Argo Navis equipped 48" Dobsonian nears completion

[gary]

A buddy in Texas, Jimi L., recently forwarded me some images of his new
48" f/4 Dobsonian that is nearing completion. I have attached these images here.

The gentleman in front of the telescope is James Mulherin, President and
Lead Optician at Optical Mechanics. Inc (OMI) in Iowa. The pictures were
taken in the OMI workshop where the telescope was constructed.

The primary mirror itself was supplied by Yuri Petrunin at the Telescope Engineering
Company in Russia.

The telescope is fitted with a ServoCAT and one of our own Argo Navis
Digital Telescope Computers (http://www.wildcard-innovations.com.au) for full slew/track and pointing capability.

OMI have a web page devoted to the scope and you can read about it here.
http://www.opticalmechanics.com/48Dob/index.html

Once complete, the scope will be moved to Jimi's new custom home observatory at
a dark sky site at Limpia Crossing in Texas, only a few miles away from where
the Texas Star Party is held and close to the McDonald Observatory.

The telescope took a remarkably short amount of time to construct. Jimi talked
excitedly about it less than a year ago when we were at the Texas Star Party
and then at RTMC near Los Angeles afterwards. James Mullherin
agreed that OMI would take on the task of building it and with first light now
having been achieved and delivery expected in April, it is a remarkable
achievement.

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

[iceman]

Holy cow, that is a monster! Incredible!

You must be very proud and excited, Gary. A scope like that is gonna get a lot of attention.

Will you get to have a look through it?

[gaa_ian]

OMG :eyepop: that is one mother of a telescope !
Thats the kind of scope you build an observatory around and people have to book research time on it.
Naturally enough it is going to Texas ;)
From what I have seen of the Servocat and Argo Navis on 24" scopes it will be a match made in heaven.

[h0ughy]

geez you'd get nosebleeds just getting up there to view the eyepiece…….

Man you would certainly know how turbulent the sky was when looking through that!!

[Miaplacidus]

Excuse me, Gary, but just say I had two of these telescopes, right, with a view to turn them into binoculars, right, and two servocat thingo systems to drive them, let's say... well, could I get by with only one Argo Navis, or would I need two of those as well?

Looking forward in anticipation to your considered response,

Brian.

[g__day]

How did you break your leg? I fell of my telescope...

[erick]

How did you break your leg and your mirror......I fell into my scope!

[Kokatha man]

I'm sure that fella ain't gunna have any problems skwinting through the ep's. Why, he'll just have the latest cherry-picker customized with a fully-automated, recliner-like armchair up top (ergonomic seat harness of course) in colour-coordinated, full-thickness leather..........

That is, of course, when he's not slumming it with the (also custom-built) ultra-high definition super-wide screen monitor; viewed sitting in his ground-based, full-thickness, colour-coordinated leather..........

[gary]

Hi Brian,

Thanks for your question. Let me put it this way. We certainly wouldn't
fool you into buying any more than what you need. ;)

Best Regards

Gary

[gary]

Hi Brian,

On a more serious note, with regards the ServoCAT drive system, which Argo
Navis performs the drive rate calculations for, the 48" scope is equipped with
relatively modest 23mm servo motors which are then geared 10.6K:1 to provide
slew speeds of over 5 degrees/sec.

The primary mirror alone of the 48" weighs around 317kg.

Gary Myers of StellarCAT, the manufacturer of the ServoCAT, reports to me
with a slightly higher gear ratio, one might be able to move about a ton
(approx 907kg) and still slew at a respectable 4.2 degrees/second.

Therefore, on a hypothetical larger scope such as a giant binocular scope
weighing in around a ton, one could probably get away with a single
ServoCAT drive system.

Archimedes was quoted as saying that "give me a large enough lever
and I can move the world". This is the mechanical advantage that gearing
provides. If you ever get a chance to see the radio telescope at Parkes up
close, it is revealing as to how small the motors are that manage to move such
as massive thing. Again, the gear box provides the magic. :)

Thanks again for the post. :)

Best Regards

Gary Kopff
Wildcard Innovations Pty Ltd

[gary]

Hi Mike,

It certainly is a dream telescope, isn't it?

Indeed, we are proud and excited and I am sure many IceInSpace readers
are likewise proud to see Australian designed and manufactured astronomical
product being deployed in this way.

Having said that, we are also well accustomed by now to seeing Argo Navis
being deployed as the telescope computer of choice on premium telescopes
or on more modest telescopes where the owner simply wanted the best.
For example, it is not uncommon to see Argo Navis used on tiny refractors
or on 8" Newtonians.

The largest aperture scope I am aware of that has an Argo Navis deployment
is the 72" David Dunlap Observatory in Toronto.

As you are aware, a small circle of Australian observing friends have made close
ties with brother and sister observers in North America. In particular, we now
have many good friends in places such as Texas. Many of them have taken
the opportunity to come and observe with us in Australia and likewise we have
responded to their invitations to observe with them in Texas and elsewhere in North
America. In that regard, Jimi has graciously extended myself and colleagues a
standing invitation to come and bring our observing lists and use the 48" next time
we get to Texas. That's an invitation one can't refuse!

Thanks again Mike.

Best regards

Gary

[wavelandscott]

Wow, that is a seriously large scope. I think it is cool that they are using an Argo Navis as "the brains"...Way to go Wildcard Innovations!

[sheeny]

Wow! Great to see! Thanks for posting, Gary!

My first thought when I saw it was "fall protection":lol:... such is life in today's industry:rolleyes::whistle:.

Al.

[AstralTraveller]

So what would you use for an eyepiece if you want an even moderately wide field of view? If it a 120cm f/4 that is 480cm focal length. Even a 50mm plossl will give a true fov of <0.5 degree. Are there monster eyepieces out there to suit monster scopes?

This pure for academic interest. Certainly of no practical use for me - I'm afraid of heights :P.

[norm]

:scared: Imagine sewing the shroud for that !!! and collimating it !!!:P:lol:

[citivolus]

It makes me wonder what magnitude of star could cause permanent retinal damage. Certainly you wouldn't want to try splitting Sirius with it?

[sejanus]

by gosh that makes my lightbridge look like an 80mm

[gary]

16" is a nice aperture. But then when you consider the 48" has 9.3-times more
light gathering surface area, it really is an eye-opening prospect!

It certainly would make looking for targets such as extragalactic globulars all
that little bit easier.

Best regards

Gary

[janoskiss]

48" for visual is a bit nuts when you consider that the lowest magnification where the average human eye can make use of the full aperture is around 200x! But hey, if I had the chance to look through it, I'd step over my mother to do so! :lol:

[CoombellKid]

If that bloke had my lil 8" truss dob standing next to his right arm pointing
straight up, he could rest his elbow on it.

What a scope!!!!

regards,CS

[gary]

Hi Steve,

In Texas last year we were lucky enough to be looking at M51 through Larry Mitchell's 36".
How could I best describe it? Sure, I've seen lots of mind-boggling great
astrophotographs, including right here on IceInSpace, but no photograph could
compare with that stunning view in real-time with your own eye. It's a bit like
the difference between looking at the postcards of some place and actually being
there and seeing it for yourself. I joked to Larry that I didn't think the amazing view
really had anything to do with aperture, it is simply because by the time you have
climbed to the top of the ladder on these monster scopes, you are just that
much closer to whatever you are looking at. ;)

M51 is about 11.2' x 6.9' so it would still probably make a great target in 48".

One thing that is commonplace with American observers is the use of step ladders
with half-steps. In other words, the steps are spaced at half the normal distance,
so there are twice as many of them for any given length ladder. These types
of half-step ladders make the climb up and down just that little bit more
reassuring, but I note they aren't common on observing fields in Australia.

Anyway, hope you get the chance to look through some serious aperture
without having to trample over family members for the opportunity.

Best Regards

Gary

[Brian W]

Gary thank you for saving my marriage by killing my aperture fever. the potential for the monster is incredible. this is such a tacky question but i am curious in an academic sort of way, in round numbers what is the cost?
Brian

[coldspace]

Gary,

Just for curiosity sake if you know, what would the estimated limmiting Magnitude be for a scope this size. I know Peter's 30 inch is around 17.5 visually but this sucker must be at least another 1 to 2 magnitudes more. The 30 inch has some mind blowing views through it and is the biggest dob I have looked through but this thing has over 2.5 X the light collecting area:eyepop::jawdrop:of the 30 inch.

Matt.

[CoombellKid]

This wouldn't happen to be Peter Robbins 30"? it has a spectacular mirror
in it and is the largst visual scope I have looked through too.... awesome!!!

regards,CS

[coldspace]

Yep, its Peter Robbins 30 inch, when you look at eta carina through it you loose your night vision for a few moments then its hard to climb down that ladder because you are dazzled:rofl:.

Matt.

[Stephen65]

Just to nitpick, while Yuri is of Russian heritage TEC is an American company based IIRC in Colorado. They are better known for making APO refractors but it seems Yuri also does custom mirror jobs.

[gary]

Hi Matt,

With the right conditions, possibly 19th mag or better.

Jimi lives at a good dark sky site in the south-west of Texas, only a few miles away
from the 9.2m segmented mirror Hobby-Eberly Telescope, so it will be sited
at a good location.

Indeed, Peter's 30" f/4.8" SDM is a wonderful scope to look through ... and look at!

Best Regards

Gary

[gary]

Hi Brian!

Mabuhai!

You are welcome. :)

I don't believe the price has been publicly released and it would be really up to Jimi
if he wanted the figure to be known. Suffice to say, it is not cheap.

Combined with a new house and custom designed observatory being built on a new
parcel of land, along with accessories such as a scissor-lift for the observer to ride in,
it is a substantial investment into a life-style that for many observing enthusiasts
would be like a dream come true.

Rest assured the owner is just as excited as we would be and this scope will
be well used and well loved.

Best Regards

Gary

[GrahamL]

The aluminium plate just for those side bearings is more cash than I care to think of...so the glass for these big scopes has to be a made to order ? you'd nearlly have to be heading up towards 100 without to much trouble .

So who wants to throw in and we'll get one :)

[abellhunter]

Hey Astro Heads!

That's enough scope for me! http://www.opticalmechanics.com/
What a fine job OM has done! You know this thingz going to be
hard too top!

Aloha Lance aka "abellhunter"

http://www.anzaobservatory.com

...is Moving to the Southern Hemisphere any ideas, suggestions or
comments?
humphreys@greencafe.com

___________________________________ ___

p.s. Regarding "nightstalker" ; "So who wants to throw in and we'll get one :)"

See:

Large Group Scope &/or The new OZ Observatory plan [see post #35]
http://www.iceinspace.com.au/forum/showthread.php?t=27969

and:

As some of you know allready i am looking to build
an observatory and move the ARSENAL down under!
See post #354
http://www.iceinspace.com.au/forum/showthread.php?t=65


Looking for a new project!

abellhunter