Trying to source a mirror?

[Daniel-K]

having been in "work" on overtime last night i found myself searching for optical suppliers in the uk. ive come across a few company's that use the BK7 substrate for the company which manufacture high quality optical goods. my queastion is would these company's )although may not understand) but could they produce a mirror to a greater quality with finer tolerances? i know its good to give our money to the astronomy company's but surely if there's a company whos working with these fine tolerances, wouldn't it be worth asking them?

Dan

[ronin]

If they have the equipment to grind a parabolic mirror then they likely can produce a very good one.

However it will be a one off or specialist manufacture and you will pay a lot for it.

The other factor is that because the glass is simply a shape and support for the reflective coating you do not need a good quality glass. Basically ano old bit with no bubbles or cracks in will do.

Someone made the hubble mirrors to whatever tolerance and they were not Synta or Orion so yes an optical company can produce high accuracy mirrors, however I fear the cost. When you make your own mirror the time is not figured into the cost, but say 4 weeks at £50 per hour (what an optical manufacturer will charge) and you start to get an idea.

[Daniel-K]

If they have the equipment to grind a parabolic mirror then they likely can produce a very good one.

However it will be a one off or specialist manufacture and you will pay a lot for it.

The other factor is that because the glass is simply a shape and support for the reflective coating you do not need a good quality glass. Basically ano old bit with no bubbles or cracks in will do.

Someone made the hubble mirrors to whatever tolerance and they were not Synta or Orion so yes an optical company can produce high accuracy mirrors, however I fear the cost. When you make your own mirror the time is not figured into the cost, but say 4 weeks at £50 per hour (what an optical manufacturer will charge) and you start to get an idea.

Hi Ronin ive started emailing some company's anyway, be interesting to see what they come back with who knows i may get lucky and they may have some 18" blanks laying about

[faulksy]

all the money your on, just buy a obsession

[Daniel-K]

all the money your on, just buy a obsession

i should really shouldn't i lol if i worked for a month and didnt pay any bills or feed the wife and kids i could get the 20" UC

[faulksy]

i should really shouldn't i lol if i worked for a month and didnt pay any bills or feed the wife and kids i could get the 20" UC

just to be fair to the family spread it over 2 months, they can eat eggs and veg then you can get your 20" ultra everyones happy, they will understand

[crashtestdummy]

The only company in the UK that you will get any glass from is spectraglass.I spent over a month looking for a supplier and they were the only one who supplied borosilcate glass above 12".

[estwing]

Pilkingtons!!

[crashtestdummy]

You struggle to get anything above 25mm unless it's safety glass.

[Daniel-K]

The only company in the UK that you will get any glass from is spectraglass.I spent over a month looking for a supplier and they were the only one who supplied borosilcate glass above 12".

how much did they charge you for your blank?

[crashtestdummy]

I paid just under £500 for a 22" blank but I got 5% discount for buying two.I have prices somewhere for 20" and 18", will dig then and my contact out for you if you are interested

[Daniel-K]

I paid just under £500 for a 22" blank but I got 5% discount for buying two.I have prices somewhere for 20" and 18", will dig then and my contact out for you if you are interested

yeah please. did you ask them for a price on a finished mirror?

[crashtestdummy]

No they are just suppliers.tbh I wouldn't trust anyone except a mirror maker to do it.

[crashtestdummy]

Info@spectraglass.com

18"x40mm £352

20"x40mm £378

22'x40mm £406

Prices plus vat and £18 carriage 2-6 weeks for delivery.

Prices may differ now as I ordered mine in December.

They are a bit slow answering emails but you will have to be patient as they are pretty much the only UK supplier that will deal with individuals

[Daniel-K]

Info@spectraglass.com

18"x40mm £352

20"x40mm £378

22'x40mm £406

Prices plus vat and £18 carriage 2-6 weeks for delivery.

Prices may differ now as I ordered mine in December.

They are a bit slow answering emails but you will have to be patient as they are pretty much the only UK supplier that will deal with individuals

yeah they do differ ALOT! £480 for a 18" blank    £1200 figured though

[crashtestdummy]

£480 for an 18" from spectraglass???

[Daniel-K]

Yes

[Rustysplit]

I think they have misunderstood you somewhere Dan, this is what they told me a few weeks back....

They are borosilicate low expansion as per your request

18” Dia x 25mm Thick    £260.00

18” Dia x 30mm Thick   £286.00

18” Dia x 35mm Thick    £301.00

18” Dia x 40mm Thick  £330.00

18” Dia x 45mm Thick  £370.00

18” Dia x 60mm thick £400.00

Carriage charge will be £25 as we send these on a pallet

Delivery 3-4 weeks from date of order and we would ask for payment in advance against pro forma invoice

Oh, and no, I am not embarking on another grind, just finding prices out .......

Are you sure 18" is gonna be a big enough step up from the 14"? I thought you needed to add 50% to see a noticeable improvement

[Daniel-K]

I think they have misunderstood you somewhere Dan, this is what they told me a few weeks back....

They are borosilicate low expansion as per your request

18” Dia x 25mm Thick    £260.00

18” Dia x 30mm Thick   £286.00

18” Dia x 35mm Thick    £301.00

18” Dia x 40mm Thick  £330.00

18” Dia x 45mm Thick  £370.00

18” Dia x 60mm thick £400.00

Carriage charge will be £25 as we send these on a pallet

Delivery 3-4 weeks from date of order and we would ask for payment in advance against pro forma invoice

Oh, and no, I am not embarking on another grind, just finding prices out .......

Are you sure 18" is gonna be a big enough step up from the 14"? I thought you needed to add 50% to see a noticeable improvement

50% Mrs K would kill me!

[crashtestdummy]

Assuming those prices are plus vat?do a 20",18" is so last year