TOPICS
Preparation of Tools.
Using of Tools
Applied Geometry
Preparation of
Tools
Fastening Paper to Drafting Board
- Place the paper close to the table’s left edge.
- Move the paper until its lower edge place about the top edge of T-square.
Fastening Paper to Drafting Board
- Align the top edge of the paper with T-square blade.
- Attach the paper’s corners with tape.
Fastening Paper to Drafting Board
- Move T-square down to smooth the paper.
- Attach the remaining paper’s corners with tape.
Preparing the Compass
- Sharpen the lead of Compass with a sandpaper .
- Adjust the needle and the lead so that the tip of the needle extends slightly more than the lead.
-
Tools
T-square
Compass
Circle template
Straight line
Arc, Circle
Using the Compass
- Locate the center of the circle by two intersecting lines.
- Adjust the distance between needle and lead to a distance
equal to radius of the circle.
- Set the needle point at center.
Using the Compass
- Start circle. Apply enough pressure to the needle, holding compass handle between thumb and index fingers
- Complete circle. Revolve handle clockwise.
Using a Circle Template
- Draw two perpendicular lines that pass through center of a circle to be drawn.
- Place the template till all marking coincide with center lines.
- Tracing the circle. (Hold the pencil normal to the paper.)
Given
Object line Construction line
Draw a Horizontal Line
-
Press the T-square head against the left edge of the table.
-
Smooth the blade to the right.
Draw a Horizontal Line
- Lean the pencil at an angle about 60o with the paper in the direction of the line and slightly “toed in”.
- Draw the line from left to right while rotating the pencil slowly.
Draw a Vertical Line
- Set T-square as before. Place any triangle on T-square edge.
-
Slide your left hand to hold both T-square and triangle in
position.
Draw a Vertical Line
- Lean the pencil to the triangle.
-
Draw the line upward while rotating the pencil slowly.
Draw a line at 45o with horizontal
-
Place 45o triangle on the T-square edge and press them firmly against the paper.
- Draw the line in the direction as shown below.
-
Draw a line at angle 30o and 60o
-
Place 30o-60o triangle on the T-square edge and press
them firmly against the paper.
- Draw the line in the direction as shown below.
Draw the line passing through two given points
- Place the pencil tip at one of the points.
- Place the triangle against the pencil tip.
- Swing the triangle around the pencil tip
until its edge align with the second point.
Applied
Geometry
To Bisect a Line
the line with the centers at the ends of the line.
Join the intersection points of the arcs with a line.
Locate the midpoint.
To Bisect an Angle
- Swing an arc of any radius whose centers at the vertex.
- Swing the arcs of any radius from the intersection points between the previous arc and the lines.
- Draw the line.
To draw the line parallel to a given line and passes through a given point
Given distance = r
Adjacent-sides method
Using Compass
To draw the line perpendicular to a given line at a given point
Using Compass
To draw a line making 15o with a given line and pass through a given point.
Given
To draw a line making 15o with a given line and pass through a given point.
Given
To draw a line making 30o with a given line and pass through a given point.
Given
+
To draw a line making 75o with a given line and pass through a given point.
Given
FILLET AND ROUND
FILLET AND ROUND
To draw the arc, we must find the location of the center of that arc.
How do we find the center of the arc?
To draw an arc of given radius tangent to two perpendicular lines
Given arc radius r
To draw an arc of given radius tangent to two perpendicular lines
Given arc radius r
center of the arc
Starting point
Ending point
To draw an arc of given radius tangent to two lines
Given arc radius r
To draw an arc of given radius tangent to two lines
Given arc radius r
To draw a line tangent to a circle at a point on the circle
Given
To draw a line tangent to a circle from a point outside the circle
Given
mark a tangent point
When circle tangent to other circle
The center of two circles and tangent point lie on the same straight line !!!
To draw a circle tangent to two circles I
Given
Example
To draw a circle tangent to two circles I
Given
Two circles and the radius of the third circle = R
To draw a circle tangent to two circles I
Given
Two circles and the radius of the third circle = R
Repeat
When circle tangent to other circle
The center of two circles and tangent point must lie on the same straight line !!!
To draw a circle tangent to two circles II
Example
Given Two circles and the radius of the third circle = R
To draw a circle tangent to two circles II
Given Two circles and the radius of the third circle = R
To draw a circle tangent to two circles III
Given
Two circles and the radius of the third circle = R
How to Keep Your Drawing Clean
Do Don’t
