I needed a way of pointing my solar cookers directly at the sun and came up with and made the following sun finder (sometimes called a solar finder.) I later found out that this design is commonly used for astronomy. You simply attach it to the solar cooker, or whatever you want to aim at the sun, and line it up as shown below.

Homemade/DIY sun/solar finder from the front.
Homemade/DIY sun/solar finder from the front...
Homemade/DIY sun/solar finder from the rear.
... and from the rear.
How the sun/solar finder works.
How the sun/solar finder works.

How to test the alignment of a sun finder

1. Place a hard covered book on the floor with the bottom or top edge lined up with a shadow.
1. Place a hard covered book on the floor with the bottom or top edge lined up with a shadow.
2. Hold the sun finder on the edge of the book. Line it up with the shadow too.
2. Hold the sun finder on the edge of the book. Line it up with the shadow too.
3. Angle the sun finder and book cover upward until the light meets the marker/hole in the back plate of the sun finder. If it doesn't line up then you need to fix it so it does.
3. Angle the sun finder and book cover upward until the light meets the marker/hole in the back plate of the sun finder. If it doesn't line up then you need to fix it so it does.

The sun finder attached to a solar cooker

The photos below show the sun finder attached to a solar cooker. A hole was made in the front of the solar cooker to allow the sun through. The sun finder was attached to the solar cooker by simply wrapping wire around it.

Notice the two ways you can use it. You can look at the bright spot on the front of the back plate as in the first photo. Try to get the spot to disappear through the hole. Or you can look at the bright spot shining through the back plate as in the second photo. Again, line it up with the hole. A hole is used instead of having a circle drawn on the plastic in case you want to shine the spot on something else behind the sun finder, for example, a photo diode that causes an alarm to go off when the light is no longer on it meaning it's time to move the solar cooker.

Looking at the sun finder from the front. Bright spot shining on the back plate.
Looking at it from the front. Bright spot shining on the back plate.
Looking at it from the back. Bright spot shining through the back plate.
Looking at it from the back. Bright spot shining through the back plate.

Video of sun finder with full construction details, alignment testing and demonstration with solar cooker

For more sun finder, and sun aiming tricks...

For more ways on this topic see this detailed page on different tricks for lining things up with the sun.

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