Really Big Dob Project Anyone?

[SnakeyJ]

Anyone minded to build a really big (34" F4) dob?

http://astrobuysell.com/uk/propview.php?view=96845

[gooseholla]

Do Telescope House sell mirrors, or is it really old?

I think after building an 18", that is big enough for me!

John



 

[SnakeyJ]

Do Telescope House sell mirrors, or is it really old?

I think after building an 18", that is big enough for me!

John

They did back in the 70s and 80s.   Origionally it was Broadhurst and Clarkson, but was brought out by Dudley Fuller or Fullerscopes fame (or infamy ).    It's possible this could be a Henry Wildey mirror of that vintage, or perhaps a newer one brought via Telescope House more recently.    Sure that someone here will know the provenance of this as there can't be many of this size in circulation!

[Beulah]

Three-and-a-half metre focal length? Planning permission would be needed to build the obs... 

[SnakeyJ]

Three-and-a-half metre focal length? Planning permission would be needed to build the obs... 

Nothing a step ladder and large trailer couldn't handle!

Thinking about this over supper, £5K does not sound terribly expensive for such a big mirror!

[Beulah]

Yes, I agree on the relatively low price -  it's do-able, if you have a few squid in the bank, or arrange a loan.

Hi-Luxing it (recoat) will most likely cost a fortune...

Both are nowhere near possible but one can dream... 

[gooseholla]

Didn't it say it had been recoated recently? Does it come with a secondary, or are we just going to hang a 10" mirror down the tube

That would be a beast if you had a large observatory or field in the middle of nowhere and could leave it assembled and observe in comfort. Not sure I'd want to be up and down ladders all night or set it up/take it down. Perhaps it is too much mirror for one man and a group or society need to take the project on?

John

 

[Ajohn]

 Oldham optical will do you a 30in for £"Ask" maybe he would undercut the astrobuy sell price which to me sounds too expensive plus the need for a 1 tonne trailer. If it's an older mirror it might be 5in thick at least and I suspect it wouldn't be far off that if a recent mirror as well.  Hope some one on here buys it and posts. I'd love to see how they got on with the mirror cell and tube.

Telescope House - probably sell anything if there is money in it. No mirror blank kits any more though. Sad that. The pre grinding was brilliant, tool too which wouldn't be needed these days.

John

-

[Peter Drew]

If it's an old mirror it could be by Basset & Gowen, there were a couple around about that size in the late 60's.

[Merlin]

Norwich Astronomical Society had a 30" reflector, but has since down-sized. Which UK astro society has the biggest 'scope these days?

[keithatrochdale]

There is a 30" just being commissioned at 

http://www.astronomycentre.org.uk/

Just looking for a good large step ladder!

[Ajohn]

Sounds like they are planning a 42in as well but have problems with a wind farm being built around them. Wind farms - I wonder how much subsidy they get. As I see more and more of them they are beginning to give me the same feeling as over lit streets do.

John

-

[gooseholla]

I can't stand wind farms. They are a blight on the countryside. You look out down towards Bradwell from here all you see is a horizon of the ghastly things. The same is true of where my family grew up in Norfolk. It is a shame they may have to scrap a telescope so large because of the horrible things.