# Draw scaled down drawings

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### Manual:

Scale Rulers: Scale Rules are used to draw scaled down drawings so it Is possible to fit a 300m tall building on a piece of A3 by using the scales on the ruler for example if you have a 10cm line on a scale drawing of 1:10 that 10cm line would actually be 100cm in real life. It is important to make sure that your ruler has no chips out of it and you have to make sure that it is clean because the little bits of dirt that raise the ruler of the table could mean that you don't manage to get the drawing as accurate as needed.

Pencils: There are many different kinds of, colours and thickness pencils but when it comes to Technical drawing they suggest that you always use a 2H or 4H because these give nice clear thin lines as long as the pencil is sharp, the reason we don't use anything less than a 4H is because the graphite is too soft and doesn't give clear enough lines for the attention to detail that is required.

Protractors: Protractors are used to measure angles these aren't used so much in a lot of technical drawing but there are occasions where one is required, these aren't always the most accurate of equipment but the get the job done when needed.

Compass: Compass's are used for drawing perfect circles they use the pin to stick into the drawing and then you rotate them from the top to allow the pencil to trail lightly along to make sure it doesn't get caught which could ruin the accuracy of the circle this is why we use CAD because the is no problem for a computer to make a perfect circle where as it can quite difficult using a compass perfectly.

Set Squares: Set squares are used for measuring and drawing angles the two main sizes they come in are 45 degree by 45 and this is the set square that looks like a "right angled" triangle then there is the 60 degree by 30 degrees but it is much easier just to get an adjustable set square which will be able to do more than just the main two. When using CAD there is a lot of tools that are available to make measuring angles a lot easier.

Erasers/Rubbers: Erasers are very rarely used in technical drawing because you are meant to be very accurate first time but everyone makes mistakes and this is why we use CAD because it is far more accurate and if you make a mistake you can just correct it without the being a mess, but when drawing we make sure that we do not press the pencil to hard when drawing because the line will not rub out easily and you will still be able to see the indent in the paper, which would ruin the quality of work.

Templates: Templates are used to quicken the process of drawing a certain object these will be made very accurately as to make sure that the person who uses them doesn't get an inaccurate shape, when using CAD there is a lot of ready templates to use which will be a lot more accurate than the man made templates.

Drawing Boards: Drawing boards are used for manual drawing because it allows you to be a lot more accurate because you clip your work in place and it cant move, good drawing boards will have a fixed horizontal ruler that can be moved to places needed this also helps keep the work accurate, it is important to keep the surface that you place the paper on is clean so that there will be no bumps that appear on the paper because of dirt that you have drawn over underneath, obviously using CAD eliminates the need for a drawing board which makes things easier.

Requirements For the Computer: A CPU which speed is at least 3 Giga-Hertz, an operating disk capacity of 2 Giga-Bytes Ram and at least 2GB free disk space on the hard drive, For presentation purposes a VDU with a resolution of 1280 x 1024 and a display adaptor capable of 32-bit colour and a graphics card of 128MB and also the computer should have the abilities to be networked this will be explained why later on. While this may cost a lot of money to actually get a computer of this quality the rewards will be high not only will you be able to draw quicker using the computer it will also be a lot easier and a lot higher quality work which will be much more accurate. It is very important to have a computer that has the correct requirements for the CAD software because for it to work correctly and accurately you need the correct requirements.

Intranet and Project Extranets: There are three typical kinds of hardware configurations for a CAD system in a design office and these are:

Standalone Single User: This is where the CAD software and drawing information is held within a private domain. Information is used by plotting off the drawings and sending them by post or sending electronic copies of the drawing files by email.

Small Office-based Intranets: These are set up using LAN (Local Area Network), this will mean all computers in the building that are set up to the same internet can transfer information from computer to computer very swiftly and no one can access the LAN unless there on the same internet, They may also have a system in operation that will prioritise one persons work over the others for example Architect A's may be more important to the set deadline that Architect B's.

Large Multi-location extranet: This is set up for a wide area network (WAN) this is where drawing information is uploaded to a public domain on the internet which is accessible to all the various members of the project team with users in different locations. This is only provided when you subscribe from the CAD software company.

### P2

Method 1:

There are two main kinds of CAD, the first is the simplest this is 2D which mimics the processes involved in creating hand-drafted drawings, and to some extent many design practices still use this for the majority of their work. This method uses similar conventions to manual drafting representing real 3D architectural elements through a series of flat 2D graphical images, typically consisting of plans, sections and elevations, this is to provide a more realistic 3D effect, traditional geometric techniques are created such as two-point perspectives and isometric views. While this technique will not cost you nearly as much money as the one to come it will be no where as accurate or as aesthetically pleasing when you have finished due to the quality of the hardware and software.

Method 2:

The second process for producing CAD drawing or plots utilises powerful hardware systems and complex software programs to produce a set of virtual architectural objects. These objects behave as complete architectural elements and not just a geometric pattern of lines or a wire framework as in the previous 2D method. These objects when combined form a virtual 3D model of the construction project such that they not only contain location and spatial information but also can hold information about the physical specifications of the objects know as a single model environment (SME). While method two is a lot more accurate and aesthetically pleasing the hardware required to run such software is incredibly expensive, but if you are a large company there wouldn't be to much problem. We would only use method 2 for a large company and for an important building plan as well if it was only a small extension onto your house you would use method 1.

### P3

When working in a large company using CAD it is important to be able to transfer information fast, safely and easily there are a few different techniques to this and it would all depend on the size of the business, for example if you only wanted to transfer information from one PC to another in a building you would use a LAN (Local Area Network) whereas if you were wanting to transfer to another building still with in the company you would use a WAN (Wide Area Network). Networking saves you a lot of problems when it comes to transferring data, previous to now we would have either actually of handed over a drawing or a model, or would have had to use a memory stick or disk.

This is a general overlook at the three types of transferring data:

Intranet and Project Extranets: There are three typical kinds of hardware configurations for a CAD system in a design office and these are:

Standalone Single User: This is where the CAD software and drawing information is held within a private domain. Information is used by plotting off the drawings and sending them by post or sending electronic copies of the drawing files by email.

Small Office-based Intranets: These are set up using LAN (Local Area Network), this will mean all computers in the building that are set up to the same internet can transfer information from computer to computer very swiftly and no one can access the LAN unless there on the same internet, They may also have a system in operation that will prioritise one persons work over the others for example Architect A's may be more important to the set deadline that Architect B's.

Large Multi-location extranet: This is set up for a wide area network (WAN) this is where drawing information is uploaded to a public domain on the internet which is accessible to all the various members of the project team with users in different locations. This is only provided when you subscribe from the CAD software company.

### M1

Advantages: CAD can be far more accurate when used properly this is due to the nature of the software, if you can use the CAD software properly it can also be a lot quicker when producing a technical drawing. There are certain things that would be very difficult to draw by hand but CAD software makes it a lot simpler. You don't require lots of different small bits of equipment like pens, pencil etc. instead all you need is the software and a computer with the correct requirements. They programmes with have built in templates which will be a lot more complicated than hand made templates which will allow you work a lot quicker. If you make a mistake it is very easy to erase what mistake has been done without damaging the page as you would if you used an eraser on paper. Simple tasks like drawing straight lines are made a lot simpler by the fact that they are already perfectly straight all you have to do is place them where you need. The technical drawing that is produced by CAD is always more aesthetically pleasing than a manual drawing. The size of drawings and the area requires drawing them when doing manual drawings can be an annoyance, so that is another advantage the fact that you don't have to have any scales nor lots of space to draw in.

Disadvantages: There is the chance of human error still even though you are doing it all on a computer, this is because if the person using the programme is not competent in the software there is a chance they will not use it properly and thus will lose accuracy in the work, and also it is just as plausible for them to completely competent in the software and to just have a lack of concentration for a second and make a mistake also. Due to the fact that computers are powered by electricity they can easily lose power and have your work deleted due to this. Computers can occasionally crash causing you to lose work also.

### Manual:

Advantages: You don't require an expensive computer or software to be able to produce a technical drawing. The equipment you require is not too expensive if you are getting the lower end quality equipment. Learning how to do technical drawing manually is a lot simpler than learning how to use a piece of very complex software. You don't have to work for a large company that can afford CAD software to be able to do technical drawings.

Disadvantages: Human error can happen a lot more often than when using CAD as every last thing your doing you are doing by hand. The equipment that you are using can become damaged over time and use, which of course affects the quality and accuracy of the work. Manual drawing can be a slow process if you are doing a large accurate drawing. No matter how good your are at manual drawing if someone draws a technical drawing with CAD software correctly then it will always be more accurate than a hand drawn technical drawing. If you make a mistake using an eraser can affect the neatness and aesthetics of the technical drawing. While it isn't to say that a manual drawing can be aesthetically pleasing, if CAD drawings are done properly they will be more aesthetically pleasing. When doing a large drawing you have to scale it down, this obviously takes time and effort also if you are drawing on a large piece of paper you have got to make sure that you have a large enough area for it.

### D1

How the quality of graphical information effects the accuracy of technical drawings.

When were talking about technical drawings accuracy is the most important aspect of all, and due to this it is important to make sure that you have, well conditions equipment, this is vital because for example a pencil when doing scale drawings by hand you will always use 2H or 4H, the reason we use harder leaded pencils is because it gives much thinner finer lines, which allows for a lot more accurate work because, when doing scale drawings a 1mm thick line will be taken and multiplied by whatever scale your using so for example; with the scale of 1:100, 1mm would be 10cm in real life now this wouldn't make much of a problem but, if you were doing it scale 1:5000 and you used a 2B pencil you could end up drawing a line that is 5mm thick and could end up losing 5m all the way around the border of the site because of the thickness of the line on the technical drawing. Another important rule is that you cannot just trace a scaled drawing if the building you're making looks identical, you will have to start from the beginning making sure that every measurement is taken from the project that's in hand.

Bibliography: The only information that was not my own was taken from the BTEC Construction building services & Engineering & Civil Engineering by Heinemann.