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Robert_old
2002-Jan-02, 12:24 AM
Reading through some of the posts on this site I came across this webpage posted by someone:

http://www.geocities.com/telescope1999/14-5inch.html

I did not think one could build a scope without special tools!

aurorae
2002-Jan-02, 08:31 PM
Most people buy the mirror already made.

That reduces the time needed to build a scope from a major ongoing project to a few weekends.

On the other hand, there are a few people that really like to push glass and become very expert in it.

There are "ATM" groups on the web and email. (ATM= Amateur Telescope Making)

Russ
2002-Jan-03, 10:08 PM
On 2002-01-02 15:31, aurorae wrote:
Most people buy the mirror already made.


You must travel in different circles than I. All of the people I know, who have made a scope, made the mirror. In fact most of them look down their noses at folks who stoop to buy a pre-fab secondary mirror. Their reasoning is that only rank amatures would want to look through 1/4 wave optics instead of 1/10th wave. Too /phpBB/images/smiles/icon_cool.giffor you. /phpBB/images/smiles/icon_rolleyes.gif

(edit to correct code)

<font size=-1>[ This Message was edited by: Russ on 2002-01-03 17:10 ]</font>

Donnie B.
2002-Jan-04, 12:31 AM
My dad built a 6" reflector when I was in high school, including grinding his own mirror. Unfortunately, it didn't come out too well, and he ended up buying one anyway.

I remember an impressive view of the moon in that flawed mirror, though... unsilvered (he never did have it coated) but still incredibly bright.

Sadly, I wasn't able to grab that scope when he decided to get rid of it. All I have is binocs... /phpBB/images/smiles/icon_frown.gif

aurorae
2002-Jan-04, 04:55 PM
On 2002-01-03 17:08, Russ wrote:
You must travel in different circles than I. All of the people I know, who have made a scope, made the mirror


There still are a lot of folks that love to grind mirrors, but the vast majority of people that build Newtonian scopes in the US now buy commercial mirrors.

As to quality, there are a lot of premium mirror suppliers (Pegasus, Galaxy, Nova, Swayze, Zambuto, etc.) nowadays that produce really excellent products, better than most people could produce. Although, it is true that if an experienced mirror maker really wanted to make a superior mirror, they could spend as much time on it as they needed until it reached their idea of perfection. Commercial makers cannot afford to do this, they have to stop grinding at some point.

There are also a number of companies that mass produce mirrors (Meade, Discovery, and various Chinese companies that Orion buys from), they tend to produce decent but not excellent mirrors for lower cost, although they also have more variation in the quality of their mirrors.

Russ
2002-Jan-04, 05:20 PM
On 2002-01-04 11:55, aurorae wrote:

As to quality, there are a lot of premium mirror suppliers (Pegasus, Galaxy, Nova, Swayze, Zambuto, etc.) nowadays that produce really excellent products, better than most people could produce.

As you seem to know alot about this, maybe you could answer some questions.

While the mirrors in my Meade LX-200 are fine for now, I assume they will oxidize over time.
1) Do you know the procedure for getting them buffed and recoated?
2) Does Meade offer this service? If they do they don't mention it in my instruction book.
3) Is there somebody better?
4) Do you send them the whole scope or just the mirrors?
5) Have you ever made a mirror? Was it worth it?

Thanks for anything you can tell me.

aurorae
2002-Jan-04, 08:36 PM
On 2002-01-04 12:20, Russ wrote:
As you seem to know alot about this, maybe you could answer some questions.

While the mirrors in my Meade LX-200 are fine for now, I assume they will oxidize over time.
1) Do you know the procedure for getting them buffed and recoated?
2) Does Meade offer this service? If they do they don't mention it in my instruction book.
3) Is there somebody better?
4) Do you send them the whole scope or just the mirrors?
5) Have you ever made a mirror? Was it worth it?

Thanks for anything you can tell me.


As a SCT is a closed telescope, I suspect you would have to return it to the manufacturer, or else find someone that specifically deals with them.

However, because it is closed, unless something awful happens, you shouldn't have to get the mirrors resurfaced or recoated.

My experience is more with Newtonians, although I have friends in our club with SCT's and I've seen lots of them at star parties.

For a Newt, you remove the mirror and send it to a company that coats them. For a SCT, I wouldn't want to open it up.

Making a mirror is something to do if you enjoy that sort of thing, or if you really want to work hard to get a really good mirror. It's not something you would do to save money, as you would make far less per hour than you would make flipping burgers.

ljbrs
2002-Jan-05, 08:53 PM
Folks:

Secretly, I have always wanted to find the time to grind a mirror which would make images worthy of the Museum of Modern Art (NYC) or the Guggenheim (NYC) rather than for any other purpose. I could use it at star parties to startle unexpecting viewers who would gasp (in pain) at the weird sights they would encounter through my *engineered* silly-imaging scope. I am somebody who thought that the first Hubble Space Telescope image was gorgeous (of course, from an artistic point of view and never from an astronomical point of view). Then again, it would not be human *art* unless it were *created* by a human being rather than *produced* by a machine. However, on the other hand, if an artist could control the production of the scope/machine (such as the Hubble) to make images completely as artifacts of his/her designation, then that would be another thing. To tell the truth, perfection and purity often do not *make it* in the present-day artsy-smartsy crowd.

ljbrs /phpBB/images/smiles/icon_smile.gif /phpBB/images/smiles/icon_biggrin.gif /phpBB/images/smiles/icon_eek.gif

_________________
*Nothing is more damaging to a new truth than an old error.* Goethe

<font size=-1>[ This Message was edited by: ljbrs on 2002-01-05 15:55 ]</font>

Donnie B.
2002-Jan-06, 10:17 PM
Heheheh... I like it...

"My telescope has a 10" funhouse mirror!"