what are the 7 drawing conventions for
a) line styles
f)types of views
to assist in the reading and understanding of drawings.
why are different line conventions used on a drawing?
to give the drawing clarity
why are borders included on a drawing and which type of line is used?
to show that all intended information is shown on the drawing and they are the heaviest continuous lines
what are the lines used to transfer the edges of a surface from one view to another?
construction lines... they are very thin and faint
what are object lines used to show and how do they look?
used to show the edges of an object that are not hidden, they are heavy continuous lines that must stand out clearly.
what type of line is used to show hidden and/or internal surfaces?
lightweight dashed lines
thin broken lines consisting of a long dash, space, short dash, space and a long dash repeating are used to indicate what?
what dimensioning style is used on an architectural drawing?
aligned dimensioning with measurements above the dimension lines
what must be done to read vertical dimensioning when aligned dimensioning is used?
the drawing is to be rotated clockwise
what are the 4 parts of a dimension?
why is a space left between the object line and an extension line?
so that the extension line doesn't get confused as part of the drawing
how are dimensions shown when there is insufficient room to show the dimensions in a confined space?
placed outside extension lines with its end marks centered beside one of the dimension lines...above the space with a leader line or between the extension lines
what are leader lines and what are they used for?
used to point at an item that is described or identified by text. they are thin dark lines that run at an angle with an end mark on one end pointing at an item.
how should text be positioned to make a drawing easier to read?
ensure that it is not crowded and that the object + dimension lines don't run through it.
is every dimension shown in each view?
no, show dimensions only once don't show in every view
are hidden (invisible) lines dimensioned?
where and how should dimensions be positioned?
they should be kept to the outside as much as possible with shortest dimension closest to the object and overall farthest away.
what is the recommended offset of dimensions from the object?
the first should be offset by 10-12 mm with each additional by 6mm
what is the recommended margin from the borders to the edges of the paper?
10-15mm from the top, bottom and right edges with the left 2 to 2 1/2 times as large as the right
list 4 scales used when drawing a project shop drawing.
what is the name of the view that allows us to see the interior construction and assembly of an object?
list the 4 different types of sections?
1) cross section
2) partial sections
what are 2 types of cross sections?
what is used to identify the location that an object is assumed to be cut?
a cutting plane line
describe a cutting plane line.
it consists of heavy phantom style lines (long, short, short) also has section plane lines with a letter to show how its viewed
what type of views are most sections?
why are viewing direction arrows used?
to orient the section to prevent confusion.
how is the material to be used identified on a project shop drawing?
by using material symbols on the end of a piece section
what are details?
details are large scale drawings showing the construction of small targeted areas.
machine drawings use the unidirectional system. how can the dimensioning be read?
all the dimensioning values can be read from the bottom of the page
where are the dimension numbers placed on a machine drawing?
the numbers are placed centered on the dimension line
when are arrowheads usaully used on a dimension line?
for imperial drawings
when are oblique slashes usually used on a dimension line?
when are dots usually used on a dimensioning line?
for suppliers shop drawings
what size is dimisnsion text usually?
when using metric dimensions always use a space rather than a comma when the numbers are greater than?
10 meters 10 000mm
when using alternate units on a dimension line what measurement is shown first?
the primary unit of measurement is shown first
never use the centre line of a circle as a?
cicrcle and arc centres are marked to locate their?
3mm height of text is for?
6mm text is used for?
why do you want to keep notes horizontal?
for clarity and ease of reading
what are break lines?
they are the same weight and darkness as extension lines, can be used to show that an object is broken to show the details behind it. removed sections use break lines to show that a portion of the item has been removed