diambilkira oleh

perekabentuk dalam merekabentuk produk baru. PDS merupakan satu lakaran dalam bentuk

peta minda tentang tujuan produk direka, fungsi dan ciri-ciri yang dimiliki oleh produk.

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Di antara Ciri-ciri PDS adalah seperti berikut:

Prestasi (Performance) Persekitaran (Environment) Penyelengaraan (Maintenance)

Sasaran kos pengeluaran (Target production cost) Persaingan (Competition)

Kuantiti (Quantity) Pembuatan/pengeluaran (Manufacturing) Saiz (size)

Berat (Weight) Aspek Estetik ( Aesthetics aspects) Bahan-bahan (Materials)

Takat hayat penggunaan produk (Product Life span) Ergonomik (ergonomic)

Piawaian dan spesifikasi ( Standard and specification) Pengguna (Customer)

Proses (process) Keselamatan (Safety)

Mutu serta kebolehpercayaan ( Quality and reliability)

• Pengguna – citarasa dan trend pasaran

• Prestasi – contoh: kelajuan, kekerapan penggunaan, jenis bebanan, sumber kuasa. Kos

meningkat apabila prestasi meningkat

• Ergonomik – kajian saintifik ke atas faktor kemanusiaan dalam suasana pekerjaan

bertujuan untuk menjamin keselamatan, kesihatan, keselesaan dan kepuasan pengguna.

• Keselamatan – standar d ISO, MS untuk menjamin keselamatan pengguna

• Kos – Kos optimum dan minimum tanpa menjejaskan kualiti produk

• Bahan pembuatan – pemilihan bergantung kepada kos produk, kualiti dan kuantiti dan

persekitaran.

• Proses pembuatan – bolehkah produk yang rumit dihasilkan?

• Saiz – saiz sesuai untuk proses pemasangan, penyelenggaraan, pengendalian,

pengangkutan??

• Ujian – menguji produk baru (ujian kekuatan, ujian cuaca dsb)

• Hayat penggunaan produk – digunakan berterusan atau berapa jam sehari?

• Kekangan syarikat – modal, kemudahan pembuatan, tenaga kerja.

• Kuantiti – mempengaruhi harga dan alat pemprosesan

• Penyelenggaraan – ease of access kepada bahagian yang perlu diselenggara, kerumitan

dan kos penyelenggaraan

• Persekitaran – kesan persekitaran terhadap produk (suhu, kelembapan, karat, habuk)

dan kesan produk terhadap persekitaran (pencemaran, kebisingan)

• Estetik – rupabentuk fizikal, warna, kemasan permukaan.

Pencetusan idea mereka cipta (Conceptualization )

Pencetusan sesuatu idea tidak wujud dengan sendirinya, memerlukan daya usaha daripada

pelajar itu sendiri sama ada berbentuk semulajadi atau terancang.

Pencetusan idea cara semulajadi

1. Lamunan atau berkhayal

2. Bakat (anugerah Tuhan kepada manusia)

3. Pengalaman

4. Secara kebetulan

Pencetusan idea cara terancang

1. Pemerhatian dan pengamatan

2. Penumpuan kepada teknik-teknik

pemikiran

• pemikiran Iogikal - vartikal

• analitikal

• kritikal

• intuitif

• sumbangsaran

• lateral

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Langkah 1: Kenalpasti dalam bentuk input dan output apa yang perlu dilakukan oleh

rekabentuk

Langkah 2: Kenalpasti fungsi-fungsi atau proses-proses utama yang perlu dilakukan oleh

rekabentuk

Contoh fungsi atau proses utama yang perlu dilakukan oleh rekabentuk:

Tukar Pusing Angkat

Tambah/kurangkan Bekalkan Pegang

Sambung/pisahkan Atur/susun Bersihkan

Pandu Ambil Letak

Buang Pindah Gerak/hentikan

Simpan Ubahbentuk Putar

Buka

Asingkan

Langkah 3: Penjanaan idea berdasarkan analisis fungsi

Kaedah carta morfologi

A morphological chart is a diagrammatic method to generate ideas and forms based on function

analysis. Method helps designers to explore design solutions and forms in a systematic manner.

The chart sets out the complete range of solutions and form alternatives for each sub-function,

which is then combined together into a final design and form. The outcomes of this method are

more likely to be additive forms.

Steps

1. List sub-functions and features that final product will consist.

2. Draw a matrix and list sub-functions on the left column of the chart.

3. Fill in the rows by generating sub-solutions for each sub-function.

4. Based on the design goals, choose one sub-solution from each row and combine them to

generate final solution.

5. Draw your final solution and generate more alternatives if necessary.

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Contoh:

handmixer

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Portable chair

Rujukan

http://thedesignsection.com/?p=524

http://4generate.blogspot.my/2012/12/concept-generation-of-portable-chair.html

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Penilaian dan pemilihan cadangan rekabentuk (Evaluation)

Pemilihan Rekabentuk perlu dilakukan dengan teliti. Rekabentuk yang menarik dan sesuai

mampu menjadikan produk berkenaan boleh bersaing di pasaran. Untuk menghasilkan projek,

kita perlu memilih lakaran yang paling sesuai berpandukan criteria reka bentuk yang

dilakarkan. Penilaian harus diberi bagi setiap reka bentuk yang dihasilkan dengan berpandukan

beberapa faktor utama iaitu;-

Ciri-ciri Menilai & Memilih Konsep Reka Bentuk

• Fungsi - projek yang dihasilkan akan berfungsi dengan berkesan

• Rupa Bentuk - projek yang dihasilkan perlu ada rupa bentuk yang sesuai & menarik

• Kesesuaian Bahan - guna bahan yang sesuai & mudah diperoleh

• Kaedah Binaan - guna kaedah yang sesuai & mudah

• Ketahanan - projek yang hendak dihasilkan mempunyai ketahanan penggunaannya

• Kos - kos binaan projek tidak terlalu tinggi

• Kemasan - projek yang dibina perlu ada kemasan yang sesuai dan menarik

• Keselamatan - projek mesti selamat digunakan

• Nilai Komersial - projek berpotensi untuk dipasarkan

Komunikasi rekabentuk (Communication of the Design)

Komunikasi memainkan peranan penting dalam bidang rekabentuk bagi menyampaikan

maklumat kepada pelanggan dan juga rakan sekumpulan. Kaedah komunikasi yang baik amat

perlu untuk ‘menjual’ idea dan ciptaan yang dihasilkan. Pembentangan persembahan lisan,

menghasilkan laporan dan pameran biasanya mengandungi perkara-perkara berikut:

• Lakaran

• Penilaian

• Pengiraan

• Lukisan

• Model CAD

• Pictorial drawing

• Maklumat yang terkumpul

• Penyelidikan pasaran

• Analisa kos

• Model kerja

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1.4 Safety in design

Safe design refers to the integration of hazard identification and risk assessment methods early

in the design process to eliminate or minimise the risks of injury throughout the life of a product

being designed. It encompasses all design including facilities, hardware, systems, equipment,

products, layout and configuration.

In order to manage work health and safety risks during the design stage, designers should

consider

• Physical design of a product.

• Work layout to reduce the possibility of hazards occurring in the workplace.

• Applying risk management principles to the design process to eliminate hazards that

may occur during operation.

• Designing work to minimise the risks to workers. Creating healthy and safe work

requires jobs and tasks be designed to accommodate the abilities, diversity and

vulnerabilities of workers, including those returning to work following injury or illness.

Rujukan

Safety in design. http://www.ghd.com/PDF/2012%20HP&D%20Asia%20-

%20Safety%20in%20Design%20-%20BARKER.pdf [23.01.2017]

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TAJUK 2: PROCESS SELECTION

2.1 Mechanical fastening

A fastener is a device that mechanically joins or affixes two or more objects together. In

general, fasteners are used to create non-permanent joints; that is, joints that can be removed

or dismantled without damaging the joining components.

Mechanical joining falls into two distinct groups:

• Fasteners:

o Non-permanent fasteners (they enable parts to be assembled and disassembled

repeatedly):

General fasteners: keys, pins, retaining rings (often associated with

shaft)

Threaded fasteners: bolts and nuts, screws, studs, setscrews

o Permanent fasteners: rivets

• Other fastening methods/integral joints: seams, crimps, snap-fits and shrink-fits.

Material and shapes

• Virtually any material in any shape can be joined by mechanical fastening

• Practical limitations come from being able to form holes - this limits the options for

ceramics and composites. Snap-fit joints are especially suitable for low stiffness

materials like polymers.

• Especially good for joining different materials (e.g. composite to metal).

• Joint quality is reliable and readily determined. However, mechanical joining usually

reduces fatigue life.

• Essential where two parts will move relative to each other (e.g. hinges for doors).

• The non-permanence of many fasteners is useful for products that may need

repair/maintenance or need access to the interior.

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Threaded fasteners / Pengikat berulir

Pengikat berulir merangkumi skru, bolt dan nat. Bolt dan skru adalah serupa dari segi bentuk

dan penggunaan. Ia mengandungi batang yang berukir dan kepala. Biasanya bolt dipasang

bersama dengan nat pada lubang yang sudah digerudi, Skru pula dipasang pada bahagian yang

sudah berlubang atau tidak berlubang. Nat ialah komponen berulir yang menjadi pasangan

kepada bolt. Pemasangan bolt dan nat biasanya akan menggunakan sesendal untuk

mengelakkannya menjadi longgar dan terbuka akibat gegaran.

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Bolt: a bolt has a head on one end and threads on the other end and it is paired with a nut.

Threaded fastener designed to pass through holes in mating members and to be secured by

tightening a nut from the end opposite the head of the bolt.

Screws: screws are used to join two mating parts together and similar to bolts, they have head

on one end and threads on the other end. Threaded fastener designed to be inserted through a

hole in one member and into a threaded hole in a mating member.

Studs

Pengikat tanpa kepala. Kedua-dua hujung berulir. Digunakan bersama nat untuk mengikat

komponen.

Setscrews

Setscrew does not have a head and is used to prevent rotation or movement between parts (such

as shaft and collar). It is driven through one member such that it will apply a compressive/

normal force on the other member.

Nut

Nat mempunyai ulir dalam dan digunakan bersama bolt atau stud

• Nat segi empat digunakan dengan bolt dalam kerja pemasangan umum.

• Nat heksagon digunakan dengan bolt atau stud dalam kerja pemasangan umum.

• Nat telinga digunakan di tempat yang tidak memerlukan tekanan kuat tanpa

menggunakan soket atau sepana.

• Nat kota digunakan bersama cemat belah untuk menahan nat terkeluar daripada bolt.

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Washers/sesendal

Washers are commonly used under the heads of bolts, screws and nuts. Flat washer is used to

increase the bearing areas of the head, and protect the material finish during assembly. The use

of washers also prevent the sharp corner of the hole into which the bolt or screw is being

inserted from biting into bolt head fillet where that can cause failure of the bolts during service.

Lock washers prevent loosening of screws and nuts by providing continuous friction.

Jenis anjal

Jenis rata

• Digunakan sebagai pengalas bolt, nat dan skru.

• Fungsi:

o Mengelakkan pengikat menjadi longgar akibat gegaran

o Mengelakkan permukaan bahan yang diketatkan menjadi rosak

o Mengagihkan beban yang digunakan ke kawasan yang lebih luas.

Rivets

Rivets are permanent fasteners.

• Solid rivets: consist of a cylindrical shank with a single head. When the shank is

inserted inside the hole, the other end of the rivet is deformed with a rivet gun.

• Pop rivets/blind rivets: the installation of pop rivets is easy, fast and does not require

access to both sides of the assembly. Pop rivets are tubular and are supplied with a

mandrel through the center. After the rivet is inserted into a hole drilled through the

parts to be joined, a tool is used to draw the mandrel into the rivet. This expand the

blind end of the rivet and then the mandrel snaps off. Such rivets are not capable of

supporting large loads.

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Kekunci

• Fungsi: mengunci aci dengan roda tenaga yang berpusing bersama-sama

• Kekunci woodruff: dikenali sebagai kunci setengah bulatan, Bahagian bawah kekunci

ini dimasukkan ke dalam alur kekunci pada aci dan bahagian atas ke dalam alur takal

supaya ia tidak tertanggal.

• Kekunci persegi: dikenali sebagai kekunci benam. Sebahagian kekunci ini dimasukkan

ke dalam alur kekunci pada aci dan bahagian lain ke dalam alur takal yang dicantumkan

• Kekunci cotter: digunakan untuk menghindari ikatan bolt, nat dan skru daripada

terbuka, contohnya pada brek dan tayar kenderaan.

Retaining rings/gelang penahan

• Digunakan pada alur atau ditekan pada aci.

• Pengikat separa kekal

• Memudahkan kerja memasang dan membuka komponen.

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Integrated fasteners

Rajah a: Module with four cantilever lugs

b. cover with two cantilever and two rigid lugs

c. separable snap joints for chassis cover

Rujukan

http://www-materials.eng.cam.ac.uk/mpsite/process_encyc/non-

IE/mechanical_fastening.html

https://www.boltdepot.com/fastener-information/Printable-Tools/Fastener-Basics.pdf

https://www3.nd.edu/~manufact/FME_pdf_files/FME3_Ch16.pdf

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2.2 Fabrication process

<Rujuk nota machine operation>

Cutting

The raw material is cut to size. Cutting is done by sawing or shearing; torching with hand-held

torches (such as oxy-fuel torches or plasma torches); and via numerical control (CNC) cutters

(using a laser, mill bits, torch, or water jet).

Forming

Forming is a process of material deformation. Forming is typically applied to metals. To define

the process, a raw material piece is formed by applying force to an object. The force must be

great enough to change the shape of the object from its initial shape. The process of forming

can be controlled with the use of tools such as punches or dies.

Rolling

Forging

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Extrusion

Drawing

Bending

Bending is done by hammering (manual or powered) or via press brakes and similar tools.

Modern metal fabricators use press brakes to either coin or air-bend metal sheet into form.

Bending produces a V-shape, U-shape, or channel shape along a straight axis in ductile

materials, most commonly sheet metal.

Punching

Punching is the act of a punch and a die forming a ‘scissor’ effect on a piece of metal to make

a hole in it. Obviously, the punch and die must be the same shape and size of the desired hole.

In some cases, the main piece of material is kept, as in when holes are added for fasteners. In

other cases, the piece that is removed is the desired product-this is called ‘blanking’.

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Machining

Machining is the process of removing unwanted material from the block of metal to get the

desire shape by using metal lathes, mills, magnetic based drills, along with other portable metal

working tools.

Assembling

Assembling (joining of the pieces) is done by welding, binding with adhesives, riveting,

threaded fasteners, or even yet more bending in the form of a crimped seam. Structural steel

and sheet metal are the usual starting materials for fabrication, along with the welding wire,

flux, and fasteners that will join the cut pieces.

Welding

Welding is a core activity in the fabrication factory. It is used to prepare joints for connection

on site and for the attachment of other fixtures and fittings. The welding process uses an electric

arc to generate heat to melt the parent material in the joint. A separate filler material supplied

as a consumable electrode also melts and combines with the parent material to form a molten

weld pool. The weld pool is susceptible to atmospheric contamination and therefore needs

protecting during the critical liquid to solid freezing phase. Protection is achieved either by

using an inert shielding gas, by covering the pool with an inert slag or a combination of both

actions. As welding progresses along the joint, the weld pool solidifies fusing the parent and

weld metal together.

The end products of other common types of metalworking, such as machining, metal stamping,

forging, and casting, may be similar in shape and function, but those processes are not classified

as fabrication.

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2.3 Finishing process

Finishing processes may be employed to: improve appearance, adhesion or wettability,

solderability, corrosion resistance, tarnish resistance, chemical resistance, wear resistance,

hardness, modify electrical conductivity, remove burrs and other surface flaws, and control the

surface friction

• Ensure a smooth surface, to improve appearance or to provide a protective coating

• To ensure reliable performance and prolonged service life of modern machinery, its

components require to be manufactured not only with high dimensional and

geometrical accuracy but also with high surface finish.

• The surface finish has a vital role in influencing functional characteristics like wear

resistance, fatigue strength, corrosion resistance and power loss due to friction.

• The finishing operations are assigned as the last operations in the single part production

cycle usually after the conventional or abrasize machining operations.

Grinding

Grinding is a most common form of abrasive machining. It is a material cutting process which

engages an abrasive tool whose cutting elements are grains of abrasive material know as grit.

These grits are characterized by sharp cutting points, high hot hardness, chemical stability and

wear resistance. The grits are held together by a bonding material to give shape of an abrasive

tool.

Application:

• Surface finishing

• Slitting and parting

• Descaling and deburring

• Stock removal/abrasive machining of flat and cylindrical surface

• Grinding and resharpening of tools and cutters

Lapping

Lapping is a gentle, final operation commonly used to microfinish flat or cylindrical surfaces,

to increase accuracy, correct minor surface imperfections, improve surface finish, and achieve

a close fit between mating surfaces. Oil-based fluid suspension of very small free abrasive

grains (aluminium oxide and silicon carbide) called a lapping compound is applied between

the workpiece and the lapping tool. The lap or lapping tool is made of soft materials like copper,

lead or wood. The lap has the reverse of the desired shape of the work part. It is pressed against

the work and moved back and forth over the surface. All lapping methods are done at low

speed.

Application:

Used to produce optical lenses, metallic bearing surfaces, gages and other parts requiring very

good finishes and extreme accuracy.

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Polishing

Polishing, or flexible grinding, is an intermediate, dimensionless step in the formation of a

finished surface. It is generally preceded by grinding with a solid abrasive wheel and followed

by buffing. A polished surface is accomplished by the cutting action of millions of small

abrasive grains adhering to an endless coated belt or flexible wheel as they wear away the

metal. The complete polishing sequence usually involves several steps, first to remove the

initial scratches and defects and then to gradually impart the final surface condition.

Buffing

Buffing is a finishing operation in which the abrasive grains are contained in a buffing

compound that is pressed into the outside surface of the buffing wheel while it rotates. Buffing

wheels, called "buffs," are often fabricated into a number of piles from a series of individual

fabric disks (linen, cotton, broad cloth and canvas). The buffing compounds may be manually

applied to metal products in the same manner as is outlined for polishing (i.e., solid bar

compound). The compound may be also be supplied to the wheel face in liquid form by using

a patented airless -spraying system. Buffing generally follows polishing and is usually the final

operation that is performed on a workpiece. Buffing removes negligible amounts of material.

A buffed surface is formed in two distinct steps: 1.) Cutting down and 2.) Coloring. During the

initial finishing stage of cutting down, minute scratches left by polishing and other surface

irregularities are reduced or entirely eliminated. It is during the final stage of buffing (coloring)

that the ultimate reflective, highly lustrous surface is produced.

Honing

Honing is a mechanical means of stock removal that uses spring loaded abrasive stones as the

cutting tool. The honing tool is given a complex rotary and oscillatory axial motion. Most

honing is done on internal cylindrical surface. The cutting tool may be composed of aluminum

oxide, silicon oxide, or in some cases diamond grains held together by a vitrified or organic

bond. Honing produces geometrically accurate forms by correcting various inaccuracies

remaining from previous operations, such as high spots, chatter marks, out-of-roundness, taper,

or deviations in axial straightness. Each minute scratch serves as an oil reservoir for lubricants,

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thus diminishing the possibility of wear on a workpiece in service by minimizing friction and

heat. The surface generated by honing is free of torn, smeared, or "burned" metal.

Superfinishing

Super finishing, also called micro finishing produces a controlled surface condition on parts

which is unobtainable by any other method. Superfinishing is an abrading process in which the

cutting medium for cylindrical work is a loosely bonded abrasive stick or stone. The process

consists of removing fragmented or smear metal from the surface of a dimensionally finished

part. Dimensional changes are principally limited to the removal of high spots. Superfinished

parts are bright and reflective with an undisturbed crystalline structure.

Magnetic abrasive finishing process

Rujukan

https://www.slideshare.net/palanivendhan/surface-finishing-process-50920156

http://www.mfg.mtu.edu/cyberman/quality/sfinish/processes.html

26


TAJUK 3: PRODUCT SUSTAINABILITY

3.1 Material selection

Perbandingan sifat bahan

3.1.1 Logam

Bahan logam

• Bahan yang berstruktur hablur dalam keadaan pepejal

• Kuat, kukuh, tahan lasak

• Pengalir haba dan arus elektrik yang baik

• Kebanyakan logam bersifat mulur dan boleh tempa

27


28


Logam ferus

Besi

tempa

Keluli

Besi tuang

Besi tulen

Sifat mekaniknya ialah kemuluran

Mengandungi KURANG DARIPADA 0.08% KARBON

Dihasilkan daripada campuran besi dan karbon

Dikelaskan kepada 2 jenis: Keluli berkarbon dan Keluli aloi

Keluli karbon

Komposisi kimia –

keluli karbon rendah mengandungi kandungan karbon sehingga 0.3%,

keluli karbon sederhana sehingga 0.8% dan

keluli karbon tinggi sehingga 1.4%

Keluli aloi

Merupakan gabungan keluli dengan logam lain

Mempunyai sifat mekanik seperti kekuatan dan kemuluran

Sesuai bagi produk yang direkabentuk untuk menerima bebanan, hentaman

dan tegasan yang tinggi.

Contoh keluli aloi: Keluli nikel, Keluli kromium, Keluli krom-nikel

Leburan logam cair yang dituang ke dalam satu bentuk acuan yang disediakan

Tidak semulur keluli dan sifat kebolehmesinannya amat baik

Aloi keluli yang mengandungi karbon dan silikon

Kandungan karbon adalah antara 2 hingga 6.67 % & kandungan silikon ialah

antara 1 hingga 3 peratus

Contoh: roda kereta api, batang paip

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Logam bukan ferus

- Mengalirkan haba

- Tahan karat

Timah

Aluminium

Kuprum

Logam lembut dan berwarna putih

Mempunyai rintangan karatan yang baik

Boleh ditempa dan ditukul menjadi kepingan yang sangat nipis dan boleh

ditarik menjadi dawai halus

Dialoi dengan logam plumbum untuk meghasilkan bahan pateri lembut

Dialoi dengan kuprum dan stabium (antimony) untuk menghasilkan piuter

Logam ringan dengan ketumpatan 1/3 daripada aloi keluli

Mempunyai sifat pengalir haba dan arus elektrik yang baik

Mempunyai sifat rintangan karatan yang baik

Boleh ditempa dan dibentuk dengan mudah (lembut)

Digunakan dalam industri pembinaan kapal terbang, peralatan memasak dan

bekas makanan.

Mempunyai sifat pengalir arus elektrik & haba yang sangat baik


Mudah dibentuk dan dimesin untuk menghasilkan produk

Berwarna perang, boleh dikimpal

Aloi

Merupakan campuran dua atau lebih bahan logam bagi menghasilkan logam baru

Mempunyai sifat mekanik yang lebih baik berbanding logam tulen

Digunakan sebagai perintang elektrik

Loyang

Gangsa

Aloi kuprum dan zink

Kombinasi terbaik untuk kekuatan & kemuluran: Komposisi 70% kuprum &

30% zink @ 60% kuprum & 40% zink

Contoh: pemantul cahaya lampu kenderaan, penggalas, sesendal, komponen

pam, alat perhiasan

Aloi kuprum dan timah

Megandungi fosforus antara 0.01 hingga 0.5% & timah antara 1 hingga 11%

Mempunyai kekuatan & keliatan yang tinggi


Contoh: Hab kipas kapal laut, bilah, duit syiling satu sen dan pegas

3.1.2 Bahan bukan logam

• Bahan yang tidak mengandungi unsur logam

• Penebat haba yang baik

• Contoh:

Getah: tayar dan hos

Seramik: kaca, batu simen & seramik kejuruteraan seperti dioksida dan karbida

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3.1.3 Komposit

31


3.1.4 Polimer

Bahan plastik atau polimer mempunyai molekul yang sangat besar, terbentuk terutamanya

daripada atom karbon dan hidrogen. Ia dihasilkan melalui tindakbalas bersama bahan yang

molekulnya kecil (monomer) untuk membentuk molekul yang sangat besar.

Jenis

• Plastik termoset: melebur/melembut apabila dipanaskan pada pertama kali, tetapi

kemudiannya terset untuk menjadi bahan keras dan tegar

• Plastik termoplastik: melembut apabila dipanaskan dan kembali memperoleh

ketegarannya apabila disejukkan

Plastik thermoset

Fenol-

Formaldehida

i. Dipolimerkan oleh satu siri tindak balas pemeluwapan untuk

menghasilkan struktur rangkaian

ii. Polimer tulen adalah legap dan berwarna putih susu

iii. Keberaliran terma yang rendah dan penebat elektrik yang baik

iv. Rintangan yang baik terhadap minyak, gris dan kebanyakkan

pelarut biasa

v. Contoh penggunaan: Palam, soket, suis elektrik, tombol dan

pemegang pintu

Poliester i. Pemeluwapan asid maleik dan glikol propilena menghasilkan ester

ii. Pemaut – silang antara molekul-molekul polyester tak tepu

menghasilkan struktur rangkaian yang tegar

iii. Digunakan sebagai bahan asas plastic bertetulang gentian kaca.

iv. Kegunaan lapisan poliester:

a. Rintangan haba – komponen pesawat dan bahagian

elektronik

b. Rintangan kimia – tangki, paip dan salur

c. Hentaman tinggi – topi keselamatan dan pengadang mesin

Amino-

Folmaldehida

i. Sebatian yang mengandungi amino (- ) diluapkan dengan

aldehida untuk membentuk polimer tegar

ii. Sebatian yang penting ialah urea dan melamina

iii. Urea – formaldehida (UF) digunakan untuk membuat penutup

botol, cawan, piring dan pinggan

iv. Melamin formaldehida (MF) mempunyai rintangan haba sehingga

95˚F

v. Kegunaan lain bahan perekat dan agen pengikat dalam acuan

pasir.

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Plastik termoplastik

Polietilena (PE) i. Dihasilkan dengan cara pempolimeran

ii. Ciri polietilena bergantung pada berat molekul dan strukturnya

iii. 4 jenis: Berketumpatan tinggi (HDPE)

Berketumpatan rendah (LDPE)

Berketumpatan rendah lelurus (LLDPE)

Berat molekul ultratinggi (UHMWPE)

iv. Contoh kegunaan: Botol, filem pembungkus, penebat kabel,

galas dan gear

Polistrene (PS) i. Sejenis polimer lut sinar yang mudah diproses dan murah

ii. Mempunyai kestabilan dimensi

iii. Rintangan tindak balas terhadap bahan kimia adalah rendah

iv. Digunakan untuk membuat bekas makanan, penyerak cahaya

dan permainan kanak-kanak

Polipropilena (PP) i. Sejenis polimer habluran tinggi

ii. Mempunyai kekuatan & takat melembut yang lebih tinggi

berbanding dengan polietilena berketumpatan tinggi (HDPE)

iii. Mempunyai kekuatan lesu yang tinggi

iv. Rintangan yang tinggi terhadap serangan bahan kimia

v. Digunakan sebagai kotak bateri, bahan pencuci hampa gas dan

komponen dalaman kereta

Polivinil klorida i. Mempunyai ketahanan yang baik terhadap asid dan alkali

(PVC)

ii. Keras dan tegur pada suhu biasa

iii. Digunakan untuk membuat lapisan panel, paip dan pepasangan

paip, rangka tingkap dan botol

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No two materials have the same properties and the choice is usually decided by the best possible

combination of material properties and economical factors which necessitates an optimum

solution.

a) Functional properties: The correct combination of mechanical, physical and chemical

properties to meet the function and operating conditions of the component.

b) Manufacturing properties: Processing or fabrication properties of the material for the

conversion processes needed to convert the material into required shape, such as ease of

casting, forming, joining, and machining.

c) Economics: Cost of the material as well as cost of processing the material into required

shape. As part of overall economics, both availability and recycling aspect should also be taken

into account.

34


Material selection involves a complex interaction between component function, material,

process, component shape and costs. The function of the component must be clearly defined in

order that the required mechanical properties may be identified. A process must be found that

is capable of making the component shape, with the correct accuracy, and with an acceptable

cost. It is also important that both the material and processes used must be controlled during

manufacture. For example, an incoming stock of raw material, which shows variations in

composition and microstructure, cannot be heat treated and machined easily. A sheet metal

showing variations in its cold worked condition will exhibit differences in ‘spring back’

characteristics during forming. A cast component may show inclusions and porosity unless

melting operation, mould filling and solidification of the casting are controlled. The final

functional or mechanical properties of a component, to a large extent, depend on the degree of

control it receives during its processing.

Rujukan

https://www.scribd.com/document/49846356/Bahan-Kejuruteraan

https://www.flipsnack.com/ichigo141/tugasan-kumpulan-4-bahan-bahan-kejuruteraan.html

http://www.stephensinjectionmoulding.co.uk/thermoplastics/

35


TAJUK 4: PRODUCT COSTING AND ESTIMATION

Kos produk terbahagi kepada dua kategori

• Kos langsung (Direct cost)

• Kos tidak langsung (Indirect cost)

Kos bahan (material cost): kos pembelian bahan untuk sesuatu produk termasuk kos bahan

buangan (scrap) dan produk gagal kecuali bahan buangan dapat dikitar semula (kos bahannilai

bahan kitar semula). Tiada kos bahan terlibat jika syarikat outsource/memberikan kontrak

kepada pihak luar untuk menghasilkan produk/komponen siap.

Kos pembelian komponen (purchased-parts cost): kos membeli alat atau bahan daripada

pembekal atau pihak luar seperti kos pembelian pengikat dan pembungkus.

Kos buruh (labor cost): kos pembayaran gaji, elaun, insurans, caruman dan sebarang faedah

kepada pekerja untuk menghasilkan produk

Kos perkakas (tooling cost): kos penyediaan perkakas pembuatan seperti jig, lekapan dan

acuan.

Kos pasti (overhead cost): kos pentadbiran, penyelidikan dan pembangunan (R&D),

kesetiausahaan, pembersihan bangunan, sewaan bangunan, bil dan lain-lain yang tetap dibayar

walaupun tiada produk dihasilkan.

Kos bolehubah (variable cost): kos bahan, buruh dan pembelian komponen yang berubah

mengikut bilangan produk yang dihasilkan. Semakin banyak produk yang dihasilkan semakin

rendah kos per produk.

Perbelanjaan penjualan (selling expenses): kos membiayai persediaan penjualan seperti

iklan dan promosi produk baru.

36


TAJUK 5: MODELLING TECHNIQUE

<Rujuk nota GEM1212 Engineering Drawing>

File Naming

Mode Extension Description

Part .ipt All part modelling, sketching and complex design takes

place on individual parts

Assembly .iam Parts are added to assemblies to position and constraint

them together to form a completed design

Drawing .idw atau

.dwg

Used to communicate the 3D design in a 2D format.

Views and annotations are used to document the design

Presentation .ipn Used to create explosions that are used to document

disassembled views in a drawing. Can be used to

animate tasks for visualization of component movement

37


Autodesk Inventor Interface

Model display

38


Measurement Tools

Model properties

By assigning a material, the physical properties of the model such as volume, mass and center

of gravity can be calculated. When the material is assigned the colour of the part changes to

the assigned material’s colour. If you want to assign a different appearance to the model

while maintaining the iproperty data, you can select an alternate material in the Appearance

Override dropdown list.

39


Modelling tools

Pembinaan bentuk-bentuk asas lukisan

a. Line: Garisan lurus berterusan di lukis melalui penentuan titik mula dan titik akhir

dengan menggunakan system koordinat mutlak, kutub atau bandingan.

b. Circle: Pembentukan bulatan boleh di lakukan dengan beberapa cara antaranya dengan

memberi nilai jejari atau garis pusat , bulatan antara dua titik ( 2P ) , bulatan antara tiga

titik ( 3P ) dan bulatan bersentuh ‘ tangen ’ antara dua objek lain.

c. Arc: Lengkung atau ‘ arc ’ ialah binaan bentuk sebahagian daripada bulatan yang boleh

di bina merujuk kepada format berikut dengan memberi gabungan tiga titik bergantung

kepada pemilihan-pemilihan seperti yang di tunjukkan dalam rajah di bawah.

40


d. Ellipse: ELLIPSE akan dibentuk berdasarkan gabungan segmen daripada

pembentukan garis poli (polyline ) dan lengkung ( arc ). Ellipse boleh dibina dengan

menentukan titik tengah, jarak minor, jarak major dan sudut putaran dari paksi .

Contoh-contoh pembinaan ellipse seperti berikut

Pembentukan elipse berdasarkan kedudukan titik antara paksi utama, paksi kedua dan

titik tengah ellipse

Pembinaan elipse di bentuk dengan menentukan sudut putaran paksi major

e. Polygon: Arahan POLYGON membolehkan pembinaan bentuk segi banyak yang

diwujudkan dari bentuk-bentuk muka tepi antara 3 hingga 1024 sisi. Segi banyak dibina

melalui penentuan jejari bulatan luar (jejari pepenjuru), jejari bulatan dalam (jejari

tangen) atau melalui penentuan panjang muka tepi.

41


Sketch constraints option

Contoh:

42


Sketch editing option

43


• Erase: Arahan ERASE (padam) akan memadam objek yang tertentu secara langsung

dari editor lukisan. Panggilan semula lukisan boleh dilakukan dengan arahan ‘oops’

• Copy: Fungsi COPY (salin) digunakan untuk menduakan satu atau lebih objek lukisan

pada lokasi atau tempat tanpa memadamkan objek asal.

• Array: Fungsi ARRAY (susun) membolehkan salinan berbilang objek atau objekobjek

terpilih dalam bentuk segi empat tepat atau polar.

Rectangular (segi empat tepat) – Masukkan bilangan baris tegak, baris datar dan jarak

antara baris apabila diminta.

Polar (kutub) – Pastikan titk dasar pusat telah ditentukan dan bekalkan maklumat

seperti bilangan objek yang perlu disalin, sudut yang perlu dipenuhi dan sudut antara

objek.

Circular pattern

Rectangular pattern

• Move: Fungsi MOVE (pindah) digunakan untuk memindahkan objek dari satu

kedudukan ke satu kedudukan lain tanpa melakukan pengubahsuaian terhadap saiz dan

bentuk objek. Objek kedudukan asal akan terpadam

• Rotate: Fungsi ROTATE (putar) membolehkan objek-objek yang dipilih diputar

sekitar sudut berasaskan titik dasar yang ditentukan. Angka sudut positif akan memutar

berlawanan arah jam sementara angka sudut negatif sebaliknya

• Mirror: Fungsi MIRROR (cermin) membenarkan objek-objek terpilih pada lukisan

dibalikkan sama ada dengan memadamkan objek asal dan meninggalkan objek akhir

(imej) atau mengekalkan bentuk objek asal dan imej (objek akhir) pada akhir arahan.

Kedudukan garisan pembalikan bersesuaian perlu ditetapkan.

44


Penentuan garisan pembalikan objek Pt1 dan pt2

Teks tidak diterbalikkan bersama objek apabila MIRRTEXT = 0

• Trim: Fungsi TRIM ( kemas) membenarkan objek-objek lukisan dikemaskan sehingga

tepat pada sisi yang disempadani oleh satu atau lebih objek lain

Kekemasan objek dengan arahan ‘trim’

• Extend: Fungsi EXTEND (rentangan) membenarkan objek-objek dipanjangkan tepat

kepada sempadan yang ditakrifkan sebagai satu atau lebih objek lain dalam lukisan.

Objek boleh bersambung dengan penggunaan arahan ‘extend’

• Chamfer: CHAMFER (serongan) berfungsi memotong dua garis bersilang dengan

jarak yang diberi dan meyambungkan kedua-dua hujung yang dipotong dengan satu

garis tambahan. Jika kedua-dua garisan ini tidak bersilang, fungsi CHAMFER akan

45


memanjangkan garisan objek sehingga bertembung menurut jarak serongan yang

diberi.

Garisan potongan akan dibentuk pada penjuru objek

• Fillet: FILLET (kambi) berfungsi menyambungkan dua garisan, lengkuk, atau bulatan

dengan satu sambungan lengkuk lengkap dengan panjang jejari yang ditentukan. Ia

akan menyesuaikan semula garis-garis asal supaya sempurna dengan bentuk yang baru.

Pembentukan kambi pada pepenjuru objek

• Offset: Fungsi OFFSET (offset) membentuk satu entiti yang selari dengan entiti yang

dipilih mengikut penentuan jarak atau titik tetentu. Objek – objek yang boleh di offset

adalah seperti garis, lengkuk, bulatan dan garis poli.

Garisan selari dibina menggunakan penetuan jarak (d) diantara objek

• Stretch: Fungsi STRETCH (regangan) membolehkan bahagian-bahagian terpilih

diregangkan tanpa mengubah keadaan sambungan bahagian objek. Jenis-jenis

persambungan yang boleh diregangkan ialah bentuk-bentuk terdiri daripada garis,

lengkuk, surihan, pepejal, garis poli dan garis 3D.

46


Objek diregangkan berdasarkan titik regangan yang dipilih

• Scale: Fungsi SCALE atau skala objek membenarkan saiz-saiz objek tersedia diubah.

Skala yang sama akan digunakan untuk kedua-dua dimensi pada paksi X dan paksi Y.

Gunakan faktor relatif lebih daripada 1 untuk membesarkan objek dan faktor relatif

antara 0 hingga 1 untuk mengecilkan.

Mengubah saiz objek dengan faktor skala

• Ltscale: Ltscale ( Line Type Scale –Skala Jenis Garis ) berfungsi mengawal secara

keseluruhan factor panjang sengkang jenis garis

Menunjukkan bentuk garisan tersembunyi (hidden) dari faktor skala garisan yang berbeza

47


3D Model

1. Features dependent on sketches

The models created by these operations are typically solid features, or new bodies that form a

closed volume.

Extrude

A feature created by adding depth to a sketched profile. Feature shape is controlled by profile

shape, extrusion extent, and taper angle.

48


Revolve

A solid feature created by revolving a profile around an axis.

Loft

A sketched feature specified by tangency condition, termination, and order of sketches. Loft

features blend 2 or more dissimilar sketch shapes on nonintersecting sketch planes.

49


Sweep

A feature created by moving a profile along a path. A sweep feature usually requires two

sketches, a profile, and a path on intersecting planes. An optional guide rail for scaling can be

included in a third sketch.

Coil

Projects a sketch profile along a helical path.

Use Coil to create springs or to model physical threads on a part.

Can create a body.

Surfaces

You can create surfaces with many of these operations. Surfaces can form an open or closed

volume but contain no mass. Use surfaces to define shapes, use as a split tool, or sculpt certain

aspects of the part body.

The following features require sketches, but do not create a base feature because they are

dependent on existing geometry.

2. Sketched features that are dependent on existing geometry

These features do not create a base feature because they are dependent on existing geometry.

Rib

Creates a rib or web extrusion from a 2D sketch.

Use Rib to create thin-walled closed support shapes (ribs) and thin-walled open support shapes

webs.

50


Emboss

Creates a raised (emboss) or recessed (engrave) feature from a sketch profile.

Decal

Applies an image file to a part face.

Use decal to add realism or to apply a label.

3. Placed Features

Placed features are common engineering features that do not require a sketch. The commands

for placed features (fillet, chamfer, hole, thread, face draft, and shell,) are located on the Sketch

and 3D Model tabs:

• Fillet: Places a fillet or round on selected edges loops, and features.

• Chamfer: Breaks sharp edges. Removes material from an outside edge and adds

material to an inside edge.

• Hole: Places a specified hole in a part, optionally with thread.

• Thread: Creates regular and tapered external and internal threads on cylindrical or

conical faces.

• Shell: Produces a hollow part with a wall thickness you define.

• Rectangular Pattern: Creates a rectangular pattern of features.

• Circular Pattern: Creates a circular pattern of features.

• Mirror Feature: Mirrors different type of features across a plane.

51


Hole

Shell

Draft

3D Assembly Drawing

How Joints Work

When components are brought into an assembly, they come in with six degrees of freedom

(DOF). When we apply constraints, we reduce those DOF based on the type of constraint we

apply and what geometry we select. For example, if we apply a mate-flush constraint, we

reduce the DOF of the component by two rotational and one translational. When applying a

joint, we are identifying how many degrees of freedom will remain after we apply it. So, if a

part starts with six DOF and we apply a rotational joint, we will only be left with one rotational

DOF — the ability to rotate around the axis specified.

52


Rigid

Cylindrical

Constraints the components in all DOF. Ex:

Welded or bolted connections

Enables a component to translate and rotate

about a specific axis.

Ex. The handle can rotate about the cylinder

and translate along the axis.

Rotational

Planar

Constraints a component to rotate about an

axis.

Enables a component to move in a plane.

The joined component can now move in any

direction relative to the plane and can rotate

about any edge or axis that is normal to the

plane.

53


Slider

Ball

Allows for translational movement along an

axis.

Can rotate in any direction

Applying Joints

We now know what joints are and what they do, but how do we apply them? Joints are applied

a little differently than we would apply constraints. Using the Connect selection buttons on the

Joints dialog (below, left) or the Joints mini-toolbar (below, right), we are able to select points

along faces or edges to establish the relationship between the components.

When you select a face, you can choose from any of the corners, the midpoints of any of the

edges, and even the center of the face to position the component. When you select a linear edge

you can pick from its endpoints and midpoint. When you select a circular edge or spherical

geometry, you can pick the center of the edge or geometry.As you would expect, you can also

Flip the direction of the selection and you can use the Align tools to adjust the orientation of

the components you are applying the joint to.

.

54


Some additional options for controlling joints are gaps and limits. Similar to offset for

constraints, Gap allows us to keep components a specified distance away from each other. Also

like constraints, we can apply limits to the angular and/or linear elements of a joint to specify

a range of motion for that joint.

Applying Constraints

Categories of constraints:

• Assembly – basic constraint used to constrain objects to proper orientation with respect

to one another by using surfaces, edges, planes, points and axes.

• Motion – used for components such as meshing gears or rack and pinions

Within the Assembly constraints tab, there are 4 types of constraints:

• Mate: positions two components adjacent to each other. Can be assigned between two

planes, surfaces, edges or points.

Note: to fully constrain an object so that it doesn't move using the mate option, you will

have to constrain it 3 times - 1 constraint each for the x, y, and z planes

55


• Angle: Used to specify the angle between two edges, planes or an edge and a plane of

the components. This constraint removes two rotational degrees of freedom

• Tangent: positions two components tangent to each other. This constraint removes one

translational degree of freedom.

• Insert: position two components to fit into each other. This constraint removes three

translational and two rotational degree of freedom by mating the axis of two

components, as well as applying a Mate constraint between two planar faces.

56


Offsets are used to specify the distance/angle between the two surfaces you are constraining

• For Mate, Tangent, and Insert: The offset will move the objects so that they are the

specified distance apart. Note: you can input a negative offset to move the object in the

opposite direction

• For Angle: The offset will angle your objects so that their planes are the specified

degrees apart from each other

Limits

Motion constraints:

• Two round objects – gears and pulley systems.Different approach with circles and

gears:

o With circles, you select the contact surface of the objects and the ratio is

automatically calculated using the diameters

o With gears, you select the hole of the gear and then enter the ratio of teeth

57


• A round and a flat object – rack and pinion systems

o Select the edge of the round object to highlight the rotational axis

o Select the REAR EDGE of the flat object

o Enter the distance that the linear object moves for each round object revolution

(circumference!)

Multiple assemblies can be combined to form a more complete assembly

Create a Bolted Connection

58


Inside the BCG, there are four ways to select how you want to position your fasteners: linear,

concentric, on point and by hole.

After selecting one of the four options, select the position of the fastener by going through the

placement steps to pick points, edges and planes on your assembly.

After you select the position, you can choose the type of fastener from the Content Center

Library, a library of standard parts representative of all industry standards such as ANSI, ISO,

DIN and the like.

The bolted connection has several key benefits. Having the luxury of placing and constraining

multiple parts at one time is critical for saving time. You can edit the connection by using the

Design Accelerator. You can access this function by highlighting the Bolted Connection in the

parts tree and right-clicking the mouse. When you choose Edit using the Design Accelerator,

the Bolted Connection Component Generator dialog box appears, and you can change the parts.

Rujukan:

• http://www.cadalyst.com/manufacturing/bolted-connection-generator-tool-avatechtricks-tutorial-11008

• http://apprize.info/software/autodesk_1/9.html

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TAJUK 6: PRESENTATION VIEW

Presentations are used to develop exploded views, animations and other stylized views of an

assembly to aid you in documenting your design, and animations can then be used to show the

step-by-step assembly of your design.

Control trail and tweak

To create a presentation view, click create view and choose either manual or automatic

explosion method.

Manual explosion method

• Direction: Select a plane or face to set the direction of translation or axis of rotation. A

direction triad displays on the plane. Select an axis on the triad to define the direction.

• Components: Select the component(s) to tweak

• Trail origin: Set the origin for the trail. If you do not specify the trail origin, it is placed

at the center of mass for the part.

• Transformations: Select the options to translate or rotate the component(s). Apply the

tweak by entering value (distance or angle) in the Distance/Angle field or by dragging

or rotating the component(s).

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Precise view rotation

This command enables you to control the angle of the view for the assembly (how you want it

to be displayed in a drawing file)

Capture camera

Once you use the viewing tools to adjust a presentation view, you can save that view as a

default by select Save Camera option. The Save Camera option saves the viewing angle, focal

length, and camera/target distance. It does not save the perspective/orthographic camera or

shaded/hidden edge/wireframe view.

Animate presentation and output animation file

Once you have created an exploded view, you can put the parts of the assembly in motion to

show how they fit together.

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TAJUK 7: PRODUCT DOCUMENTATION

Lukisan kejuruteraan adalah cara untuk menghasilkan lukisan pelan yang menggambarkan

dengan tepat sesuatu objek teknikal, seni bina dan kejuruteraan. Dengan kata lain lukisan

kejuruteraan merupakan alat komunikasi atau bahasa perhubungan di kalangan mereka yang

terlibat dengan dunia kejuruteraan.Ia adalah satu dokumen, dalam bentuk bergambar dan

sedikit nota. Ia mengandungi semua maklumat penting bagi tujuan pembuatan atau

pengilangan; iaitu mungkin mengandungi satu komponen tunggal, sebahagian kumpulan

binaan atau satu barangan lengkap yang menunjukkan keseluruhan komponen.

Secara teknikalnya lukisan kejuruteraan boleh dipecahkan kepada dua iaitu:-

1. Lukisan mesin; Iaitu lukisan pemasangan yang dikhususkan kepada proses mencantum

dan membuka komponen untuk memenuhi tujuan pembuatan, selenggaraan atau

persembahan.

2. Lukisan kerja; Iaitu lukisan yang menerangkan dengan terperinci bagaimana sesuatu

komponen itu harus dihasilkan dan apakah yang patut dicapai oleh sesuatu pengeluaran

itu. Lukisan ini juga menunjukkan sifat akhir sesuatu komponen. Lukisan ini

termasuklah Lukisan Terperinci, Lukisan Butir, Lukisan Bahagian-bahagian dan

Lukisan Pembuatan.

Lukisan Pemasangan

Lukisan pemasangan menunjukkan bahagian yang terperinci (detail parts) atau ‘subassemblies’

yang disambungkan bersama untuk membentuk komponen tertentu atau mesin. Lukisan

pemasangan digunakan untuk memastikan komponen yang berpisah menjadi satu produk bila

dicantumkan. Tujuan utama lukisan pemasangan adalah untuk menunjukkan kaedah

pemasangan komponen dilakukan. Ciri-ciri lukisan pemasangan adalah seperti berikut:

a. Setiap komponen dilabelkan dengan nombor yang dirujuk kepada senarai bahan

(BOM).

b. Nombor rujukan atau nombor siri lukisan boleh digunakan sekiranya rujukan perlu

dibuat kepada lukisan yang lain.

c. Lukisan keratan perlu disertakan untuk menerangkan bahagian lukisan yang sukar

dilihat dan difahami

d. Kotak tandatangan hendaklah disediakan.

Lukisan keratan pemasangan biasanya digunakan untuk menunjukan bahagian-bahagian

komponen yang diipasang bersama-sama. Semasa melukiskan lukisan keratan pemasagan,

peraturan-peraturan umum keratan hendaklah dipatuhi. Misalnya lukisan keratan tidak perlu

dilukiskan jika terdapat bolt, nat dan sebagainya.

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Lukisan pemasangan 2-dimensi

Lukisan Terperinci

Lukisan terperinci menunjukkan semua maklumat yang perlu dikenal pasti dari sesuatu

projek/produk. Lukisan terperinci mesti menunjukkan penerangan lengkap serta tepat,

gambaran projek termasuk bentuk, saiz, kelegaan, ‘surface finish’ dan rawatan haba yang

diperlukan.Ciri-ciri lukisan terperinci adalah seperti berikut:

a. Had terima hendaklah disertakan dalam setiap dimensi. Rujukan boleh dibuat kepada

standard BS 4500 atau ISO 286-2: 1988 untuk menentukan had terima.

b. Bahan dan proses pembuatan hendaklah dinyatakan dengan jelas.

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c. Format lukisan mesti mematuhi standard seperti yang dinyatakan dalam BS 308

Engineering Drawing Practice atau standard yang setaraf dengannya (Standard

Amerika Syarikat ANSI Y14.5M, Dimensioning and Tolerancing)

d. Lukisan terperinci merupakan alat komunikasi yang digunakan untuk menghasilkan

produk. Setiap lukisan hendaklah diluluskan.

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Drawing properties

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Title block

Drawing Views

The first view in a drawing must be a base view. Other views such as projection and isometric

views can be created based on the based view.

• Use the orientation list to select the orientation of the view based on the model’s origin

planes.

• Use the view/scale label are to set the scal of the view

• Use the style icons to set the line display of the view (hidden line, no hidden line or

shaded)

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A projected view is a view created by projecting from a parent view. The parent view must

already exist. You can create eight possible views from one view. Four orthographic and four

isometric

• The orthographic views are top, bottom and side views. These views align with the

parent view and are dependent on that view

• The isometric views are diagonal views. This views are not dependent on the location

of the parent view.

Projected view

Auxiliary views are similar to orthographic views except they are created diagonally from the

view based on a user-defined edge.

Auxiliary view

Section view displays the component with a cutaway. A projection view line/section line is

drawn on the parent view to locate the cut.

Section view

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Detailed view typically enlarge an area of a parent view to display the information more

clearly

Dimensions

Detailed view

Baseline dimensions enables you to create dimensions that share a common extension line.

Ordinate dimensions enables you ro create individual ordinate reference dimensions.

Chain dimensions enables you to create dimensions that are chained to one another.

Baseline dimension Ordinate dimension Chain dimension

Center marks

Center line

Center line bisector

Centered pattern

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Parts List

A part list is a list of all of the components in an assembly. An assembly drawing and parts list

can show how the parts of the assembly fit together and identify parts by numbers. Callout

balloons are used to number the parts. A numbered parts list contains corresponding item

numbers that identify the particular parts. You can place balloons either individually on parts

or globally on all parts in a view.

Bill of Materials

A virtual component is created to represent a non-geometrical part that is required in the bill

of materials (e.g. paint, air, grease, etc) Virtual components can also be used to represent parts

that you do not want to model such as fasteners.

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Normal

Phantom

Reference

Purchased

Default status for a component. Normal components are placed in the BOM

based on their parent assembly. They are included in the quantity

calculations and have no direct influence on their children’s inclusion in the

BOM

A phantom component is used to simplify the design. Although they exist in

the model, they are not included in the BOM and are not included in the

quantity calculations. Children of phantom components are listed in the

BOM at the same level as their phantom parent. Phantom components are

often used to ease placement of components.

Ex:

• Sets of hardware where the components are purchased and

assembled separately, but are commonly used together (for instance

screws, nuts, and washers).

• Installation Assemblies. For instance, when you want to focus on a

certain section of an assembly, you can set other subassemblies as

Phantom. Use Phantom to avoid working with a large assembly file.

Reference component is used in the construction of the assembly but is not

part of the actual design.Neither the reference component nor its children

are included in the mass, volume, BOM or quantity calculations. If a

subassembly is referenced, the entire subassembly’s physical properties are

excluded. If a single component in the subassembly is referenced, it is the

only one that is excluded.

Ex:

• Construction elements such as a skeleton part or assembly for

skeleton modeling.

Purchased components are purchased instead of fabricated. In the parts only

view, components with the purchased status are listed as a single item, even

if they are an assembly. Children of an assembly with purchased status are

not displayed in the parts only view and are excluded in quantity

calculations.

Ex:

• Cylinders, pistons, or shock absorbers.

• Swing arms for LCD monitors.

• Hinges.

Inseparable Inseparable components are assemblies that must be physically damaged to

be taken apart. Inseparable components behave in the BOM like purchased

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components. However, if a child of an inseparable assembly stauts is set to

purchased , it is listed in the parts only BOM

Ex.

• Weldments including assemblies that are glued or bonded.

• Riveted components fastened together with semi-permanent

fasteners that must be destroyed to separate the components.

• Assemblies where components have been press fit together, such as

dowel pins pressed into a part.

The material for each item can be modified from in the BOM Editor by adding the Material

column, selecting the Material cell for a specific item, and expanding the Material drop-down

list.

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