Home made Telescop mirror. Is it possible?

[Arugela]

https://www.youtube.com/watch?v=EV4AOo1nUMU


how could you go about making a real mirror like this for a Newtonian Or similar telescope? I want to make a big one but I have no idea where to start. I was thinking something like water mixed with maybe a fine metal like in metal liquids they play with with magnets to give it a shine and background color to reflect then add a solution while it's spinning to get it to harden. Is this realistic or possible. What other methods would be possible like this to make telescope mirrors at home?

Edited December 8, 2015 by Arugela

[*Aqua*]

IMO you won't be able to archieve the needed precision with this method. How do you know the mirror has just the right curvature and what optical properties like focal length?

I thing the easiest way to make a reasonable large mirror is to use a satellite dish and remove the paint. Then I would either paint or using electorplating to cover it with highly reflective material. After that you only need to polish it. The dish usually has a receiver arm so you know the focal point and where to attach a small mirror which reflects the light into an objective. (= You build a reflecting telescope.) Edited November 25, 2015 by *Aqua*

[Shpaget]

It's perfectly possible to do all the steps to make the mirror in your back yard, except the final reflective coating.
To get the good job on that one, you'll need some equipment that is beyond amateurs. However, there are companies that will do that relatively cheaply for you.

To make the mirror you need just some basic tools.
[url]https://stellafane.org/tm/atm/general/myths.html[/url]
[url]http://stellafane.org/tm/atm/index.html[/url]

Also, don't entertain the idea of the satellite dish. That's nowhere near good enough. Edited November 25, 2015 by Shpaget

[Arugela]

Is there a simple way to test focal point by using light the reverse way into the eyepeice and watch where it goes at the end of the telescope? couldn't you cap the top and get the light to fill to the edge of the telescope or something? If that sort of thing could work it could be good for adjusting adjustable casings and secondary mirrors or something.

[quote name='Shpaget']It's perfectly possible to do all the steps to make the mirror in your back yard, except the final reflective coating.
To get the good job on that one, you'll need some equipment that is beyond amateurs. However, there are companies that will do that relatively cheaply for you.

To make the mirror you need just some basic tools.
[URL]https://stellafane.org/tm/atm/general/myths.html[/URL]

Also, don't entertain the idea of the satellite dish. That's nowhere near good enough.[/QUOTE]

What about the idea of developing a liquid that becomes reflective. Or even reflective and translucent and having cheaper reflective surfaces on the back to help reflect light? Or is the back the worst place. Maybe with enough metal in the liquid you could make the metal sit in a way that makes the resen/material naturally reflective. (or even coat it after you make it with a liquid silver or aluminum coating that is super thin.)

Maybe very fine silver or quarts?!(what am I thinking of?) or whatever is reflective.

And if not maybe you could make a surface you could polish to get coated with reflective materials. Edited November 25, 2015 by Arugela

[*Aqua*]

It's not good enough? I assumed if it's good enough to receive and concentrate signals from a satellite thousands of kilometers away it should be good enough to be used as the base for a mirror.

[Elthy]

You dont need good resolution to from a TV satellite, only good signal strenght. A teleskop using one would propably recieve everything a smudge of light, maybe you could use that for spectroscopic analysis but not more.

[Shpaget]

Tolerances for satellite dishes are much poorer than for optical telescopes. Your dish could be banged up and have bird droppings all over it and still perform ok, something that would completely ruin an optical mirror.

Are [I]you[/I] able to develop the liquid that will become reflective once it solidifies? If not, are you able to pay someone the cost of development? The cost of such development would probably be such that you could buy a fully equipped observatory instead.

Mirror can't be translucent. The reflective surface must be on the front, not back (the first thing light hits must be the reflective stuff, not transparent glass).

Polishing and coating is the way it's done. You can grind, polish and figure the base yourself. It's usually done in glass. Then you pay a company that specializes in such work to coat it for you.

[Elthy]

Maybe you could reate such a coating yourself, e.g. with Tolens reagent, which applies silver to the surface.

[Arugela]

[video=youtube;Q90i31JIQ3M]https://www.youtube.com/watch?v=Q90i31JIQ3M[/video]

Is this bad for telescope mirrors?

[Shpaget]

Do you see those holes for the mounting bolts, those lines between strips, bubbles of air trapped under the foil and holes he poked in it to pop them?
Yeah, those will ruin the picture.

I already gave you the only way you can make a parabolic mirror that is good enough for optical telescope. There is no other way.

[Arugela]

[video=youtube;P_u9zjamBvs]https://www.youtube.com/watch?v=P_u9zjamBvs[/video]

I found this on grinding mirrors. I've seen videos along time ago that go into more detail potentially(On the grinding at least.), but I have to find them again.

Also found this:

[video=youtube;snz7JJlSZvw]https://www.youtube.com/watch?v=snz7JJlSZvw[/video]

I still think it would be cool to try to make a base for a mirror rotating liquid to make the concave... Edited November 25, 2015 by Arugela

[Elthy]

Maybe you could use something like a selfhardening epoxy. That would allow you to use motor to rotate it at room temperature.

[Kevin Kyle]

Here is what you are looking for. [url]https://stellafane.org/tm/[/url] Making a mirror isnt really too hard, the basics are you rub 2 pieces of glass together and eventually, you will have a mirror. They are tested with light and are of extreme precision. They arent even a perfect curve , more like a combination of curves blended together. Hopefully that link will work. There are many sites on this process. Be aware that working with glass needs certain precautions. It can be dangerous to your health. Im talking a relector type telescope mirror. There are others, lens based tele's are a different beast.

[pincushionman]

You can absolutelely make your own mirrors. My brother was in the astronomy club at the University of Illinois, and they would build their own telescopes, having "polishing parties" to work the mirrors by hand. Don't know how they got them silvered, though. They may have been professionally front-silvered…or they may have taken advantage of the chemistry department. Edited November 25, 2015 by pincushionman

[Camacha]

[quote name='pincushionman']You can absolutelely make your own mirrors. My brother was in the astronomy club at the University of Illinois, and they would build their own telescopes, having "polishing parties" to work the mirrors by hand. Don't know how they got them silvered, though. They may have been professionally front-silvered…or they may have taken advantage of the chemistry department.[/QUOTE]

Agreed. I know polishing your own mirrors or optics is done regularly and can be done with very serviceable results. I think the silvering is generally left to professionals, but the grinding is mostly a tedious job that requires some experience to do right, but not a lot of complicated gear.

[Shpaget]

Someone who has made a few mirrors can make a very good one, comparable to good quality commercial ones, certainly better than those found in supermarket telescopes.
But even a beginner can make a decent smaller mirror if he follows the tutorials and takes his time. It's a slow process that can't be rushed.

[Kevin Kyle]

My 6 inch has a homemade mirror and its a great one. I probably couldnt afford to buy one that good. I didnt make it but I want to make a larger one. There are a few companies that coat mirrors, its not too expensive. Of course, reflector teles are the ones most commonly made and offer the most bang for your bucks. If you have some mechanical skills, you can pretty easily make your own. Read read and read some more.

You do realize that your going to see mostly just black and white, its not all colorful like the images you see but yet still fascinating. These days, amateurs do imaging that rivals what pros did only a few years or so back. It can be an expensive hobby or you can get buy on an amazingly small amount. You can see a great deal with your average binoculars if you simply know where to look. Sorry for straying a bit off the topic and for rambling on a bit. :)