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The Questar 12

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#1 astro_que

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Posted 22 April 2010 - 03:27 PM

At NEAF, the owner of the company spontaneously expressed his desire to build new 12"'s, with the same thermal innovations as the Titanium 7.

#2 Steve C.

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Posted 22 April 2010 - 04:07 PM

Gawd, what would something like that cost?

They would definitely need some new engineering for equalization.

#3 greedyshark

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Posted 22 April 2010 - 04:17 PM

They would definitely need some new engineering for equalization.


...and I would definately need another source of income to afford. :scratchhead:

CS,
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#4 astro_que

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Posted 22 April 2010 - 05:01 PM

They now believe they have the thermal technology to build any size Mak. It just takes a lot of titanium and fancy machining.

#5 ColoHank

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Posted 22 April 2010 - 10:52 PM

It takes a big, thick hunk of glass and a lot of grinding to produce the deeply curved corrector for a 12-inch Mak. Hang on to your wallets!

#6 JohnH

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Posted 09 May 2010 - 11:05 PM

As an owner of an original 11 1/4" Hayward BSC-2 glass blank made in the late 50's, I can testify that the obstacles to overcome require a bit more than titanium. Even back then, this piece of glass was some $300, which could have bought a good used car then.

The front corrector on the 12 is some 1 1/2" thick, with deep curves. The only ways to make one is to start with a solid piece of optical glass and generate the deep curves on both sides or slump mold a suitable piece and then anneal it. The latter has the problem of rejects due to a poor anneal, resulting is a high percentage of loss. The former requires a glass blank that is around 2 1/2" by 13" in diameter.

Having looked through one on several different nights, I can also attest to the need for thermal reconciliation to get the best use of one.

This size pushes the limits of practicality on the design. My own design using the 11 1/4" corrector blank suggests the lower limit of weight is around 45 lbs, assuming an aluminum tube machined down, an open cell to reduce weight and to help cool the mirror.

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#7 saemark30

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Posted 27 April 2012 - 02:17 PM

Anything more about this Q12?
I sure like to see something like like, even ATM made.

#8 Steve's 50th

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Posted 28 April 2012 - 09:51 AM

I would think that the demand for a Q-12 would be very limited, to the point where it is not practical for Questar to attempt to make them. If I remember correctly, back when they tried to promote them they sold less than a dozen? I think there are just too many other designs that can produce the same results at a far lower cost. I'd love to own one but will never be able to due to the cost.

#9 GeneT

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Posted 12 June 2012 - 06:51 PM

It takes a big, thick hunk of glass and a lot of grinding to produce the deeply curved corrector for a 12-inch Mak. Hang on to your wallets!


It would also be quite heavy.

#10 Billydee

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Posted 12 June 2012 - 08:45 PM

I think that they are developing one for a government contract. I would expect it to be in the $250,000 to $500,000 range.

Bill

#11 Erik Bakker

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Posted 13 June 2012 - 02:20 AM

I think that they are developing one for a government contract. I would expect it to be in the $250,000 to $500,000 range.

Bill


In that case, I'd start searching for an A-P 10" Mak or have Matthias Wirth build a 12" MCT for you. Nostalgia apart, you would end up with a more enjoyable and of course affordable scope.

#12 Bill Boublitz

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Posted 12 May 2013 - 10:55 AM

For a time Company 7 had listed the 12" as under development. It's since been removed.

During one visit to the Questar facility, I asked Jim Richert about the 12". He said they were slowly working it out. Since their primary income source are government contracts, they only fool with it when they have time. Of the prototypes, he stated they have more work to reduce weight and cost but added, "I could sell forty of these right now, sight unseen. We'll get there."

Makes you wonder, doesn't it?

#13 dawziecat

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Posted 25 May 2013 - 01:13 PM

If I remember correctly, back when they tried to promote them they sold less than a dozen?


Less than a dozen? Wow!
I saw one, "in the flesh," so to speak. Was driving through New Hope, quite by accident and stopped when I saw the Questar buildings. There was a yellow 12" OTA just lying on the carpet. The year? About 1981.

#14 Michael Lomb

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Posted 26 May 2013 - 10:36 PM

In case anyone is interested, here is a post from another site from someone who had observing time with a Questar 12 and wrote up about his experience.

http://adsabs.harvar...JRASC..80L..15M

#15 Bob Myler

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Posted 27 May 2013 - 08:39 AM

It appears that they didn't have much to say...

#16 mdowns

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Posted 27 May 2013 - 02:16 PM

Actually he did. You need to advance to the next page.

#17 Bob Myler

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Posted 27 May 2013 - 09:43 PM

Ooops! My bad. :tonofbricks:

Thanks.

#18 JohnH

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Posted 01 June 2013 - 09:44 AM

The Q12 to my knowledge they made 16 or so of these, all on a massive GEM made by Edward Byers, who's name in gear making is legend.

#19 Starhawk

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Posted 03 June 2013 - 12:54 PM

The thermal management is a good question for this. I'd imagine at that price point you might assume the observer would have a dry nitrogen purge available.

-Rich

#20 orion61

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Posted 03 June 2013 - 08:31 PM

I want a Space Shuttle too ..but..
That is just too big to be practical.
I would say 9 or 10" would be more like it.
Apples and Oranges, but I saw detail through a 12" Cave Astrola with reported 10th wave optics I never would have believed possible, it made another members C11 look like "viewing through a dirty window" Simply amazing.
I'd sure love a chance at a Moonless night with Mars at Opposition and Uranus visable. I am one of those guys who seriously study the outer Twins, With ex optics and outstanding seeing conditions there are details to see.
I have 20/15 +2 vision so I was lucky in that department.
Has there been a decision of the 12" Color scheme?
will it be the Yellow prototype I saw?
I'm betting only sub 1% of us in population would spend the money for that instead of other things..
You would need to put it in your Will.

#21 ColoHank

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Posted 03 June 2013 - 11:45 PM

Not sure the Q12 is exactly a prototype. I recall reading somewhere or another that NASA has been using one for years to film launches at Cape Canaveral.

#22 mckay3d

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Posted 09 July 2013 - 06:32 PM

Here is a picture of a Questar 12 from the late 1970's.
Taken at the RTMC in California.
Maurice

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#23 Littlegreenman

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Posted 09 July 2013 - 07:19 PM

Is that on a Byers mount?

Edit: I went back and read the whole thread; JohnH above stated they were sold on a Byers mount.

LGM

Green with envy~! (I can't even afford the mount!)






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