Drawing Abilities Teacher
Solid Cylinder cut at an angle
© J Lewis 2004
Orthographic projection
Draw the Plan and Elevation of the cylinder, which is cut at an angle of 30 °
Plan
Elevation
© J Lewis 2004
Drawing generators
Divide the plan into 12 equal generators at 30 °, number these as shown
11
12
1
10
2
9
3
4
8
7
6
5
Plan
Elevation
© J Lewis 2004
Inserting reference points
Project the vertical generators down to the Elevation and number as shown
11
12
1
10
2
9
3
4
8
7
6
5
Elevation
98 7 6 5 43
(10)(11)(12)(1) (2)
© J Lewis 2004
Starting the End Elevation
Construct the outline of the End Elevation, point 3 at the front and the generators shown
11
12
8
1
10
2
9
3
4
8
7
6
5
9
10
7
11
12
6
5
1
4
3
2
Elevation
End Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Drawing horizontal generators
Construct horizontals where the vertical generators cross the sloping top of the
Elevation
12
9
11
8
1
10
2
9
3
4
8
7
6
5
10
7
11
12
6
5
1
4
3
2
Elevation
End Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Marking out the shape
Now mark the End Elevation. Points are found where horizontal lines cross similar
marked generators.
12
9
11
8
1
10
2
9
3
4
8
7
6
5
10
7
11
12
6
5
1
4
3
2
Elevation
End Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Drawing the ellipse
Draw an ellipse passing through the marked points
6
Elevation
3
End Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Finished End Elevation
Plan
Elevation
End Elevation
© J Lewis 2004
Surface Development
Project horizontals from the Elevation and step off to circumference length in 12 steps
7
6
5
98 7 6 5 4 3
(10)(11)(12) (1) (2)
3
4
5
6
7
8
9
10 11 12
1
2
Elevation
© J Lewis 2004
3
Marking points
Mark the reference points carefully as shown below
7
6
5
98 7 6 5 43
(10)(11)(12) (1) (2)
3
4
5
6
7
8
9 10 11 12 1
2
3
Elevation
© J Lewis 2004
Joining the points
Join the points with a smooth curve
7
6
5
98 7 6 5 43
(10)(11)(12) (1) (2)
3
4
5
6
7
8
9 10 11 12 1
2
3
Elevation
© J Lewis 2004
Finished Surface Development
11
12
1
10
2
9
3
4
8
7
6
5
Plan
98 7 6 5 43
(10)(11)(12) (1) (2)
Elevation
3
4
5
6
7
8
9 10 11 12
Surface Development
1
2
3
© J Lewis 2004
Dealing with Cones
Cones are dealt with in a similar way to cylinders
The Plan and Elevation of the cone, which is cut at an angle of 30 ° by the
plane A – A are shown below
Plan
A
A
Elevation
© J Lewis 2004
Drawing generators
Divide the Plan into 12 equal generators at 30 °, number these as shown
11
12
1
10
2
9
3
Plan
4
8
7
6
5
A
A
Elevation
© J Lewis 2004
Inserting reference points
Project the vertical generators down to the Elevation and number as shown
11
12
1
10
2
9
3
4
8
7
6
5
98 7 6 5 43
(10)(11)(12) (1) (2)
© J Lewis 2004
Drawing Surface Generators
Draw surface generators as shown
4
8
7
6
5
98 7 6 5 43
(10)(11)(12) (1) (2)
© J Lewis 2004
Starting the End Elevation
Construct the outline of the End Elevation, point 3 at the front and the generators shown
11
12
8
1
10
2
9
3
4
8
7
6
5
9
10
7
11
12
6
5
1
4
3
2
Elevation
End Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Starting the End Elevation
Construct surface generators on the End Elevation as shown
11
12
8
1
10
2
9
3
4
8
7
6
5
9
10
7
11
12
6
5
1
4
3
2
Elevation
End Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Drawing the End Elevation
Construct horizontals as shown
Elevation
98 7 6 5 43
(10)(11)(12) (1) (2)
End Elevation
6 5 4 3 2 1 12
(7) (8) (9)(10)(11)
© J Lewis 2004
Drawing the End Elevation
Draw a smooth curve as shown on the End Elevation
End Elevation
© J Lewis 2004
Starting the Plan
Construct the lines shown from the Elevation up to the Plan
11
12
1
10
Plan
2
9
3
4
8
7
6
8
5
9
10
7
1
6
5
1
4
3
Elevation
© J Lewis 2004
2
Completing the Plan
Transfer the measurement on 6 – 12 on the End Elevation to the same generator
on the Plan and draw a smooth curve as shown.
11
12
1
10
Plan
2
9
3
4
8
7
6
8
5
9
10
7
11
12
6
5
1
4
3
2
End Elevation
Elevation
© J Lewis 2004
Finished Orthographic Projection
A
A
© J Lewis 2004
Surface Development
Step off to circumference length in 12 steps along an arc with the same radius as
generator 3 as shown – this is a true length of side
Mark off the true lengths of each of the generators as shown and draw the surface
development
3
2
1
12
11
10
9
Elevation
8
3
98 7 6 5 43
(10)(11)(12) (1) (2)
4
5
6
7
© J Lewis 2004