Parabolic reflector is one of the best item to be used to harness the light and heat from the sun. This also use as a solar cooker.
In this project, we will make a simple parabolic solar cooker made from cardboard. Then later, we will add simple solar tracker to help the alignment to the sun.
Step 1: Prepare the Materials
* Cardboard box or boxes with the same sizes.
* aluminum foil or mylar sheet
* knife or cutter
* 2 pcs of key rings
* bottle ring
* paper clip
Step 2: Make a Parabola Pattern
Draw a parabola on the side of the box.
To make a parabola:
1. Using pencil or stick, punch a hole to the desired focal point in the box. Maybe 10cm to 15cm from the bottom of the box to focal point. Let the pencil or stick stay in the hole.
2. Lay down the rod to the box for a desired distance from focal point to the top of parabola. This will serve as guide to draw a parabola.
3. Tie the string to the two key rings as shown in the image. Then insert to the rod.
4. Slowly draw a parabola. The marker should always align with the ring on the side where it is being drawn until the center is reached. Then continue with the other half of the parabola.
5. Cut the parabola. Please refer to the image. This will serve as a template for the other parts.
Step 3: Box Frame
Using the template from the previous step, draw and cut both opposite side of the another box with the same width of the template.
Step 4: Prepare the Ribs
Cut the 8 to 15 pcs of parabolas using the template. The quantity is defending with the size of the the box used. Place these in the frame.
Cut rectangular shapes of cardboard. Use these as spacer to each rib's gap.
Step 5: Attach the Reflector
Glue the aluminum foil or mylar sheet on top of the parabola.
Now the parabola cooker is ready. Lets add a tool to locate the sun's perfect angle. We will make a solar tracker. Go to the next step.
Step 6: Make the Solar Tracker
1. Cut a 5cm by 10cm cardboard . And a 5cm by 5cm cardboard.
2. Draw a cross as shown above.
3. Place the paper clip to the center of the cross. This will serve as a needle of the tracker.
4. Glue the 5cm by 5cm cardboard to the bottom of the tracker to secure the needle.
5. Place the bottle ring to surround the area of the tracker.
6. Fold the tracker in half. Will form a right angle as shown above. Glue to secure the angle.
Now this is ready to attach to the cooker.
Step 7: Attach the Solar Tracker
Paste the solar tracker on the side of the parabolic cooker. The place is not specific. You may choose any where in the box as long as the tracker is parallel with the base of the parabola.
Step 8: Done
Start cooking. Use any dark glass or cookware with this cooker as long as it fits. The darker the better.
From time to time, align the cooker using the tracker. If the shadow of the needle is in the middle of the tracker, it is aligned.