The UK’s national standard for engineering drawings is BS 8888. This defines the requirements
for a drawing of a products and their component parts. This standard is unique
to the United Kingdom but some other countries use similar national standards.
The BS 8888 covers many different aspects within the UK and national drawings.
It gives Technical Product Specification like:
Allows drawings to be done in 2D or 3D
Gives letter and number requirements
It gives information on Tolerances:
Linear tolerances, which includes limits and
General tolerances, which includes BS EN 22768
Surface textures and finishes
It gives Geometrical Product Specification:
The 4 geometrical properties
The 7 step system
It gives features and features of the size. It also gives
size tolerances and things like the Envelope Requirement and ISO 14405-1. Also
it shows many different markings on drawings and allows for compliance to the
standard and also allows for the implementation of the standards within the
ISO 128 is an
international standard which shows the general principles of presentation
within technical drawings but mainly the graphical representation of objects on
ISO 1101 is an
international standard that focuses on geometrical tolerances. Tolerances of
form, orientation, location and run-out.
P.2 – Explain which
features of CAD drawings need to comply with national and International
CAD standards are a set of guidelines that all CAD drawings
should follow to improve the productivity and so the drawings can be copied
into other CAD programs. There are a few features within a CAD drawing that
should all comply with the national and/or international standards:
Text and Dimension
File naming standards
These should always comply with the correct standards
because they all need to be done to the same standards so that they can all be
read correctly and so everyone can understand the drawing. The standard it is
drawn in should be written in the title block of every drawing so that they can
be easily understood and the person using the drawing know which standard to
read it in.
P.3 – Explain the
advantages, compared to other methods, of producing drawings electronically
using a CAD package.
There are many advantages of using a CAD package when
producing electronic drawings. First of all though, CAD is very important and
has made the storage and retrieval of products and drawings a lot easier as
they are all stored electronically. However, manual drawing is still very
important as it provides the basics of how to draw certain types of drawings.
There are many advantages of CAD, one is that there is no need for scaling the
drawing as all the drawings are done to the correct size. Also the screen
drawing area can be changed size very easily so you can create any size
drawing. Also when drawing CAD drawings, all the tools are supplied by the
program. And also using CAD means you will be extremely accurate at all times.
Production detail can be extracted straight from the drawing
which save a lot of time and they are also very accurate. Another advantage of
using CAD over manual drawings is that both 2 and 3 dimensional drawings can be
produced very easily. There is a very low chance of losing your drawing as it
saved on your computer and can also be saved in other places like a USB stick.
Which also means that all the drawings are stored on the computer on a USB
drive so there is no need for a big folder because it’s all stored
Dimensioning can be almost automatic on CAD drawings so you
won’t have to measure things individually and writing it in. Also parts of
drawings can be saved and copied into other drawings when needed so it saves
time and also makes making a product with multiple parts very simple.
P.4 – Describe the
software and hardware that are required to produce CAD drawings.
There are many types of CAD software that you could use. It
is important when choosing the piece of software that you use that it does
everything that you would like it to do. For example if you are looking to
create a wiring drawing then you wouldn’t use Autodesk Inventor as that makes
3D and 2D parts. Also a less popular CAD software will have a smaller array of
tools and users may be restricted to certain graphics cards etc. An obvious thing
to do was to make sure that your computer or device you are using actually
supports the CAD program you intend to use. If not you may need to update your
hardware or get a supported piece of software.
Like I previously said it is important to check the
specifications of your hardware to see whether it is capable of running the CAD
software you have chosen. If not then you could also find out whether there is
a more powerful machine is required in order to run the program you wish to
use. Most CAD software’s are run on Windows PC’s and not Apple Macs or Linux
etc. Also the hardware should have enough RAM to run the software and a big
enough hard drive to hold the program and also any work that you will carry out
on the program. If you are making large drawings/models then it will require a
much more powerful computer. However if the drawing contains no 3D sections and
is completely 2D then the computer won’t need to be as powerful. If a CAD
software has a significant update then the specifications of the hardware may
need to be upgraded in order to run the new and improved program.
The monitor or screen should not be distorted and should be
as big as you can afford. This is because a bigger screen will make it easier
to see bigger images and also see the smaller details a lot easier. A plotter is used to print the drawing
properly. A good plotter will produce the drawing no matter the size to a
M.1 – Explain the
relationship between CAD and other software/hardware used in manufacturing.