drawings Flashcards
(10 cards)
what are the advantages and disadvantages of hand drawings
Drawing by hand takes a long time and mistakes might of happened. The work is done by such jobs as architects and engineers.
Hand drawings are cheap to produce:
Low cost equipment.
No new technology.
No yearly subscriptions.
state some reasons why computer drawings are preferred
Computer drawings can be of better quality and very accurate. The higher accuracy will lead to better designs and these better designs helps make manufacturing faster.
Computer drawings are easily saved and shared. The designs and drawings created by CAD can be easily saved and kept for future use and reference and they can be sent by email across the world.
These drawings are modified and reproduced more quickly. Modifying the CAD drawing is easy with all the tools available. They give the ability to create 3D CAD Models: CAD has the capability to transform an idea into a visible sketch in a matter of few minutes.
what are visible lines used for?
This is a thick dark line that is used to show the outline of an objects visible edge or surface.
what is a hidden line used for?
This line is made up of short dashes. It is used to represent the lines or a feature that are not visible from the direction of view in a drawing. These lines can be used to show the back of a product.
The hidden line should begin with a dash in contact with the line from which it starts.
what are centre lines used for?
This is represented by a series of alternating dashes, both short and long.
This line is usually used to indicate the centre of circles, holes, fillets, or circular/curved edges in a drawing. It can also be used to indicate the centre line of symmetry.
A centre line should always extend beyond the edges of the drawing.
what are construction lines used for?
These lines are usually drawn first. They are very light and thin lines used to construct layout work on an engineering drawing sheet. This is to help make sure components are in line with each other.
The line weight is irrelevant because these lines do not appear on the final drawing. On a computer they can be deleted. However, if drawing by hand, these should be dark enough to see and light enough to be erased.
what is a title block
A title block on a drawing is usually located in the bottom right-hand corner and contains all the information necessary to identify the drawing. The title block is separated into different sections.
Title block has the highest concentration of information in a sheet of engineering drawing. It is key to understanding the drawing and includes all the information which enables the drawing to be interpreted, identified and manufactured.
state everything that should be found on a title block
Drawing reference number in drawing as per sequence along with reference to others
Signatures and approval stamps and dates to revisions
Author
Drawing number
Date
Title
Materials
Scale
Sheet number
System of measurement
Projection
state 3 reasons why title blocks are important
Scale. The scale enables you to work out the real size of the parts of your home that the drawings represent. The scale and size of the paper should both be indicated. If you get the same drawing on a smaller size of paper, the scale will be altered.
Date. The date of issue is important for legal reasons such as patent rights and traceability.
Sheet number. The sheet number shows how many individual sheets are required to describe a part completely. For many small parts, only one sheet is required. When parts are large or complicated, multiple sheets are required.
