Definition of Terms
- Axis – line about which a body turns or rotates
- Design – drawing showing the plan, elevations, sections, and other features.
- Detail drawing – separate drawing showing a small part of a machine or structure
- Dimension – definite measure shown on a drawing in detail
- Isometric Drawing – drawing which resembles a respective drawing
- Orthographic Projection – arrangement in a drawing of the three principal views of an object
- Perspective Drawing – the representation of an object on a plan surface, pertaining to materials, styles and finish presented as to have the same appearances as when seen from a particular viewpoint
- Projections – the cutting out of any part or any member of a structure
- Reduced – made smaller than the actual size as in the size of object
- Scaled Drawing – drawing plan made according to a scale, smaller than the actual work
- Sketch – freehand drawing of an object
- Specification – written instruction to the worker containing all the information
Learning Outcome 1:
|
Analyze signs, symbols and data
|
Information Sheet 1.1
DRAWING SIGNS AND SYMBOLS
Alphabet of Lines
In sketching orthographic drawing, certain conventional lines are used for a definite purpose. These lines are commonly called Alphabet of Lines.
Uses of Alphabet Lines:
- Construction line - Very light line used to “block in” an object. These lines are made so light that little or no erasing is needed. They serve as base for darkening in the permanent line
- Borderline - Heavy, solid line used to frame in the drawing
- Visible line - A medium line used to show edges and contours not visible to the eye.
- Invisible line - A medium line used to show edges and contours not visible to the eye.
- Centerline - A light line used as axis of symmetry. Used for center of circle and arcs. Sometimes the symbol is shown
- Dimension line - Light thin lines used to show the sizes of the object. Extension lights start about 1/16” from visible or object line. The dimension line is broken near the center for the dimension.
- Long break line - Heavy line draws freehand for same purpose as long break.
Learning Outcome 2:
|
Interpret technical drawings and plans
|
Information Sheet 2.1
CENTER TABLE OF COMPONENTS
- Legs – 4 pcs. 45 mm x 45mm x500 mm wood (tanguile)
- Rails – (short) 2 pieces 25 mmx70 mm x 600 mm
- Rails – (long) 2 pieces 25 mm x 70mm x 800 mm
- Top – 1pcs 25mmx600 x 800mm plywood/ plyboard
Assemblies Joints
- Mortise and tendon joint – for the rails and legs (see details on the attached working drawing)
Dimensions and specification (See dimensions and specifications on the attached working drawing)
- Legs must be tapered.
- All joints must be filled with glue.
- All wood used must be tanguile.
- All dimensions must be in millimeters.
Learning Outcome 3:
|
Apply freehand sketching
|
Information Sheet 3.1
STEPS IN SKETCHING AN ISOMETRIC BOX
1. Draw a vertical axis.
2. Draw left and right axis.
3. Determine the width and length of the box and then draw a vertical line
4. Draw a left and right axis to the determined height of the box.
5. Project a line parallel to the left and right axis
6. Label the box to determine the top, front and the right side view
Steps in Sketching Orthographic Drawing
1. Study the object to be drawn (See isometric drawing on operation sheet (3-1)
2. Draw the top view, front view and the right side view
2. Draw the top view, front view and the right side view
3. Draw a simple drawing using block as model. Try to study the given view.
Steps in Sketching Isometric Drawing of a Given Orthographic Figure
Additional Information:
|
|