Grind your own?

[erick (Eric)]

Seriously, I'm interested in why an amateur would choose to grind their own primary reflector mirror?

Possible reasons??:-

1. Cheaper than buying a finished mirror

2. Better than any finished mirror I could buy

3. I needed a unique size and/or focal length

4. Because I could

5. Because I wanted to make everything
in my scope

6. I have a lot of spare time on my hands

7. The challenge! (The Mt Everest answer)


Dare I ask about people making their own refractor lenses? Eyepieces? !!

[Orion]

Have you thought about..... 8. because it is enjoyable?

[erick (Eric)]

No I didn't, because I couldn't see how it would be! . Whenever I have to file off some wood or metal for half an hour, I lose all interest after about five minutes! Woops! I think I've pre-judged.

[AstroJunk (Jonathan)]

Today I wouldn't for the same reason that I wouldn't build any other part of a telescope - because I can spend less money getting someone else to do a better job.

25 years ago I ground mirrors because I simply couldn't afford aperture in any other way. How things have changed.

Some people actually like grinding mirrors and find it relaxing. It can be, but for the most part I found it very very dull. The figuring part at the end is good, as it demands some thought and skill, but the rest is best left to a machine!

And maybe I lack romance, because I never got a millisecond more pleasure from the view through a telescope that I had spent hundreds of hours building than an equivalent shop bought one. The opposite in fact, because I am much more tolerant of flaws in other peoples workmanship than I am in my own!

[ving (David)]

dang, i thought this was a thread about coffee...

grinding... nah i dont have the patience for it. each to thier own tho huh

[erick (Eric)]

Originally Posted by ving

dang, i thought this was a thread about coffee...

Speaking of which - time for a cuppa. Pre-ground is OK - as long as it it Lavazza and is vacuum packed!

I agree with you - I don't think I'd have the patience to grind a mirror or to rectify a mistake I made when the job was mostly done!

[Starkler (Geoff)]

Originally Posted by Orion

Have you thought about..... 8. because it is enjoyable?

Or 9...."Im a masochist" ?

I think 3 or 7 would be the most likely motivators. I doubt many glass pushers unless very experienced can equal the quality of the best commercial makers.

[Rod]

I think when I started in ATM, Cost was the answer. Now I do it partly because I can and because I do get a kick out of looking through something I made myself. In the future I think Iwill make my own because I can experiment with designs that are either hard to get or expensive (eg. cassegrains, TCTs).

Rod.

[Orion]

It surely is satisfying looking through a telescope that has been built by ones own hands.
Glass pushing is not for every one patience, determination, perseverance are some of the qualities that are needed for this type of thing.

This site is one of many on making mirrors, so there must be something enjoyable about it.http://stellafane.org/tm/index.html

[Garyh]

Making only one mirror so far I found great satifaction in knowing that I made a precision optical surface with my own hands.
You have control over all aspects like your focal length and when to stop figuring as to how accurate you are happy with like a 1/4 wave or a 1/20 wave mirror.
I was happy to get around a 1/10 mirror.
You might save some money if you are planning on a big premium mirror but little mirrors I think its cheaper to buy one.
The grinding bit is a bit tedious but is great to do when its raining and the kids are in bed while you listen to the radio!
Will be doing a 8" next year the a 10" after that.
I should be getting the hang of it by then!!
cheers Gary

[skies2clear]

Originally Posted by erick

Seriously, I'm interested in why an amateur would choose to grind their own primary reflector mirror?

For the same reason(s) some people choose to make their own furniture, or do anything else that inspires them, compared with those that employ the services of someone else.

For me, I'd say...

The joy, satisfaction and pride doing it yourself.

The hope you will meet or exceed the desired design objectives.

The knowledge gained from the experience can help in having a clear understanding of how your telescope works and assist in optimising it's performance.

The fascination that with such basic tools/materials, you can fashion an optical surface accurate to fractions of a wavelength of light.

The question in some peoples minds that arises could be, how much effort was put into the figuring of a mirror I intend to buy? By doing it yourself, assuming you have at least good basic skills in doing things with your hands (some people just don't!), you have control over the final result depending on how much effort you are willing to put in.

Years ago, it was definitely less expensive to DIY, but nowadays, compared with the cost of massed produced optics, the advantage isn't as great. Still cheaper than premium optics though, and with experience, you can make a very nice mirror.

But for different folks attempting this, no doubt the reasons vary somewhat.

Clear skies