Can you make a telescope mirror?
Making a telescope mirror is one of the most satisfying and sublime joys you will experience. It’s also arguably the most accurate surface made by man or machine. If the mirror is expanded to the size of a football field, then the mirror’s surface will be smooth to 1/1000 inch or 1/30 millimeter!
Why are telescope mirrors made of glass?
Glass has a very low coefficient of expansion. This means that changes in temperature have very little effect on it. Overall glass is an excellent material for making telescope mirrors because it can be ground very accurately, will maintain it’s accuracy and will not expand or contract with temperature changes.
How can I make my telescope bigger at home?
To make a simple telescope at home, you will need the following:
- two magnifying glasses – perhaps 1 – 1.5 inches (2.5-3 cm) diameter (it works best if one is larger than the other)
- a cardboard tube – paper towel roll or gift-wrapping paper roll (it helps if it is long)
- duct tape.
- scissors.
Which mirror is used in telescope and why?
The Reflecting Telescope or Reflector uses a concave mirror as the telescope’s Primary Objective, rather than a lens or lenses. The type of reflector depends on other system mirror(s), called the Secondary Mirror. A Compound or Catadioptric Telescope uses a combination of Refractor and Reflector characteristics.
What are telescope mirrors made out of?
The primary mirror in most modern telescopes is composed of a solid glass cylinder whose front surface has been ground to a spherical or parabolic shape. A thin layer of aluminum is vacuum deposited onto the mirror, forming a highly reflective first surface mirror.
Can you grind a mirror?
Just put the tool on the bottom and the mirror on top, then grind until the sagitta decreases. As you do this, sometimes the mirror and tool won’t fit together perfectly and there will be bubbles in there – that’s okay at this step, as you work through fine grinding though, seeing these can be a sign of a problem.
How do you make your own telescope mirror?
[Fig 3]I attached a round piece of wood to the base of a fishing boat chair. This allows me to rotate the glass so the diamond blade will make a spherical shape into the glass. [Fig 3]Here is a picture of the turntable attached to my drill press along with the diamond blade in the chuck. This photo doesnt show the piece of wood.
How big is an 8 inch telescope blank?
This is a full-thickness, 8 inch diameter telescope mirror blank that I made myself. This web page will show how I did it. Why make my own mirror blank? Why not?
Can a shallow mirror be used in a deep telescope?
If you make the centre deep, you will end up with a fast telescope (e.g. F/D = 4) well suited for deep sky observations. On the opposite, a shallow mirror (e.g. F/D = 8) will be performing very well on planets and the moon. The theory behind grinding is that you can remove glass as long as you use a material with a higher hardness.
What’s the best way to remove glass from a telescope?
The theory behind grinding is that you can remove glass as long as you use a material with a higher hardness. Telescope makers use silicon carbide powders (a.k.a. carborundum) for this task. It is cheap and comes in various size (can range from #36 to #500). To be effective, the abrasive needs to be rubbed against the glass with a lot of pressure.