2 Using Drawing Tools & Applied Geometry

 

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

1. Locate the center of the circle by two intersecting lines.
   
2. Adjust the distance between needle and lead to a distance
   

   equal to radius of the circle.
   

3. Set the needle point at center.
   

   

   

   

     
   

   Using the Compass
   

4. Start circle. Apply enough pressure to the needle, holding compass handle between thumb and index fingers
   

5. Complete circle. Revolve handle clockwise.
   

 

Using a Circle Template

1. Draw two perpendicular lines that pass through center of a circle to be drawn.
   
2. Place the template till all marking coincide with center lines.
   
3. Tracing the circle. (Hold the pencil normal to the paper.)
   

Given

Object line Construction line

Draw a Horizontal Line

1. Press the T-square head against the left edge of the table.
   
2. Smooth the blade to the right.
   

   

   
   

   Draw a Horizontal Line
   

3. Lean the pencil at an angle about 60o with the paper in the direction of the line and slightly “toed in”.
   
4. Draw the line from left to right while rotating the pencil slowly.
   

Draw a Vertical Line

1. Set T-square as before. Place any triangle on T-square edge.
   
2. Slide your left hand to hold both T-square and triangle in
   

   position.
   

   

   
   

   Draw a Vertical Line
   

3. Lean the pencil to the triangle.
   
4. Draw the line upward while rotating the pencil slowly.
   

   

   
   

   Draw a line at 45o with horizontal
   

   1. Place 45o triangle on the T-square edge and press them firmly against the paper.
      
   2. Draw the line in the direction as shown below.
      

Draw a line at angle 30o and 60o

1. Place 30o-60o triangle on the T-square edge and press
   

   them firmly against the paper.
   

2. Draw the line in the direction as shown below.
   

Draw the line passing through two given points

1. Place the pencil tip at one of the points.
   
2. Place the triangle against the pencil tip.
   
3. 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

1. Swing an arc of any radius whose centers at the vertex.
   
2. Swing the arcs of any radius from the intersection points between the previous arc and the lines.
   
3. 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