48"...

[Orion]

Imagine the size of the ladder to look through this thing!

http://www.opticalmechanics.com/48Dob/index.html

[gman]

man that is one huge scope.
put it beside my house and I would need to be on the roof to look through the eye piece
Cracker of a post Ed.
Cant wait to see it installed

[h0ughy]

now - just to get George to finish his project Eh Ed?

[shane shaw]

Now thats a nice scope. Would be a waste in the city, but what a scope to have in the dark skys. You need a seperate trailer for the thing

[GrahamL]

Planning your next one already Ed ?:)

[Ian Robinson]

George Levanis (in Newcastle) was thinking of doing one several years ago (using a pre-sagged ultrathin blank).

Not sure if he ever got that project going , as he was still tinkering with his 32" dob with an ultra thin mirror , I think he had issues with his mirror flotation at the time.

I think a dob or newt that big warrants folded optics with a big seconday and a tertiary (diagonal) mirror , or a cassegrain optical configuration , to bring the focus to a level that is easily accessible w/out a ladder , or going to a fulltime prime focus CCD imaging arrangement , doing away with a focusor entirely.

Try Newport Glassworks in the USA for your blank if you go ahead, they'll do fine and precision annealed blanks , and preradiused blanks , and sagged blanks most any size up to about 50" I hear.

[Ian Robinson]

Is that George Levanis (in Newcastle) you refer too ?

[Orion]

No!....But if I were to build something that big it will have to be a Nasmyth.

He has already built the telescope and is finishing the optics.
Details...48"f8 folded Herschelian telescope.
1.2m octagon aluminium primary mirror,
600mm aluminium secondary
and a 7" (178mm) tertiary.

Yes.

[bojan]

Without permanent site, this project is a waste of time and money, IMO.

[Ian Robinson]

Wow !

Is the focal path passed to a cavity through one of the altitude bearings or is he going to build a big fork equatorial mount for it ?

[Ian Robinson]

Not necessarily , the ASH has / had last time I heard a dark site on a properly near Kurri Kurri .

A big scope on a souped up / modified trailor is a great solution too , you can simply tow it to a dark location and a few minutes of tweeking the collimation and leveling (and polar alignment if equatorially mounted) and you are in business , you don't have to buy a block of land or develop an observing site .

George (if he still lives in Hamilton, an inner suburb of Newcastle) doesn't need to travel far home to get to a good observing site where the sky is dark and clean(pretty dark north of Raymond Terrace, or west towards Kurri , or south towards Rathmines).

Been several years since I touched base with George, I should look him up sometime.

[GrahamL]

I believe this scopes owner is retireing and going to live high in the mountains with an observatory and home built around it .

but will he truly be happy ?:shrug: ..I'm going with yes :thumbsup:

[Ian Robinson]

I am green with envy ....

If he plays his cards right , the scope could become a tidy money spinner for him too , least wize it might become a local tourist attraction and he might get regular paying visitors who want to look through it. I wonder if that has occurred to him ?

[gary]

Hi Ed,

A scissor lift is being employed on this particular scope.

As reported, the scope is fitted with one of our Argo Navis Digital Telescope
Computers and a ServoCAT slew and track system which the Argo Navis
performs the object offset and tracking rate calculations for.

It's not the largest telescope I am aware of an Argo Navis being interfaced to,
as there is a 78" professional observatory up in Canada, but certainly the 48"
is the largest amateur scope I am aware of that uses one of our systems.

One of the most remarkable things about this scope is the incredibly short
length of time in which it was constructed. In May last year, I was present
in Fort Davis when the owner commissioned OMI to construct it. The primary
mirror itself was fabricated in Russia.

So often, one hears of dream scopes and even some modest conventional commercial
scopes, taking years to deliver. OMI have already achieved first light with the 48" and the
scope is due to be delivered shortly.

The owner is one of several friends we have in that particular corner of West Texas
and I can tell you now that Jimi is as excited as you or I would be if it were ours.
When we were at RTMC in California, whether it be chatting in our vendor's tent,
or at dinner or driving in the car, Jimi would often punctuate the conversation
with words to the effect of how he couldn't wait until he gets the 48". So we're excited
for him too.

Best Regards

Gary Kopff
Managing Director
Wildcard Innovations Pty. Ltd.
20 Kilmory Place, Mount Kuring-Gai
NSW. 2080. Australia
Phone +61-2-9457-9049
Fax +61-2-9457-9593
sales@wildcard-innovations.com.au
http://www.wildcard-innovations.com.au

[gary]

Hi Nightstalker,

Indeed, the owner will be moving the scope into a new luxury home and
observatory that is being constructed.

With the MacDonald observatory up the road at about 6,800 feet, I guess the
foot hills of Limpia Crossing are at around 5,000 feet. Down the road a few more
miles is the Prude Ranch were the Texas Star Party is held.

Since it is in the protection shadow of the MacDonald Observatory, a community
of amateur observers has popped-up around the Limpia Crossing area. Here the
Davis Mountains are really a series of rolling grassy hills on the northern part of
the Chihuahuan desert. Wildlife includes Javelnia, members of the Peccary family,
which on first glance John Bambury and I mistook for wild bore, but they are their
own class of animal. A large variety of hummingbirds can be found and they are
relatively commonplace but always exciting to watch. Some Limpia Crossing
residents spot the occasional Mountain Lion which makes for going to and
from the outdoor observatory a potentially interesting experience.

Relatively free of light pollution, far enough south that you can drive to Mexico
for lunch and a community of like minded observers makes the location that the
48" will be housed in idyllic by North American observing standards.

I can tell you now that the owner, Jimi, is as excited as we would be if the scope
were ours and he is a very avid visual observer.

At the nearby MacDonald Observatory, one can rent time on the 82" and apparently
many of the amateurs in the area have formed a group and done this from time
to time. I have been told the prices and it may have been around US$2000 per night
but one would need to check with the observatory for pricing details.

Best Regards

Gary

[Ian Robinson]

Must be nice to retire rich enough to afford such a scope.

For most of us .... just a pipe dream.

[gary]

And the real trick is to retire young enough to enjoy it if one can.

Best Regards

Gary

[GrahamL]

http://www.opticalmechanics.com/48Dob/install/index.html

I don't think I could of watched the truck chargeing that rocky old slope with my scope lashed to the back:lol:

[Starkler]

I hope the seeing is good there.

MINIMUM power viewing (6mm exit pupil) is 203x:eyepop: