Armillaries comes with interlocking spheres and spear like stick or gnomon. As the sun moves across the sky, the gnomon casts a shadow on the surface, which displays the time. They are usually made of brass, bronze or aluminum. Dimensions, materials and designs vary, but the installation instructions is same for all styles.
To set up this, first choose your location. Place it higher your sunny areas in your yard or garden to get direct sunlight and to give more accurate reading of the time.
The next thing you need to do is adjusting the base. You need to do two adjustment: horizontal and vertical. Horizontal means the sundial need to be paralleled with the ground. A screw attached with it will help you adjust this leveling. If you do not do this and the base is inclined, it will make the sundial reads incorrectly. Regularly check that the baseline, especially after frost and cold.
The next thing you need to do is position the gnomon or arrow like stick towards right direction. Configure the north from a copass and point the gnomon in this direction. For greater clarity, the gnomon need to pointed towards the geographic north not the magnetic north. But, as it is slightly difficult to calibrate true north,directing genomon towards magnetic north would be fine.
Guess you are still enthusiastic about pointing the genomon to actual north. Then, you must know that our north pole is not where a compass shows us; it is some degree of distance away from the magnetic north. For example, from Washington DC, this angle of declination is 21 degree east;the original north is 21 degree away to the east from the direction a compass is showing. If you want to know this inclination figure for your location, you need to find out your latitude and longitude from Google Earth and then find the reading from this website.
There is another way to do this, but not so mathematically precise way.Set the genomon by slightly moving its direction at exactly 12 AM, so that it cast no shadow. Because, at midday, a well installed solar clock will not cast any shadow. The sun will be directly overhead at midday it naturally will not cast any shadow directly beneath it.