Ellipse – Trammel method An Ellipse is a squashed circle sometimes called an oval. There are a number of ways to produce one this presentation deals with the trammel method.

Page Layout - 1cm Border 1cm Name Block 2cm Indent

Draw in construction lines a cross which divides your page into quarters. Measurements are give below for use on A3 paper. 13cm – 130mm 19cm – 190mm

Measuring out from the centre of the of the cross mark the 4 points shown using the dimensions given. 12cm - 120 18cm – 180mm 18cm – 180mm 12cm - 120

Position the trammel on top of the horizontal axis so that the end corner touches point A. Label this mark number 1 1 A B Draw an arrow on the trammel indicating the corner touching point A. Draw a mark on the trammel to indicate the vertical centre line at point B.

C Position the trammel next to the vertical axis so that the corner with the arrow indicates point C. 1 Label this mark number 2. 2 A B Draw a mark on the trammel to indicate the horizontal centre line at point B.

Pivot the trammel so that marks 1 and 2 stay on the vertical and horizontal axis. Mark with a small dot at the corner of the trammel with the arrow 2 1

As you pivot the trammel mark 2 will slide along the horizontal axis and mark 1 will slide up the vertical axis towards the centre. Each time you pivot and slide the trammel, mark a small dot at the corner with the arrow. 2 1

The closer the dots are together the easier they will be to connect to construct the ellipse. 2 1

2 1

2 1

2 1

2 1

When the trammel is lying parallel with the horizontal axis you will have completed a quarter of the ellipse. 2 1

To begin the next quarter of the ellipse you repeat the process of sliding and pivoting the trammel and marking with a dot at the corner with the arrow. 2 1

This time mark number 1 will move up the vertical axis and mark number 2 will slide along the horizontal axis back towards the centre. 2 1

Remember the closer your dots are together the easier they will be to join when you draw in the ellipse. 2 1

2 1

2 1

2 1

2 1

You will have completed the second quarter of your ellipse when the trammel lies parallel with the horizontal axis and mark number 2 is in the centre. 2 1

Using the same techniques of slide, pivot and mark, complete the full ellipse. 2 1 Remember marks 1 & 2 on the trammel must be on the vertical and horizontal axis at all times for the ellipse to be accurate.

When your ellipse is fully mapped in dots you can very carefully connect them using a light construction line.

It is important that you try to keep the ellipse curve as smooth as possible

The shape of the curve will change as you move around the path of the ellipse

When you have produced a smooth clean full ellipse you will need to carefully draw over your construction line with a fine line black pen