Parabolic mirror collecting sun (1)

The mirror surface is pt. 130 mm radius. It collects about 40 watts of sunlight. The focal length is 300 mm. The mirror itself is not really that big, but the good thing about this mirror is that the surface form is very precise. The surface error should be less than a few micrometers. As such it can generate a spotsize of about 3-4 mm in diameter with a very high intensity.

It is made from a solid aluminum disc that is 300 mm in diameter and 25 mm thick.
It is made on a high precision cnc lathe that cuts the surface with a diamond creating a highly reflective surface with no need for subsequent polishing. The last cut removes 2 micrometers off of the surface.

Future projects on this mirror involves making the blank surface go all the way out to 149-150 mm radius and pulling the focal point into about 275 mm distance. This way the mirror will collect 30% more energy as well as reducing spotsize to theoretical 2.75 mm diameter. Spot intensity should be alomst doubled by this.

Of things I tried to heat up so far :

Empty soda can. This melts and as he melted point is moved it will eventually cut the can.

Flint stone heats up till the point where it fizzles and cracks into small sharp bits.

Brick stone - the spot makes a black liquid mass pour out of.

Melts a mesh of thin copperwire into a solid mass.

Category:

Entertainment

Tags:

• Parabolic
• mirror
• sun
• burn

[rainxxxx]

how do you do that?

[alex2143]

Yup. And it's collecting sunlight, too!

[DrkOne633]

How much was it? I've built a tower (wooden) to house a mirror, but I do not know where to get one/or how much it will cost for a big one.

[Allmuddled]

Parabolic mirror