Isometric Drawing - Paper 1 and Paper 2 Flashcards
What is pictorial drawing?
A method of representing a three dimensional image on a two dimensional surface.
What is the purpose of a pictorial drawing?
It is a means of enabling a person without any technical training to visualise a design or a graphic with relative ease.
What is the recommended angle for hatching in isometric drawings?
75° to the horizontal
When should the angle of the hatching lines be changed to 60 degrees in isometric drawings?
When the hatching lines lie parallel to a prominent, visible outline or to other adjacent lines in the drawing.
Name 2 types of isometric sections.
full-section isometric drawing
half-section isometric drawing
What is a full section isometric drawing?
Only half of the object is removed and it is the half which hides the cut surface.
When do you use a half-section isometric drawing?
In cases where it is necessary to describe both the exterior and the interior shape of an object together.
What is a half-section isometric drawing?
Only a quarter of the object is removed and the two cut surfaces are then hatched in alternate directions.
When do you use an exploded isometric drawing?
When you need to show how the parts of an assembly fit together.
What is step 1 for drawing an isometric circle?
Draw an isometric box equal in size to the diameter of the circle.
What is step 2 for drawing an isometric circle?
Divide the box into 4 equal sized quadrants.
What is step 3 for drawing an isometric circle?
Short corners - With B as the centre and B3 as the radius scribe the arc.
What is step 4 for drawing an isometric circle?
Long corners - Join the corners AC
What is step 5 for drawing an isometric circle?
To find the centres E and F, join 1 to D to find centre E, and 3 to B to find centre F.
What is step 6 for drawing an isometric circle?
Complete the isometric circle by scribing the arcs E1 and F3.
How many isometric planes can an isometric circle be drawn in?
3
What does a circle form when it is drawn isometrically?
An ellipse.
How many methods are there to draw parallel isometric circles?
2
What is the first method for drawing parallel isometric circles?
Draw a second isometric grid the offset distance from the circle and repeat the drawing process for an isometric circle.
What is the second method for drawing parallel isometric circles?
Project the centres of the first isometric circle back the offset distance.
What should you remember when you are drawing isometric parallel circles?
Remember to include the centre lines in circular features.
When do you use an auxiliary method to do an isometric drawing?
When the dimensions on an isometric drawing do not describe the exact position of the ends of a non-isometric line.
What does the auxiliary view method require?
It requires that a non-isometric line or feature, such as an angle, is drawn in a flat or orthographic plane.
What steps are followed for drawing non-isometric lines using an auxiliary view?
- Draw a box around the line or feature.
- Determine the size of the box on the flat plane.
- Draw the box isometrically and transfer the feature from the flat plane to the isometric plane.
