Easy and accurate three dimensional drawing
What is isometric drawing
An isometric projection belongs in the group of drawing methods called 'axonimetric' drawings. It is also called a 'paraline' drawing because it uses three groups of parallel lines to construct it.
Isometric drawings are set at 30 degrees to the horizontal and use a 30/60 degree set square.
A convenient projection
Isometric drawing is a projection. This means that the planes of an object are projected onto three sloping planes. The best thing about Isometric drawing is that each plane is in the same angle relative to the 'picture plane'. What does that mean for us?
This means that because each view has the same amount of distortion (actually 'shear'), we can measure the length, width and height of things using real measurements. We can set up our drawing using the same measurements we used for a 3rd Angle Orthogonal drawing.
Being able to set out a drawing with real measurements is fantastic for students and designers, because when we want to test our ideas for product designs, to see how they would look if constructed, we can do it with certainty that the view is realistic.
3rd Angle explained
techniques for isometric
ORTHOGONAL AND ISOMETRIC
SKETCHING ON AN ISOMETRIC GRID
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DRAWING ALL THE LINES
Consider the following drawing. The crate is shown in blue and the finished drawing is shown in red. When you are drawing your crate, make sure you draw all the lines, even the ones at the back you think you won't need. These are needed as you will need to measure from hidden points to calculate the position of features of the object.
Circles in isometric
Circles appear as ellipses in isometric projections. An ellipse is a kind of oval. We have to draw them with the correct proportions between the long and short axis (length and width) and align them at the correct angle from the horizontal in our drawings.
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Using an isometric template
As you move onto more complex drawings you will want to use an isometric ellipse template. These can be especially useful in tests. However, you must take care to learn how to align the small lines to the axes of the ellipse.
It might sound like a long way around, but you still need to draw the square to calculate axes before you apply the template.