How do they make telescope mirror?

Making a telescope mirror. To start, a new mirror blank is “sanded” down to create a precise parabolic curve in a process called grinding. To do that, the blank is paired with a device called a grinding tool, usually made of glass, plaster, or ceramic.

How thick does a telescope mirror need to be?

Consider for example the dictum that the mirror of a reflecting telescope must be made of glass which has a thickness of at least one eighth of its diameter, and is said to be better still if it is as thick as one sixth of its diameter.

How can I make a cheap telescope mirror?

The sand is packed into a flask which is the kind of container for the sand. And it’s made out of cast iron. So you put the pattern in pack the sand. Around.

How long does it take to make a telescope mirror?

Just grinding the telescope mirror probably took 80-100 hours for me, but I was learning a lot and taking my time.

How can I make a 1000x telescope at home?

Things You’ll Need

  1. Cardboard telescoping mailing tube with a diameter of 50 mm and a length of 1,100 mm.
  2. Concave-convex lens (the objective lens) with a diameter of 49 mm and a focal length of 1,350 mm.
  3. Plano-concave lens (the eyepiece) with a diameter of 49 mm and a focal length of 152 mm.
  4. Coping saw.
  5. Box cutter.

How long do telescope mirrors last?

It is not at all uncommon for coatings to last 30 years or more. The main causes of mirror damage are constant exposure to moisture, contaminants through poor storage and, ironically, cleaning them too often.

How thin can mirrors be?

For home applications, mirrors are available in 1/8, 3/16, and 1/4 inch thicknesses. Ideally, you need to choose the thicker mirrors if you are looking for high quality. So if your budget can handle its cost, you should always go for a mirror that is a 1/4 inch thick.

Why telescope mirror is thick?

Mirror Thickness

While thickness adds to weight, cost and thermal cool-down time, it also adds to stiffness, and the mirror can hold it’s shape and not distort the light it is reflecting in a simple mirror cell. Thin mirrors need special flotation cells to prevent this distortion.

What is a telescope mirror called?

A primary mirror (or primary) is the principal light-gathering surface (the objective) of a reflecting telescope.

How do you grind a mirror at home?

How to grind a mirror for a telescope – YouTube

How long does it take to polish a telescope mirror?

STROKES: Use the Normal Stroke (1/3 Center-over-Center) for all polishing. TIME: A 6″ f/8 or 8″ f/6 mirror will typically be polished out in 6 to 12 hours or work, depending on mirror size and personal work style. This is very approximately one to two hours per inch of mirror diameter.

Why are telescope mirrors made of glass?

It is a very stable material and will hold its shape well for thousands of years. Glass can also be polished to a high degree of accuracy without having defects. Another major reason is the expansion properties are very favorable as well. Glass doesn’t corrode and is easier to mold into shape than metal mirrors.

Can you make a powerful telescope at home?

If you’re a budding astronomer, you’ll be pleased to know you don’t have to spend big bucks on a fancy telescope. Instead, you can make your own simple 9x magnification Galilean telescope at home. It’s affordable yet powerful enough to see many of the wonders the sky has to offer.

What makes a telescope powerful?

The most important aspect of any telescope is its aperture, the diameter of its main optical component, which can be either a lens or a mirror. A scope’s aperture determines both its light-gathering ability (how bright the image appears) and its resolving power (how sharp the image appears).

How are telescope mirrors coated?

In general, the primary mirrors of large telescopes are coated with a thin film of aluminum. The Gemini Observatory was designed specifically to perform with a mirror that is coated in silver.

When should you recoat a telescope mirror?

Steve says: “In general, more modern mirrors will very rarely require re-coating but so much depends on how they have been looked after, and there is certainly no standard length of time you should adhere to. It is not at all uncommon for coatings to last 30 years or more.

How thick is a mirror mm?

Mirrors are generally edged in one of three ways. They may have a polished edge which sees a clean, smooth edge to the mirror; they may be bevelled edge which sees a chamfer from the edge of the glass coming in approximately 25mm; or they may be framed. Standard mirror glass comes in 4mm & 6mm thickness.

What makes a quality mirror?

In order to make a mirror, a reflective material such as tin-mercury amalgam, aluminum, or silver has adhered to the back of the clear glass. Now a high quality mirror will have silver as its reflective coating. The mirror will also have a sealer and several coats of paint to prevent the silver from tarnishing.

What type of glass is used in telescopes?

SCHOTT SUPREMAX 33® is quickly becoming the material of choice for telescopes. The rolled borosilicate glass offers the same properties of SCHOTT BOROFLOAT® 33, such as: Low thermal expansion. High thermal resistance.

Which glass is used in telescope?

Optical glass is a high purity glass used in the production of lenses needed for high precision as in spectacles, telescopes, microscopes, cameras, etc.

How accurate are telescope mirrors?

The surface of a telescope mirror must be polished to its precise paraboloidal shape within approximately 1/25 of the wavelength of light. For typical blue light, that means a surface accuracy of order 15-20 nanometers (less than 1.0 x 10-6 inch).

How do you polish a mirror on a telescope?

DIY Telescope: Polishing the Mirror – YouTube

How are telescope mirrors polished?

The basic principle of polishing is to rub the surface with a disk-shaped tool, removing glass selectively from the spots that are too high. A fine abrasive such as rouge (iron oxide) slowly removes glass, atom by atom, through mechanical and chemical processes.

How much magnification do you need to see Jupiter?

To look at planets like Jupiter and Saturn, you will need a magnification of about 180; with that you should be able to see the planets and their moons. If you want to look at the planet alone with higher resolution, you will need a magnification of about 380.

Which lens is used in telescope?

The telescope must have one convex lens as one of the two lenses since the convex lens is used to magnify the objects by bending the path of light.