Namaskar friends, welcome to session 10 in
our course on Operations Management and today we are going to finish the discussion for
week 2 in which our focus is on product design and development. So, session 1 or in the first session of this
particular week we have seen what is a product life cycle. Then we have seen the concepts of value engineering
finally, we have seen design for x where we have seen two examples of design for manufacturing
and design for assembly. In the last session we have seen that how
we can design a product by keeping in mind the concept of ergonomics. So, basically we have learnt we have discussed
4 important tools which are very important in decision making in context of product design
and development. We have seen the product life cycle which
helps us in decision making, we have seen design for X that is design for manufacturing
design for assembly, design for manufacturing and assembly that also helps us to design
our product. We have seen the concept of value engineering
which also helps us in decision making related to the functions of the product, related to
the functional analysis of the product, related to the functional cost evaluation of the product
and the last session we have seen ergonomics which also helps us to take judicious decisions
in context or in reference to the interaction between the customer and the product, the
man and the machine or the interaction between the man and the system as a whole. So, basically we are not learning the different
steps involved in product design process, but we are learning the various tools and
techniques which can help us to design a successful product which will help like to improve the
economic health of the organization. So, in that series our focus today would be
to discuss the rapid prototyping concept that time is also very important. We have seen the product should be good, it
should be functional, it should satisfy the functions for which the product is being bought
by the customer, it should be easy to use it, should be comfortable to use, it should
be ergonomically design, it must be cost effective it must be efficient. So, there we can use n number of objectives
to define a successful product, but the time is also very important. I may have an idea today; I wish that I should
make a product out of this idea which is a tangible product which is a commercial product
which can be sold in the market. So, an idea has to be converted from an ideation
phase into the actual manufacturing phase and that time is very important the gap or
the time gap once you have an idea and that launch of the product in the market the time
gap between this these stages has to be minimized. And as a mechanical engineer usually we feel
that the prototyping takes away a lot of time, usually the designs today are made using software
using CAD. So, we know an auto CAD we have an idea we
can directly make that design on our screen we can have 2-D representation of the design,
we can have 3-D representation of the design we can look that design from different views. Once that design is ready we want to check
the functionality of the product and for that we need to make a prototype and that prototyping
will take a lot of time. Then if you see the conventional manufacturing
processes there are a number of courses being offered under MOOCs, on fundamentals of manufacturing
processes. So, once you see or understand these processes
like casting, welding, forming their other joining techniques like adhesive joining,
mechanical fastening. So, number of processes are there which can
be used to make a prototype, but all these processes have a time you can second straight
or time domain in which they can convert or a raw material into the final product. So, it is always difficult it is not impossible,
it is difficult to make the prototype in a very short duration of time or in the shortest
possible time, but that is our target. Today I have an idea any other person may
be in any other part of the word may also have the similar idea. Now, the person who is able to the engineer
who is able to convert that idea into the tangible product or a commercial product will
be the first person to gain advantage and all these study or all these topics that we
cover are interrelated. If you remember in product life cycle, we
have seen that during the growth stage the profits are maximum. So, if the product which has been designed
by our competitor or any other person in the other part of the world before we can converge
to a product before we could launch the product some other company or an individual has launched
that product. That person or that company will definitely
gain more advantage will be profitable as compared to our company why because we are
late we are delayed in the launch of our product because we have taken a lot of time in prototyping
the product. Therefore, we need to focus on the prototyping
technology that how quickly we can convert our idea into the final product or into the
prototype. The prototype can be just it can be a non
functional type of prototype we are just looking at it that how the product would look like
or it can be a fully functional type of prototype in which suppose 3 parts are made and then
we have to check that whether they will assemble properly or not or how they will look after
assembly. So, it can be a function, we can even check
the functionality of the product of the material for which the product is going to be made
up of is similar to the material that we have used for making the prototype. So, we can make both functional and non functional
type of prototypes. But the major focus is quick methods of making
the prototype and on your screen you see rapid prototyping. Now, rapid prototyping means that we have
to quickly convert our idea convert our design into the prototype. So, rapid all of you know means quick and
prototyping means we have to make or fabricate or process a prototype. There are a number of tools and techniques
or methodologies which have been invented and commercialized by researchers and scientists
number of machines are available based on the different technologies. There may be around 50 to 60 different technologies
that fall under the broad umbrella of rapid prototyping. We will not be covering any of these technologies
in today’s class. Our focus primarily is to focus on this concept
that what is rapid prototyping actually and how we can get benefitted by adopting the
concept of rapid prototyping. So, we will just be focusing on the concept
and we will be focusing on the advantages that we can derive out of these principles
of rapid prototyping. Otherwise there are machines available like
stereo lithography apparatus SLA, laminated object manufacturing, 3-D printing which is
very common these days, selective laser sintering. So, there are a number of technologies that
are available which can be used for converting the raw material directly into the product
in the minimum possible time. And all these technologies may use the raw
material which may be in terms of a liquid polymer, it can be particle, it can be sheets
of material. So, depending upon the type of raw material
that is being used for converting into the prototype these processes can also be classified
that these processes use liquid type of raw material, these processes use solid raw material
in the form of particles or there can be a group of processes which makes use of layered
sheets for making the prototype layer by layer by layer, consolidating these layers, layer
by layer. So, depending upon the type of raw material
used we can very easily classify these rapid prototyping technologies. So, I have named a few of them and in our
course on product design and development which was a 10-hour course which was offered under
MOOCs and I think the videos are now available on YouTube. You can refer to these technologies also and
try to understand the basic concepts we have tried to explain them with the help of images
with the help of schematics and you will be able to understand that how a particular tech
rapid prototyping technology actually operates and converts a raw material into the final
product into the minimum possible time. But today our focus would primarily be to
understand; what is a rapid prototyping I think by the discussion we had today maybe
5 to 7 minutes have already passed. Many of you might have got an idea about rapid
prototyping and in the structured lecture that we have today we will further try to
cement this concept of rapid prototyping and we will see that what are the various stages
involved. Because in different technologies as I have
already told you the major steps involved are more or less same the raw material may
be different, the process of consolidation may be different, but the basic steps involved
in the overall rapid prototyping process are same. We will try to understand what are the steps
involved and finally, we will see; what are the advantages that we can derive out of rapid
prototyping. So, let us quickly start our presentation
and try to understand the concept and advantages of rapid prototyping process. On your screen you have the meaning of prototype,
prototype basically originated from the Greek word in 1603 prototypon a first or primitive
a first or primitive form. So, prototypon own is a Greek word from there
it is a first or the primitive form. So, if for any product you say; what is the
prototype of this product it can be the model of that product or the first form of that
product. So, protos means first form and typos means
form. So, proto plus typos means first form of the
product. So, protos means first and typos means form. So, prototype means the first form of the
product. It is an art of managing the expectation. So, it is art of managing means that we have
to see, we have imagined a product, we have designed a product on our computer screen
using any CAD or designing software. So, once we have designed the product we have
imagined the product. So, here what we are doing we are managing
that expectation we are producing that expectation in the form of a tangible or a physical product. So, it is an art of managing the expectation. An original, it will be an original means
a new product full scale. So, it can be made up to the scale or we can
make a scaled up or scaled down model also, but usually we try to make a full scale model
or a full scale prototype and usually working model of a new product or a new version of
the existing product. So, we can make a working prototype of a product. So, as I have told you I have used the word
functions because we have already discussed the functional analysis or the value engineering. So, it can be a functional product. For example, suppose we are making outer covering
of a mosquito repellent all of us use mosquito repellent devices. So, we are making an outer covering of a mosquito
repellent device and it is a completely new design which has different aesthetics involved. So, what we can do we can directly make a
CAD file of that particular design and convert it using any machine into a product. So, it is a functional product now what do
we can do we can use it as a product also and see how it performs. So, usually in rapid prototyping we try to
make the functional or the working products only are the working models of the designed
product. Many times we may just make product just to
see as how aesthetically it will look. So, those may not be the working products,
but in many cases our focus would be to make the working products only or the working prototypes
similar to the product that we want to design. Now, this is the history of rapid prototyping. So, in 1770 the concept of mechanization came
into being I will not read I each and every step involved here, but in 1988 the first
commercial rapid prototyping mechanism or technology was developed. Now, rapid prototyping technologies are able
to produce physical model which I have already explained in a layer by layer manner directly
from their CAD models. Now, you can see that; what is the output
the output is a physical model of the product. How it is made? It is made layer by layer manner. From where do we get the information? From the CAD models; without any tools dies
and fixtures and also with little human intervention, so these processes can be fully automatic,
human intervention is minimum. So, we can say that if we have a CAD file
or we can say design file of a product in the form of we can say in a memory stick or
we can interface directly the computer where we have designed the product with a rapid
prototyping machine. So, the input required is the soft copy or
the design in the form of a CAD file. So, that is the pre primary requirement we
need to have a CAD file of the design. In many cases when we do not want to develop
the CAD file of the design we have already have a product available with us. We do not have the CAD file of the product,
but we have a product a physical product available with us which is slightly damaged. We want to reconstruct that product what we
will do there are scanners available in the market. These scanners will construct a three dimensional
file for that product just by scanning the product and once we have that file in our
system we can use that file from our computer as an input file to a rapid prototyping machine
and it can be converted into the physical product using the file that we have created
by using the scanner. So, there are lot of we can say opportunities
available with the rapid prototyping technology. So, without use of tools and dies and fixtures
we are able to produce a rapid prototype in a very time effective manner. So, RP is capable of fabricating parts quickly. So, as the word rapid, they are able to generate
quickly, with complex shape easily as compared to the traditional manufacturing processes. Two advantages are coming here; one is quick
another one is complex. So, one thing is that we are able to produce
our prototypes quickly I have highlighted that maybe number of times today and the second
point which I have not highlighted is that if the product is also very complex still
we are able to make a prototype quickly as compared to the traditional manufacturing
technologies. Simple example I would like to take here,
that suppose there is a complex product and in earlier days you would like to make a prototype
using a casting process how we will make a prototype, it has to be a metallic prototype. So, if it is very complex it is difficult
to machine. So, we have decided let us do the casting,
but for making the casting operation or for performing the casting operation we still
require a pattern because that will help us to make a mould. So, for making a pattern again we require
maybe another technology that how to make a pattern suppose you use a wooden pattern
we need to cut the wood into that complex shape. So, traditional manufacturing route of making
a pattern making a mould and then making a casting and then finishing the casting may
be a longer route of making a prototype. Whereas, in case of rapid prototyping what
do we require? We require only a CAD model of that product
and if that model is available to us we can very easily fabricate it using any of the
rapid prototyping technologies. So, complex parts are also made easily by
the rapid prototyping process as compared to the traditional manufacturing technologies. RP helps in earlier detection and deduction
of design errors. Now, you see if we have designed a product
and we have used the conventional route of making a prototype and after making the prototype
we do the testing and inspection and find out that these are the design errors again
we have to revert back to the design stage. But here since the time required for making
the prototype is shortened it is less, so quickly we will be able to identify that these
are the errors that are happening. So, we will just revert back and modify and
then again come back and make the prototype. Now, this since the input here also is a CAD
model it is very easy to make the changes. So, it is easy for design modification concept
point of view or design modification point of view again the rapid prototyping technology
is much better as you can where as compared to the conventional method of design as well
as to prototyping or manufacturing of a prototype. So, we can see that there are a number of
advantages if we adopt the concept of rapid prototyping. Now, all RP techniques employ the 5 step process. So, basically there are 5 steps or 5 stages
in which we can make a prototype. So, first of all what we have to do? We have to create a CAD model of the design. So, CAD is computer aided design. So, we have to use any software and make a
3-D model of the design. In second stage convert the CAD model to STL
format. So, we have to because these machines understand
a specific language only therefore, whatever CAD software we have used to design the product
we have to convert it into a language which the machine can understand. So, we have to convert that model to the STL
format. Now, we have to slice that STL file into thin
cross sectional layers. Now, suppose I can take an example of this
pointer I want to make a prototype of this pointer, I have to first make a CAD file which
is as per the dimensions this is the length, this is the width, this is the thickness,
thickness is varying across the length. So, we will see up to this particular length
this is the thickness and after that this is the thickness. So, we will make exact dimensions a CAD file
three dimensional file of this particular product. Now, once we have to make a prototype because
we have seen that most of the rapid prototyping processes produce the prototype layer by layer,
we have to see that in how many layers this product would be made because you see here
the thickness is more and here the thickness is less. So, we have to slice this product into number
of layers and that number of layers will be deposited one after the other and this 3 dimensional
physical product or the prototype will be created. So, the third stage is the decision regarding
the number of layers. Now, we can use more number of layers, thickness
will be less. We will go for less number of layers, thickness
of individual layer will be more. Now, depending upon the technology that we
are adopting we have to do the slicing of the product into number of layers. So, that is done in the third stage. What we have done till now, we have used any
CAD software to make a model a CAD model. Now, this CAD model has been converted into
the STL file and this STL file has now been sliced into individual layers. Now, construct the model one layer a top another
once this product this is we can say the planning process the first three stages and now we
are going into the execution of the program. So, first we have a CAD model which is all
now available we have converted into a STL file we have sliced the STL file input number
of layers and now this is the input to a rapid prototyping machine and once this input is
given to the rapid prototyping machine it starts to produce or fabricate or manufacture
the product layer by layer or manufacture the prototype layer by layer. So, first layer will be deposited as per that
design, then the second layer will be deposited on top of the first layer, then a third layer
on top of the second layer, then fourth layer on top of the third layer. So, layer by layer the material will be deposited
and the physical three dimensional prototype would be produced. Then the last is clean and finish once this
layer by layer you have created your prototype you have manufactured your prototype, you
have produced your prototype, we will take it out and because it has been done layer
by layer by layer it will require a finishing operation in order to have a smooth surface
that is the we can say requirement of the design. So, last stage is cleaning and finishing of
the model. In case of a very very complex shape sometimes
we use supports also during the fabrication and during the last stage we have to remove
these support systems in order to get the product or the prototype only. So, this supporting system which has been
used to create the prototype will be of a different material may be for example, vex
and later on we can heat our prototype slightly. So, that wax can melt and go away and we get
our final prototype. So, sometimes supporting structures are also
used during the fabrication of the prototype. But still compared to the traditional method
compared to the conventional method of making the prototype rapid prototyping technologies
are much superior in terms of quality produced, much superior in terms of type required maybe
less time is required for making a prototype using the rapid prototyping technologies. So, these are the 5 steps that are followed. Now, quickly let us see the rapid prototyping
system. The source is given here iitd.ac.in. So, this is we can say there is a CAD model
of the part, then converting to STL format converts slicing, converting into layer then
there is a rapid prototyping machine through which we are creating the prototype and finally,
in post processing or finishing of the part. So, here you can see CAD model converts conversion
to its STL format layer by layer slicing of the model and then finally, the creation of
the model here, generation of the physical model and finally, in here the creation may
be the generation of laser scanning paths or material deposition paths. So, we know now for making the product this
is a path in which the material or this is the area in which the material has to be deposited,
how our head will move in order to deposit the material at the respective places that
decision is also taken. And finally, if you if you can read on your
screen this is the box type of arrangement here is a rapid prototyping system it can
be any machine it can be a 3-D printing machine, it can be a stereo lithography upright as
it can be a selective laser sintering setup it can be a laminated object manufacturing
machine this is the RP system. So, before entering into the RP system or
before using the RP system we have to do all these calculations, we have to see we need
we do we have a CAD model, have we done that we, have we converted it into the STL format,
have we sliced the model properly decided on the number of layers have we generated
the path to be followed by the head. Once all this input is ready we give this
input to the rapid prototyping machine and then it will create a prototype and finally,
we will do the post processing and finishing of the part. Now, CAD model creation first the object to
be built is modelled using computer aided design I have highlighted already. Solid modular such as Pro/ENGINEER tend to
represent 3-D objects more accurately then wireframe modular such as auto CAD and will
therefore, yield better results. Now, that is from the CAD point of view that
once you are making a CAD model of your product you need to make a judicious decision that
which software is going to help us to make your model better. This process is identical for all the rapid
prototyping techniques. The steps that we have followed are more or
less identical for all rapid prototyping technologies. Conversion to STL format, but maybe the previous
was that the CAD model is required for almost all rapid prototyping technologies. Conversion to a STL format the second step
therefore, is to convert a CAD file into that STL format this format represents a three
dimensional surface as an assembly of planar triangles. So, we have to convert it into this format
that CAD file into STL format. STL files use planar elements, they cannot
represent curved surfaces exactly. Increasing the number of triangles improves
the approximation. So, we have to convert our CAD file into the
STL format which will represent the planar surface in the form of small triangles. Slice the STL file, in the third step pre
processing program prepares the STL file to be built. In a pre processing software slices the STL
model to number of layers you know what can be the thickness of layer it can be 0.01 millimeter
to 0.7 millimeter thick depending upon the rapid prototyping technique that you are going
to use. So, you can see are lot of range is there
that what can be the number of layers, that we are slicing, that will be used for fabricating
the part or the fabricating the prototype. The program may also generate an auxiliary
structure as I have told earlier a support structure to support the model during the
build, you know during the building process or during the fabrication process. Supports are useful for delicate features
such as overhangs, internal cavities and thin walled sections. So, once your product your prototype is being
fabricated there may be certain sections which may require some additional support during
fabrication and this support is provided by the auxiliary material which I have told you
earlier can be wax which later on can be removed and then you get your actual prototype. So, this is the third stage. And then we do layer by layer construction,
the fourth step is the actual construction actual fabrication of the product or the prototype. RP machines build one layer at a time from
polymers papers or powdered material I have already highlighted in the beginning of today’s
session. Most machines are fairly autonomous needing
little human intervention. So, these are more or less automatic machines
which help us to create our prototypes. Clean and finish, the final step is post processing
this involves removing the prototype from the machine and detaching any supporting structures. Some photosensitive materials need to be fully
cured before they are used. So, we have to use additional maybe heating
mechanism or additional furnaces to fully cure these resins before making them fully
functional prototypes. Prototypes may also require minor cleaning
and surface treatment. Sending ceiling under painting the model will
improve its appearance and durability. Now, what can be the advantages? I think I can ask this question to all of
you I have tried to explain it in the most simplistic manner. Everybody must be able to answer now that
what are the advantages of rapid prototyping. Simply it is process is fast and accurate,
superior quality surface finish is obtained, separate material can be used for component
and support, no need to design jigs and fixtures because we are not using the conventional
methods of producing or fabricating the prototype. We are using a completely advanced technology
for creating a prototype and therefore, there is no need of jigs and fixtures and no need
of a mould or other tools. Only requirement is the CAD file of the product. Once we have the CAD file we can convert it
to STL file from there we can slice it, we can create the tool path and finally, use
any rapid prototyping technology to convert that product into its prototype. So, with this we come to the end of today
is session on prototyping concept and advantages. In our next week we will start a discussion
on a completely new topic, but just to summarize what we have covered. Till today we have finished two weeks of discussion:
week 1, was on fundamentals of operations management we have seen their objectives,
scopes, functions as well as operation strategy. In second week we are focused on that once
you are managing the operations you must know that what the company must produce in order
to be successful. And there we have seen different tools techniques
which can help a designer to develop or design a product which is much more you can say competitive
and successful in the market. We have seen, we have seen product lifecycle,
we have seen value engineering, we have seen design for x, we have seen ergonomically,
we have seen rapid prototyping. So, all these tools are helpful for designers
for designing a successful product. With this we close today’s session. Thank you.
