If you hold loosely two tips of any rope, especially a chain (because it is heavier than a rope), it gives a parabolic shape. So you don't have to calculate for drawing.
I just googled it and the curve is not parabola, but actually catenary curve, which appears to have wider angle of curve the further to the ends. The wider areas would not be contributing to the focal point of the rest of the mirror. Perhaps you could sketch out the real parabola shape by eyeball after tracing the rope.
I chose cement because it remains a long time, even in rainy weather. So you can make several reflectors one after the other. But I actually also used gypsum (see 8:00 - 9:40) because it can be sanded finer than cement. Perhaps I should have used the term "plaster" instead of "gypsum"; it's probably just a translation error, sorry.
How did you calculate the parabola? What was the formula? It doesn't look right, does it have a tight focus. I looked at your pdf, but a formula didn't jump out at me.
The formula is y=0.5.x.x/f, but I see that I made an error in the pdf-Document. I take all the contents about the solar cooker from the Internet until everything is fixed. Sorry and thanks for advising!
أشكركم على مديحك! إذا كنت تصنع طباخًا شمسيًا ، فسأطلب منك مشاركة تجاربك معي. قريباً سيكون هناك وصف لطباخ ورقي يعمل بالطاقة الشمسية على هذه القناة. مع أطيب التحيات!
Danke für die Idee vom Chrom-Spray! Ich habe kürzlich einen solchen Spray gekauft und Tests gemacht. Gemäss Internet-Recherche gibt es sehr unterschiedliche Qualitäten, was den Glanz und die Wasserfestigkeit anbetrifft. Der von mir gekaufte Spray hat die Unebenheiten des Untergrunds in keiner Weise ausgeglichen, es ist also noch mehr als beim Aufkleben von Alufolie wichtig, dass der Untergrund möglichst schon spiegelglatt ist. Auch von Vorteil ist es, wenn der Untergrund nicht saugfähig ist. Schliesslich war mein Spray auch bei perfekt spiegelglattem Untergrund etwas gräulich und daher weniger reflektierend als Alufolie. Ich werde aber noch weitertesten, und wenn ich das „Ei des Kolumbus“ finde, so werde ich es auf meinem RU-vid-Kanal oder meiner Webseite (www.cumaru-pe.com.br) kommunizieren.
What the actual hell did I just watch? I want the 5 minutes I wasted of my life back! There is a reason that not every man should try building things. You wasted materials and time on a project that can be easily done in a fraction of the time with far less effort.
I'm sorry you wasted 5 minutes of your life, but it's not my fault because I didn't ask you to watch the movie. By the way, I am very curious about your suggestions for improvement! Greetings!
