In this instructable I show you how to make a miniature sundial.
The basic stuff you need is:
- A wooden board (for example 15mm x 10 mm: the clock would be big enough to see the time and small enough to be moved easily but it’s up to you to choose other dimensions.)
- A pin (about 5 ou 6 cm)
- Two small door hinges
- Four screws
- A tiny compass
- A copper wire (easy to find in electric wires)
- Super glue (for both wood and copper)
Besides you will need basic craft stuff. All the above can be found online or in grocery stores.
Step 1: Build the Style of the Sundial
The style is basically the stick in the middle which makes the shadow on the clock.
As the sun is more or less high in the sky during the year, the shadow of a pin randomly hammered on the board will not give the right hour. Your stick must be parallel to the axis of rotation of the earth. To do so you need to find the right angle between the board and the pin.
Since the sundial is miniature you might want to move it from one place to another but the angle depends on where you are on Earth.
With just a pin, two door hinges and a few screws I propose a way to build something to easily change the angle of the pin :
Take a door hinge, cut it in half with a hacksaw to just keep a part of the hinge.
Pinch the pivot of the other hinge to make it difficult to close or open. In this way you will be able to choose the angle easily.
Use the previously cut part to screw the pin with the other hinge. Make sure to screw it tight so that the pin cannot move.
The pin I used was old so I have painted it in black but it will be cheaper to use a new and bright pin.
Step 2: Prepare the Wooden Board
Draw a circle on the left side of the board (9cm of diameter should be enough). Use the circle to draw a clock. Spot every 15° portion which represents an hour.
Since you won’t use your sundial by night you can just draw a part of the circle to spare some space. I have just kept hours between 4 AM and 8 PM.
Screw the first part (the pin with the door hinges) in the middle of the circle. Make sure the pin is perfectly parallel with the “12/24 hour” axis of the circle.
Then write the 6, 9, 12, 15 and 18 hours in roman numeral. If, like me, you’re not that much of an artist I recommend you draw parallel lines of 1cm height and mark dots every 3mm. In this way you will just have to link the dots together and you won’t mess everything up.
Cut the copper wire in small parts of three different sizes. Using the glue put the copper parts around the clock. Put the big ones on the 6, 12 and 18, the medium ones on 9 and 15 and the small ones on the other hours.
Once the copper parts are glued on the board it is hard to erase the pencil marks so erase it before and just keep dots to know where to glue the copper parts.
Step 3: Make a Hole to Put the Tiny Compass
I have thought about this part at the end but you should do it just after step one. It is easier to manipulate the board without anything on it. Besides if you don’t have a drilling machine and are not used to work with wood you’re likely to screw it up, which is bad if you have already made it to this step.
On the bottom left corner, draw a circle of the same diameter as the compass. Let a few milimeters between the circle and the corners. Then carefully dig a hole with a wood chisel. Start with a small one and make it larger and larger until the compass just fit in it.
If you have a drill of the right dimeter use a drilling machine. It will be easier and cleaner.
Once the hole is big enough, put the compass in it. Since the hole and the compass are of exactly the same diameter no glue is needed.
If you’ve worked with a wood chisel the ridge will not be as beautiful as you wish. To make it up cut another part of the copper wire and roll it up around the compass. The connection between the two sides of the wire will be useful to find the “north/south” axis.
Draw a line parallel with the axis of the pin passing trough the centre of the compass. Put the copper part around the compass so that the gap is on the line, pointing to the top of the sundial.
Step 4: Set the Right Angle and Orientation
The angle between the wooden board and the pin must equal to the latitude of your town. Use a protractor to set it up.
For instance, the latitude of Paris is 48.8° north so I must set an angle of 48.8°.
Once all the above is done, turn the sundial so that the south arrow of the compass is pointing to the small gap of the wire copper.
If you did well and I understood how a sundial works it should give you the right hour. :)