Cast Aluminium Sundial

Design Brief

Design and make a Sundial to suit your home location Latitude which can be sited outside permanently in your community.

Materials Available

The main component (i.e. the 'Dial Plate') must be Sand Cast from aluminium using a one-piece pattern. Minor components may be added from any available material (e.g. stainless steel rod or brass plate for Gnomon, fixing screws, coloured polyester resign to fill recesses shaped to show numbers, numerals, symbols, shapes, lines etc.).

Considerations

• Where will the Sundial be located - (e.g. on a flat surface, a wall, a post, as part of another structure)?
• How can the Sundial be made weatherproof?
• Will it need to be vandal resistant?
• How accurate will it need to be?
• What limitations will Sand Casting impose on the design?

Research

• Which way should a Sundial face - does it matter?
• Why does Latitude of location matter?
• What types of Sundial are available?
• How are Sundials calibrated?

Ideas

• Find out about the various designs possible by Exploring Sundials in the DT Online Sundials section.

Design Development and Construction

• Use the DT Online Sundial Design Tools to work out the spacing or angles of your Hour LInes
• Construct a full-size Pattern of your Dial Plate and Gnomon support using MDF or similar materials.
• Any vertical sides should be given a slight taper to ensure the Pattern will withdraw from the mould.
• Ensure all inside corners are give a slight radius by using wood filler or painting with a good surface primer.
• Paint over to provide a good surface finish then follow the procedures for Sand Casting
• The Gnomon support may be a Split Pattern or cast using Odd-Side Moulding techniques.

• Remove the Sprues from the finished casting and machine surfaces where needed either with a Milling Machine or by Facing-off using a Centre Lathe with the casting fixed to a Face Plate.
• The casting may also be finished with Files and Emery Cloth or Wet or Dry Paper if machinery is not available.
• Drill and Tap the Gnomon support to receive fixing Machine Screws and the threaded Gnomon rod.

Testing and Evaluation

• How accurate a timekeeper is it?
• Are members of your community pleased with it?
• Is it installed in the best place?
• Monitor over time and judge if it is affected by weather or vandalism.