That's a lot of glass!

[erick]

Anyone want a big mirror?

http://www.loptics.com/shop5.html

http://www.loptics.com/shop7.html

[Kal]

I always consider the ladder to be the sign of large aperture. But when a forklift becomes the required accessory...:eyepop:

[multiweb]

Wow! How would you polish and figure something that big?

[jenchris]

Lots of Mr Sheen?
See, I figured that out real quick!

[ballaratdragons]

Definitely not your average 'Grab-N-Go' scope :P

[snowyskiesau]

I wonder how much dust he gets off those corn fields?

[mental4astro]

Pollen, mate, pollen will settle on the thing.

Then bacteria will chow down on the stuff. Their acidic waste will then eat into the coating of the mirror and in not time at all will render the thing completely useless, Ha ha ha ha!!!! (laughed in a deep, demented tone)

:evil2: :evil: :fight: :wink2:

[mozzie]

thats one nice piece of glass!!!!

[robz]

According to the Refractor forum on C.N., an ED80 will match it quite easily :P

[jenchris]

Match it for what?
The only thing I can see matching it is the fact it is measured in mm

[robz]

C'mon Jenny...................''refractor itis'' is known to cause delusions of grandeur................that's why it will match it in optical performance:D..............just look at how BIG that central obstruction will be........robbing the image of fine details and contrast:lol:

Seriously though, what a mirror!!!:eyepop:

[Satchmo]

Professional optical workshops geared up for this size generally use polishing machines whose mirrors do not need to be manhandled on and off the machine into another stand for testing , but stay in -situ with a tilt down turntable for testing and not under threat of damage every time they are moved.

I would be a little nervous over all the maneuvering given a mirror this size will have to be tested 100's of time during polishing and figuring ... Its quite a task thats been taken on there.

[erick]

So it will be interesting to see how Mike L goes with this one - he has locked himself into reporting progress it would seem.

[jenchris]

Robz my dear boy, if I was serious, my avatar would have a frown.
I know the rivalry that goes on with Tasco refractor owners - or those that wished they owned a Tasco....
It IS a Tasco you have isn't it? :D

Actually I'm a mirror person. If anyone thinks they can see better looking THROUGH a piece of glass than a reflection off it, then they're delusional.
I wouldn't have bought an SCT, would I? if it were not true...:rolleyes:

Now, I'd like to think that there'll be silence from WA for a while.........
Bet there isn't though;):astron:

[OICURMT]

http://group70.org/

[erick]

One that got away!!

"The mirror of the 71" telescope is now complete. The mirror blank, found at the University of Tasmania, Australia, is made of Pyrex glass and was originally cast in 1938 as a backup blank for the 48" Schmidt Camera now in service at Mt. Palomar Observatory."

20+ years on and still coming. Wikipedia reports:-

"Group 70 is a non-profit (http://www.iceinspace.com.au/wiki/Non-profit) educational (http://www.iceinspace.com.au/wiki/Education) organization of people from many countries all around the world and many walks of life seeking to make astronomy (http://www.iceinspace.com.au/wiki/Astronomy) available to the peoples of the world. They began in 1988 with the goal of building a large amateur telescope (http://www.iceinspace.com.au/wiki/Amateur_telescope_making), a 70 inches (1,800 mm) astronomical instrument (http://www.iceinspace.com.au/wiki/Optical_telescope). Upon completion it would be the largest telescope in the world built by and for amateur astronomers. Beyond building a large aperture telescope, they offer related instrumentation and services to those in amateur, professional and educational fields of astronomy.
As of mid-2008, the project has moved from San Jose, CA to Fremont CA and work has moved from the mirror to the steel and other optics.
Use of a comparable telescope in California is very expensive: a rental must be scheduled well in advance and the weather may not cooperate."

[skies2clear]

He won't be starting with 80 grit....more like a hammer and chisel!

[robz]

Jenny, I also own an 8 inch reflector by the way, and was only having fun.

Silence from W.A?...................you're dreaming:D

[jenchris]

and was only having fun.
I know.....
I'm a tease....
Your Sheffield Shield team had better beat Qld or you'll never hear the last of it

[robz]

he, he, he.............:)