1. Technological Design
Technical Drawing

2. Why Draw ? Universal Language or the Language of Industry
“A Picture is worth a 1000 words”

3. Line Types Construction Object Hidden used to build the drawings
very light solid line ________
Object
used to show the object
thicker, darker solid line _______
Hidden
used to show hidden features of an object
thin dark dashed line _ _ _ _ _ _ _ _

4. Center lines
A center line represents an axis of symmetry
___ _ ___

5. Sketching “back of the envelope” work Created freehand
Must be done neat and clear
use proper perspective
Must be done quickly and efficiently

6. “it is directly proportional to the actual object”
Drawings & Scale
Draw an object to scale…..
“it is directly proportional to the actual object”
Scale:
1 : 1
Is proportional to
1 Unit of Actual Object
1 Unit on Paper

7. DRAWING IS 10 TIMES SMALLER THAN THE OBJECT
Reduced Scale
Scale:
1 : 10
Is proportional to
10 Unit of Actual Object
1 Unit on Paper
DRAWING IS 10 TIMES SMALLER THAN THE OBJECT

8. DRAWING IS 10 TIMES LARGER THAN THE OBJECT
Enlarged Scale
Scale:
10 : 1
Is proportional to
1 Unit of Actual Object
10 Unit on Paper
DRAWING IS 10 TIMES LARGER THAN THE OBJECT

9. Hand drawing – Sketching to scale
Plan your use of space
Choose the appropriate scale
Use the grid on the paper to draw to scale
Label the drawing clearly using good hand lettering skills

10. Sketching to scale–Basic steps
Build a frame

11. Sketching to scale–Basic steps
Block in overall sizes for each detail

12. Sketching to scale–Basic steps
Add the details

13. Sketching to scale–Basic steps
Darken the lines

14. True measurements are made along three major axes, which are:
ISOMETRIC PROJECTION
True measurements are made along three major axes, which are:
VERTICAL
30 degrees up to the LEFT
30°
30°
30 degrees up to the RIGHT
30°
Drawing object to actual measurement

15. ISOMETRIC PROJECTION
The basic procedure used in drawing isometrics is to use an isometric grid.
Next, draw all lines along the three major axes.

16. ISOMETRIC PROJECTION
When sketching, use isometric grid paper as a guide.

17. A circle drawn in isometric
has the shape of an ellipse on any of the three faces.