I'm guessing that blank will weigh much more than 100 pounds.

The volume of the mirror is pi * r * r * h where r (radius) is 18
inches, and h (height) is 2.5 inches.  That means 2543 cubic inches of
glass or 1.47 cubic feet.  I'm just guessing the specific gravity of
glass is about 3 so we have about 275 pounds.   Of course, I am ignoring
the glass that is removed for the actual figure of the mirror but I'd
think this mirror would be well over 100 pounds.

- Bill

|
________________________________________________________________________
|
| 1. 36 Inch Mirror Blank
|     Posted by: "ghb959" ghberry@... ghb959
|     Date: Sun Dec 31, 2006 8:55 am ((PST))
|
| Hi; I am a new member that just join. And I have work out a big mirror
| blank design. The mirror blank will be of a fuse glass design. 2 1/2
| inches thick and 36 inches in diameter. The weight should be around a
| 100 pounds or less. The top glass will be slump to the F Ratio you
| want and the bottom will be flat making it easier to grind and make
| the mirror cell. I need at least four more people that would want to
| buy a mirror blank for my project to go ahead. Late summer would be
| the time to received the blanks. Thank You Gordon Berry
|

Hi Bill;
I do not have the total weight figure out but it the total mass of glass
weight less then
150 pounds I will still be happy.
I do not have a cost on the material at this time?
Everything will be made out of BVC glass. The top and bottom pieces will be
a 1/2 thick glass.
The top piece of glass will be ground flat and slump to the F Ratio.
There will be eight ribs 1 1/2 wide by 1/2 inch thick cut to the F Ratio.
The left over material will be cut and use to fill up the edge.
Then the glass will be put in a oven and fuse.
I have a 12 inch mirror out of BVC glass and it is nice to work with. It
take half the time to grind and polish then Pyrex take.
I got the ideal from looking in a old Sky and Telescope magazine. But the
one problem in fusing the glass is everything was stack and fuse and slump
with the F Ratio at the same time. Making the bottom also slump and hard to
work.
All the material use will be precut.
http://www.ajstelescopeworkshop.ca/  AJ told me he would work up a price for
me in January but I would need at least four more orders. He told me my
design would work.
He does outstanding work. The reason I went with the fuse concept was the
great savings on weight. A 32 inch 2 1/4 thick mirror blank out of BVC glass
weight around 175 pounds.
I hoped I answer most of your question this design will work and the total
weight of the scope should also come down.
This has been a goal of mine for over ten years and I filling very good
about completing it.
I am hoping that if five or more of us buy a blank that the price will come
down.
Thank You
Gordon Berry


Two each mirror blanks is a 1/2 inch thick.
Eight ribs space apart is 4.5 inches on center.
----- Original Message -----
From: "William Schwittek" <syzygy@...>
To: "MAIL LIST: Bigdob" <bigdob@yahoogroups.com>
Sent: Monday, January 01, 2007 8:46 AM
Subject: Re: [bigdob] 36 Inch Mirror Blank


> I'm guessing that blank will weigh much more than 100 pounds.
>
> The volume of the mirror is pi * r * r * h where r (radius) is 18
> inches, and h (height) is 2.5 inches.  That means 2543 cubic inches of
> glass or 1.47 cubic feet.  I'm just guessing the specific gravity of
> glass is about 3 so we have about 275 pounds.   Of course, I am ignoring
> the glass that is removed for the actual figure of the mirror but I'd
> think this mirror would be well over 100 pounds.
>
> - Bill
>
> |
> ________________________________________________________________________
> |
> | 1. 36 Inch Mirror Blank
> |     Posted by: "ghb959" ghberry@... ghb959
> |     Date: Sun Dec 31, 2006 8:55 am ((PST))
> |
> | Hi; I am a new member that just join. And I have work out a big mirror
> | blank design. The mirror blank will be of a fuse glass design. 2 1/2
> | inches thick and 36 inches in diameter. The weight should be around a
> | 100 pounds or less. The top glass will be slump to the F Ratio you
> | want and the bottom will be flat making it easier to grind and make
> | the mirror cell. I need at least four more people that would want to
> | buy a mirror blank for my project to go ahead. Late summer would be
> | the time to received the blanks. Thank You Gordon Berry
> |
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date: 12/29/2006
>
>

Some ribbed blanks that are fused together suffer from "print-through"
of the pattern into the front surface.  This may be true even if the
mirror has been fine annealed, ground and polished.  When it goes
through a temperature adjustment (as all mirrors do when used out of
doors) there may be a noticable change in the quality of the figure
that was tested under closely-controlled indoor temperature.  There is
  a backup Hubble main mirror of 97.5"x13" of zero-expansion glass that
is a sandwich of front and rear plates and a central honeycomb,
avoiding 80% of the weight of a solid disk.  It was polished and
figured at the approximate operating temperature it could experience
in the Space Telescope in orbit.  It has shown no structural problems.
Mirror structures made from a higher coefficient of expansion material
will have higher stresses on the joints than ones of more stable
glasses.  This may be true with BVC glass vs. Pyrex or Zerodur.
A 16 inch Pyrex ribbed mirror that was used in a friend's
Newtonian/Cassegrain fell apart when he lifted it out of the cell for
cleaning.  He lost 1/3 of the front part.  I think a few years of
desert hot days and cold nights did that mirror in.

--- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@...>
wrote:
>
> Hi Bill;
> I do not have the total weight figure out but it the total mass of
glass
> weight less then
> 150 pounds I will still be happy.
> I do not have a cost on the material at this time?
> Everything will be made out of BVC glass. The top and bottom pieces
will be
> a 1/2 thick glass.
> The top piece of glass will be ground flat and slump to the F Ratio.
> There will be eight ribs 1 1/2 wide by 1/2 inch thick cut to the F
Ratio.
> The left over material will be cut and use to fill up the edge.
> Then the glass will be put in a oven and fuse.
> I have a 12 inch mirror out of BVC glass and it is nice to work with. It
> take half the time to grind and polish then Pyrex take.
> I got the ideal from looking in a old Sky and Telescope magazine.
But the
> one problem in fusing the glass is everything was stack and fuse and
slump
> with the F Ratio at the same time. Making the bottom also slump and
hard to
> work.
> All the material use will be precut.
> http://www.ajstelescopeworkshop.ca/  AJ told me he would work up a
price for
> me in January but I would need at least four more orders. He told me my
> design would work.
> He does outstanding work. The reason I went with the fuse concept
was the
> great savings on weight. A 32 inch 2 1/4 thick mirror blank out of
BVC glass
> weight around 175 pounds.
> I hoped I answer most of your question this design will work and the
total
> weight of the scope should also come down.
> This has been a goal of mine for over ten years and I filling very good
> about completing it.
> I am hoping that if five or more of us buy a blank that the price
will come
> down.
> Thank You
> Gordon Berry
>
>
> Two each mirror blanks is a 1/2 inch thick.
> Eight ribs space apart is 4.5 inches on center.
> ----- Original Message -----
> From: "William Schwittek" <syzygy@...>
> To: "MAIL LIST: Bigdob" <bigdob@yahoogroups.com>
> Sent: Monday, January 01, 2007 8:46 AM
> Subject: Re: [bigdob] 36 Inch Mirror Blank
>
>
> > I'm guessing that blank will weigh much more than 100 pounds.
> >
> > The volume of the mirror is pi * r * r * h where r (radius) is 18
> > inches, and h (height) is 2.5 inches.  That means 2543 cubic inches of
> > glass or 1.47 cubic feet.  I'm just guessing the specific gravity of
> > glass is about 3 so we have about 275 pounds.   Of course, I am
ignoring
> > the glass that is removed for the actual figure of the mirror but I'd
> > think this mirror would be well over 100 pounds.
> >
> > - Bill
> >
> > |
> >
________________________________________________________________________
> > |
> > | 1. 36 Inch Mirror Blank
> > |     Posted by: "ghb959" ghberry@... ghb959
> > |     Date: Sun Dec 31, 2006 8:55 am ((PST))
> > |
> > | Hi; I am a new member that just join. And I have work out a big
mirror
> > | blank design. The mirror blank will be of a fuse glass design. 2 1/2
> > | inches thick and 36 inches in diameter. The weight should be
around a
> > | 100 pounds or less. The top glass will be slump to the F Ratio you
> > | want and the bottom will be flat making it easier to grind and make
> > | the mirror cell. I need at least four more people that would want to
> > | buy a mirror blank for my project to go ahead. Late summer would be
> > | the time to received the blanks. Thank You Gordon Berry
> > |
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date:
12/29/2006
> >
> >
>

Hi Gregg;
This is still in the planning stage I will check into it. I do not known all the
mechanical properties of BVC glass.
Here is the web site for A.J. shop in Canada
www.ajstelescopeworkshop.ca he does have charts on all the properties of the
glass. If you want to check it out.
Thank you for your input and hopefully I will have more information to pass on
this project as it comes available. If any one out there thinks that there needs
to be more support in the middle between the ribs please let me known. Or any
other ideals on how to tackle this problem please let me known.
Thank You
Gordon Berry

----- Original Message -----
   From: Gregg
   To: bigdob@yahoogroups.com
   Sent: Monday, January 01, 2007 8:04 PM
   Subject: [bigdob] Re: 36 Inch Mirror Blank


   Some ribbed blanks that are fused together suffer from "print-through"
   of the pattern into the front surface. This may be true even if the
   mirror has been fine annealed, ground and polished. When it goes
   through a temperature adjustment (as all mirrors do when used out of
   doors) there may be a noticable change in the quality of the figure
   that was tested under closely-controlled indoor temperature. There is
   a backup Hubble main mirror of 97.5"x13" of zero-expansion glass that
   is a sandwich of front and rear plates and a central honeycomb,
   avoiding 80% of the weight of a solid disk. It was polished and
   figured at the approximate operating temperature it could experience
   in the Space Telescope in orbit. It has shown no structural problems.
   Mirror structures made from a higher coefficient of expansion material
   will have higher stresses on the joints than ones of more stable
   glasses. This may be true with BVC glass vs. Pyrex or Zerodur.
   A 16 inch Pyrex ribbed mirror that was used in a friend's
   Newtonian/Cassegrain fell apart when he lifted it out of the cell for
   cleaning. He lost 1/3 of the front part. I think a few years of
   desert hot days and cold nights did that mirror in.

   --- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@...>
   wrote:
   >
   > Hi Bill;
   > I do not have the total weight figure out but it the total mass of
   glass
   > weight less then
   > 150 pounds I will still be happy.
   > I do not have a cost on the material at this time?
   > Everything will be made out of BVC glass. The top and bottom pieces
   will be
   > a 1/2 thick glass.
   > The top piece of glass will be ground flat and slump to the F Ratio.
   > There will be eight ribs 1 1/2 wide by 1/2 inch thick cut to the F
   Ratio.
   > The left over material will be cut and use to fill up the edge.
   > Then the glass will be put in a oven and fuse.
   > I have a 12 inch mirror out of BVC glass and it is nice to work with. It
   > take half the time to grind and polish then Pyrex take.
   > I got the ideal from looking in a old Sky and Telescope magazine.
   But the
   > one problem in fusing the glass is everything was stack and fuse and
   slump
   > with the F Ratio at the same time. Making the bottom also slump and
   hard to
   > work.
   > All the material use will be precut.
   > http://www.ajstelescopeworkshop.ca/ AJ told me he would work up a
   price for
   > me in January but I would need at least four more orders. He told me my
   > design would work.
   > He does outstanding work. The reason I went with the fuse concept
   was the
   > great savings on weight. A 32 inch 2 1/4 thick mirror blank out of
   BVC glass
   > weight around 175 pounds.
   > I hoped I answer most of your question this design will work and the
   total
   > weight of the scope should also come down.
   > This has been a goal of mine for over ten years and I filling very good
   > about completing it.
   > I am hoping that if five or more of us buy a blank that the price
   will come
   > down.
   > Thank You
   > Gordon Berry
   >
   >
   > Two each mirror blanks is a 1/2 inch thick.
   > Eight ribs space apart is 4.5 inches on center.
   > ----- Original Message -----
   > From: "William Schwittek" <syzygy@...>
   > To: "MAIL LIST: Bigdob" <bigdob@yahoogroups.com>
   > Sent: Monday, January 01, 2007 8:46 AM
   > Subject: Re: [bigdob] 36 Inch Mirror Blank
   >
   >
   > > I'm guessing that blank will weigh much more than 100 pounds.
   > >
   > > The volume of the mirror is pi * r * r * h where r (radius) is 18
   > > inches, and h (height) is 2.5 inches. That means 2543 cubic inches of
   > > glass or 1.47 cubic feet. I'm just guessing the specific gravity of
   > > glass is about 3 so we have about 275 pounds. Of course, I am
   ignoring
   > > the glass that is removed for the actual figure of the mirror but I'd
   > > think this mirror would be well over 100 pounds.
   > >
   > > - Bill
   > >
   > > |
   > >
   __________________________________________________________
   > > |
   > > | 1. 36 Inch Mirror Blank
   > > | Posted by: "ghb959" ghberry@... ghb959
   > > | Date: Sun Dec 31, 2006 8:55 am ((PST))
   > > |
   > > | Hi; I am a new member that just join. And I have work out a big
   mirror
   > > | blank design. The mirror blank will be of a fuse glass design. 2 1/2
   > > | inches thick and 36 inches in diameter. The weight should be
   around a
   > > | 100 pounds or less. The top glass will be slump to the F Ratio you
   > > | want and the bottom will be flat making it easier to grind and make
   > > | the mirror cell. I need at least four more people that would want to
   > > | buy a mirror blank for my project to go ahead. Late summer would be
   > > | the time to received the blanks. Thank You Gordon Berry
   > > |
   > >
   > >
   > >
   > >
   > > Yahoo! Groups Links
   > >
   > >
   > >
   > >
   > >
   > > --
   > > No virus found in this incoming message.
   > > Checked by AVG Free Edition.
   > > Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date:
   12/29/2006
   > >
   > >
   >






------------------------------------------------------------------------------


   No virus found in this incoming message.
   Checked by AVG Free Edition.
   Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date: 12/29/2006


[Non-text portions of this message have been removed]

I read on a webpage (http://www.oldham-optical.co.uk/Glass.htm) where
BVC has a TCoE of 2.4-2.8 while Pyrex or equivalent is 3.2 and fused
silica is 0.55, and Zerodur or ULE is 0.05 or less.  BVC also has
slightly stiffer resistance to flexure.  It may be less expensive than
other choices in sizes larger than 16".
BVC is known to be softer than plate, which is softer than Pyrex.  It
might be easier to work, also easier to go too deep when polishing and
figuring.  An extra-smooth surface polish may be difficult.

--- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@...>
wrote:
>
> Hi Gregg;
> This is still in the planning stage I will check into it. I do not
known all the mechanical properties of BVC glass.
> Here is the web site for A.J. shop in Canada
> www.ajstelescopeworkshop.ca he does have charts on all the
properties of the glass. If you want to check it out.
> Thank you for your input and hopefully I will have more information
to pass on this project as it comes available. If any one out there
thinks that there needs to be more support in the middle between the
ribs please let me known. Or any other ideals on how to tackle this
problem please let me known.
> Thank You
> Gordon Berry
>
> ----- Original Message -----
>   From: Gregg
>   To: bigdob@yahoogroups.com
>   Sent: Monday, January 01, 2007 8:04 PM
>   Subject: [bigdob] Re: 36 Inch Mirror Blank
>
>
>   Some ribbed blanks that are fused together suffer from "print-through"
>   of the pattern into the front surface. This may be true even if the
>   mirror has been fine annealed, ground and polished. When it goes
>   through a temperature adjustment (as all mirrors do when used out of
>   doors) there may be a noticable change in the quality of the figure
>   that was tested under closely-controlled indoor temperature. There is
>   a backup Hubble main mirror of 97.5"x13" of zero-expansion glass that
>   is a sandwich of front and rear plates and a central honeycomb,
>   avoiding 80% of the weight of a solid disk. It was polished and
>   figured at the approximate operating temperature it could experience
>   in the Space Telescope in orbit. It has shown no structural problems.
>   Mirror structures made from a higher coefficient of expansion material
>   will have higher stresses on the joints than ones of more stable
>   glasses. This may be true with BVC glass vs. Pyrex or Zerodur.
>   A 16 inch Pyrex ribbed mirror that was used in a friend's
>   Newtonian/Cassegrain fell apart when he lifted it out of the cell for
>   cleaning. He lost 1/3 of the front part. I think a few years of
>   desert hot days and cold nights did that mirror in.
>
>   --- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@>
>   wrote:
>   >
>   > Hi Bill;
>   > I do not have the total weight figure out but it the total mass of
>   glass
>   > weight less then
>   > 150 pounds I will still be happy.
>   > I do not have a cost on the material at this time?
>   > Everything will be made out of BVC glass. The top and bottom pieces
>   will be
>   > a 1/2 thick glass.
>   > The top piece of glass will be ground flat and slump to the F Ratio.
>   > There will be eight ribs 1 1/2 wide by 1/2 inch thick cut to the F
>   Ratio.
>   > The left over material will be cut and use to fill up the edge.
>   > Then the glass will be put in a oven and fuse.
>   > I have a 12 inch mirror out of BVC glass and it is nice to work
with. It
>   > take half the time to grind and polish then Pyrex take.
>   > I got the ideal from looking in a old Sky and Telescope magazine.
>   But the
>   > one problem in fusing the glass is everything was stack and fuse and
>   slump
>   > with the F Ratio at the same time. Making the bottom also slump and
>   hard to
>   > work.
>   > All the material use will be precut.
>   > http://www.ajstelescopeworkshop.ca/ AJ told me he would work up a
>   price for
>   > me in January but I would need at least four more orders. He
told me my
>   > design would work.
>   > He does outstanding work. The reason I went with the fuse concept
>   was the
>   > great savings on weight. A 32 inch 2 1/4 thick mirror blank out of
>   BVC glass
>   > weight around 175 pounds.
>   > I hoped I answer most of your question this design will work and the
>   total
>   > weight of the scope should also come down.
>   > This has been a goal of mine for over ten years and I filling
very good
>   > about completing it.
>   > I am hoping that if five or more of us buy a blank that the price
>   will come
>   > down.
>   > Thank You
>   > Gordon Berry
>   >
>   >
>   > Two each mirror blanks is a 1/2 inch thick.
>   > Eight ribs space apart is 4.5 inches on center.
>   > ----- Original Message -----
>   > From: "William Schwittek" <syzygy@>
>   > To: "MAIL LIST: Bigdob" <bigdob@yahoogroups.com>
>   > Sent: Monday, January 01, 2007 8:46 AM
>   > Subject: Re: [bigdob] 36 Inch Mirror Blank
>   >
>   >
>   > > I'm guessing that blank will weigh much more than 100 pounds.
>   > >
>   > > The volume of the mirror is pi * r * r * h where r (radius) is 18
>   > > inches, and h (height) is 2.5 inches. That means 2543 cubic
inches of
>   > > glass or 1.47 cubic feet. I'm just guessing the specific
gravity of
>   > > glass is about 3 so we have about 275 pounds. Of course, I am
>   ignoring
>   > > the glass that is removed for the actual figure of the mirror
but I'd
>   > > think this mirror would be well over 100 pounds.
>   > >
>   > > - Bill
>   > >
>   > > |
>   > >
>   __________________________________________________________
>   > > |
>   > > | 1. 36 Inch Mirror Blank
>   > > | Posted by: "ghb959" ghberry@ ghb959
>   > > | Date: Sun Dec 31, 2006 8:55 am ((PST))
>   > > |
>   > > | Hi; I am a new member that just join. And I have work out a big
>   mirror
>   > > | blank design. The mirror blank will be of a fuse glass
design. 2 1/2
>   > > | inches thick and 36 inches in diameter. The weight should be
>   around a
>   > > | 100 pounds or less. The top glass will be slump to the F
Ratio you
>   > > | want and the bottom will be flat making it easier to grind
and make
>   > > | the mirror cell. I need at least four more people that would
want to
>   > > | buy a mirror blank for my project to go ahead. Late summer
would be
>   > > | the time to received the blanks. Thank You Gordon Berry
>   > > |
>   > >
>   > >
>   > >
>   > >
>   > > Yahoo! Groups Links
>   > >
>   > >
>   > >
>   > >
>   > >
>   > > --
>   > > No virus found in this incoming message.
>   > > Checked by AVG Free Edition.
>   > > Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date:
>   12/29/2006
>   > >
>   > >
>   >
>
>
>
>
>
>
>
------------------------------------------------------------------------------
>
>
>   No virus found in this incoming message.
>   Checked by AVG Free Edition.
>   Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date:
12/29/2006
>
>
> [Non-text portions of this message have been removed]
>

Hi,

I think the first step would be to find a mirror maker that will handle
the BVC glass.  I have a 18.5" BVC mirror and my mirror maker went
through a lot of time and effort to get mine completed.  BVC glass is
not the easiest glass to figure. If you are planning on making the
mirror yourself I would re-think the BVC glass unless you have had
several large mirrors under your belt.

Dave
18.5 f4.5 BVC DOB

--- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@...>
wrote:
>I have a 12 inch mirror out of BVC glass and it is nice to work with. It
> take half the time to grind and polish then Pyrex take.
> I got the ideal from looking in a old Sky and Telescope magazine.
But the
> one problem in fusing the glass is everything was stack and fuse and
slump
> with the F Ratio at the same time. Making the bottom also slump and
>hard to
> work.

Being the person who wrote that S&T article,having the blank evenly
curved is far stiffer than one having a flat bottom.I never found it
to be a problem when working any of my fused blanks.


> All the material use will be precut.
> http://www.ajstelescopeworkshop.ca/  AJ told me he would work up a
price for
> me in January but I would need at least four more orders. He told me my
> design would work.
> He does outstanding work. The reason I went with the fuse concept
was the
> great savings on weight. A 32 inch 2 1/4 thick mirror blank out of
BVC glass
> weight around 175 pounds.
> I hoped I answer most of your question this design will work and the
total
> weight of the scope should also come down.

You might consider a plate glass or pyrex, fused cellular blank made
by Jean_Guy Moreau in Quebec.One of his 36 incher is being done by
Norm Fullman. Jean Moreau has worked on his cellular glass designs for
many years.He can be found on the atm list (http://www.atmlist.net)
and the yahoo group:atm_free.He does sell a few every year and does
place ads on Astromart and you can order just one at a time from 12 to
36 incher.Tell Jean Ric sent you.

> This has been a goal of mine for over ten years and I filling very good
> about completing it.

Sooner than you think,

Ric Rokosz

--- In bigdob@yahoogroups.com, "Gregg" <starryskyn@...> wrote:

> A 16 inch Pyrex ribbed mirror that was used in a friend's
> Newtonian/Cassegrain fell apart when he lifted it out of the cell for
> cleaning.  He lost 1/3 of the front part.  I think a few years of
> desert hot days and cold nights did that mirror in.
>

Do you know who made that mirror?

I did a 14 inch fused cellular of pyrex written up in S&T,back in
1983, that when finished was stored in a metal garden shed for  12
years.The temp varied from -20 to over 40 deg C over the year and the
mirror still holds it's figure to this day.The problem your friend's
mirror had was in the manufacturing process,not the idea of fused
celluars.Any cast/fused mirror will have a printthrough problem to
some degree,the pro's make allownaces for this.There is a trade off
between lightweight/stiffness and figure quality.The pro's get around
this my either ion milling the blank,(no pressure on the faceplate
really) or using a counter air pressure to stop the slight sag between
cells.Fused cellulars can be made with no printthrough,just a problem
of technique.

Ric

Mike Lockwood did a 32" BVC recently:
http://bi-staff.beckman.uiuc.edu/~melockwo/telescopes/holmes32/holmes32.html

He does nice work.  He did a 8.25" Minor axis diagonal
for my 32" and he did a fantastic job on it.


Scott




--- In bigdob@yahoogroups.com, "burgman1" <burgman1@...> wrote:
>
> Hi,
>
> I think the first step would be to find a mirror maker that will handle
> the BVC glass.  I have a 18.5" BVC mirror and my mirror maker went
> through a lot of time and effort to get mine completed.  BVC glass is
> not the easiest glass to figure. If you are planning on making the
> mirror yourself I would re-think the BVC glass unless you have had
> several large mirrors under your belt.
>
> Dave
> 18.5 f4.5 BVC DOB
>

Hi Dave;
The only problem so far with the glass I found is you have to be careful when
you are fine grinding at 5 micron because the glass and the tool if allow to dry
out as you are grinding want to stick and will scratch easy. But the scratch
that did happen to me polish out.
The next time I do another mirror I am going to try to add a little soap to the
mix during fine grinding.
And I also have found out when figuring. Is not to go around the glass more
three time. That is enough to effect a change.
My friend is also doing a 12 inch BVC mirror
and he also love the glass. It is so easy to work.
Gordon
   ----- Original Message -----
   From: burgman1
   To: bigdob@yahoogroups.com
   Sent: Tuesday, January 02, 2007 8:38 AM
   Subject: [bigdob] Re: 36 Inch Mirror Blank


   Hi,

   I think the first step would be to find a mirror maker that will handle
   the BVC glass. I have a 18.5" BVC mirror and my mirror maker went
   through a lot of time and effort to get mine completed. BVC glass is
   not the easiest glass to figure. If you are planning on making the
   mirror yourself I would re-think the BVC glass unless you have had
   several large mirrors under your belt.

   Dave
   18.5 f4.5 BVC DOB






------------------------------------------------------------------------------


   No virus found in this incoming message.
   Checked by AVG Free Edition.
   Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date: 12/29/2006


[Non-text portions of this message have been removed]

Hi Scott;
This what I trying to get to!!!
And I did find a book at our local library.
And it is call Warm Glass: A complete guide to forming techniques fusing,
slumping and casting.
I thank everyone for there input on this. I think going to read up more on this
subject and hopefully I will have a big mirror or one expensive tabletop piece
to talk about.
Gordon
   ----- Original Message -----
   From: Polaraligned
   To: bigdob@yahoogroups.com
   Sent: Tuesday, January 02, 2007 5:53 PM
   Subject: [bigdob] Re: 36 Inch Mirror Blank


   Mike Lockwood did a 32" BVC recently:
   http://bi-staff.beckman.uiuc.edu/~melockwo/telescopes/holmes32/holmes32.html

   He does nice work. He did a 8.25" Minor axis diagonal
   for my 32" and he did a fantastic job on it.

   Scott

   --- In bigdob@yahoogroups.com, "burgman1" <burgman1@...> wrote:
   >
   > Hi,
   >
   > I think the first step would be to find a mirror maker that will handle
   > the BVC glass. I have a 18.5" BVC mirror and my mirror maker went
   > through a lot of time and effort to get mine completed. BVC glass is
   > not the easiest glass to figure. If you are planning on making the
   > mirror yourself I would re-think the BVC glass unless you have had
   > several large mirrors under your belt.
   >
   > Dave
   > 18.5 f4.5 BVC DOB
   >






------------------------------------------------------------------------------


   No virus found in this incoming message.
   Checked by AVG Free Edition.
   Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date: 12/29/2006


[Non-text portions of this message have been removed]

I'd like to know if any of y'all big dob guys have seen them thar
teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
could give particulars of the location, altitude, eyepieces etc. with
which you made the aforementioned observation of the G and H varmints.

thank you
Greg N

Greg
   See if this helps with the location

http://www.laughton.com/paul/rfo/trap/trap.html

Buck


--- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@...> wrote:
>
> I'd like to know if any of y'all big dob guys have seen them thar
> teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> could give particulars of the location, altitude, eyepieces etc. with
> which you made the aforementioned observation of the G and H varmints.
>
> thank you
> Greg N
>

Hi Greg and the best of the season to you... this is a post I
recently placed on the Obsession group - in a nut shell it is not
easy!

Recently I was invited to use the Mt Bigelow 61" telescope owned and
operated by Stewart Labs. It is a beautiful instrument - first built
specifically for the NASA program to land a man on the moon ... it is
the instrument that was used to find a landing site on the moon. At
f13.7 it is F-LONG (~20 Meters!).

Unfortunately this night was not the best - seeing was ok. It has to
be pretty good to use it since the lowest power available is 400x
with an 8 arcmin field. The Eskimo was incredible with loads of
detail...

one interesting item we pulled up, on my request, was the Trapezium.
First let me say that the nebulous detail in the cloud was just out
of this world (I know - LITERALLY)! It would have been great if the
seeing were just a little bit better...

I wanted to pull the Trap up to see if I could see, for what I
believe to be the first time, the G and H stars in the Trap. The
bottom line is - even though they are both less than 15th mag these
are TOUGH items! Even with a 1.5 meter telescope I was not able to
see the G star. It is too close to the C and the glare is just too
high. Perhaps (and probably) if the seeing had been better it would
have been see-able. The H on the other hand was seen. It forms a nice
isosceles triangle with the two end stars (A and C). But it was NOT
a "no-brainer"... it was still tough!

Gary Myers
StellarCAT



--- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@...> wrote:
>
> I'd like to know if any of y'all big dob guys have seen them thar
> teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> could give particulars of the location, altitude, eyepieces etc.
with
> which you made the aforementioned observation of the G and H
varmints.
>
> thank you
> Greg N
>

I'm limited to 14" or my friend's 15".  E and F we see regularly but G
and H in our aperture range, in our skies, are in the "fuhgetaboutit"
category.   There are a lot of light buckets on this group and I
figured someone here may have done the deed.  thanks Greg N


--- In bigdob@yahoogroups.com, "buck8one2" <Buck8one2@...> wrote:
>
> Greg
>   See if this helps with the location
>
> http://www.laughton.com/paul/rfo/trap/trap.html
>
> Buck
>
>
> --- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@> wrote:
> >
> > I'd like to know if any of y'all big dob guys have seen them thar
> > teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> > could give particulars of the location, altitude, eyepieces etc. with
> > which you made the aforementioned observation of the G and H varmints.
> >
> > thank you
> > Greg N
> >
>

On amastro Mike Kerr recounts having resolved H once, as a double, in
a 25" scope, but says he hasn't been able to duplicate it.

regards
Greg N

--- In bigdob@yahoogroups.com, "Gary Myers" <RXDesign@...> wrote:
>
> Hi Greg and the best of the season to you... this is a post I
> recently placed on the Obsession group - in a nut shell it is not
> easy!
>
> Recently I was invited to use the Mt Bigelow 61" telescope owned and
> operated by Stewart Labs. It is a beautiful instrument - first built
> specifically for the NASA program to land a man on the moon ... it is
> the instrument that was used to find a landing site on the moon. At
> f13.7 it is F-LONG (~20 Meters!).
>
> Unfortunately this night was not the best - seeing was ok. It has to
> be pretty good to use it since the lowest power available is 400x
> with an 8 arcmin field. The Eskimo was incredible with loads of
> detail...
>
> one interesting item we pulled up, on my request, was the Trapezium.
> First let me say that the nebulous detail in the cloud was just out
> of this world (I know - LITERALLY)! It would have been great if the
> seeing were just a little bit better...
>
> I wanted to pull the Trap up to see if I could see, for what I
> believe to be the first time, the G and H stars in the Trap. The
> bottom line is - even though they are both less than 15th mag these
> are TOUGH items! Even with a 1.5 meter telescope I was not able to
> see the G star. It is too close to the C and the glare is just too
> high. Perhaps (and probably) if the seeing had been better it would
> have been see-able. The H on the other hand was seen. It forms a nice
> isosceles triangle with the two end stars (A and C). But it was NOT
> a "no-brainer"... it was still tough!
>
> Gary Myers
> StellarCAT
>
>
>
> --- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@> wrote:
> >
> > I'd like to know if any of y'all big dob guys have seen them thar
> > teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> > could give particulars of the location, altitude, eyepieces etc.
> with
> > which you made the aforementioned observation of the G and H
> varmints.
> >
> > thank you
> > Greg N
> >
>

Yeah the amastro group has on file a report of a sighting in the 82"
at Macdonald in TX and the 60" at Mt. Wilson.  regards Greg N

--- In bigdob@yahoogroups.com, "Gary Myers" <RXDesign@...> wrote:
>
> Hi Greg and the best of the season to you... this is a post I
> recently placed on the Obsession group - in a nut shell it is not
> easy!
>
> Recently I was invited to use the Mt Bigelow 61" telescope owned and
> operated by Stewart Labs. It is a beautiful instrument - first built
> specifically for the NASA program to land a man on the moon ... it is
> the instrument that was used to find a landing site on the moon. At
> f13.7 it is F-LONG (~20 Meters!).
>
> Unfortunately this night was not the best - seeing was ok. It has to
> be pretty good to use it since the lowest power available is 400x
> with an 8 arcmin field. The Eskimo was incredible with loads of
> detail...
>
> one interesting item we pulled up, on my request, was the Trapezium.
> First let me say that the nebulous detail in the cloud was just out
> of this world (I know - LITERALLY)! It would have been great if the
> seeing were just a little bit better...
>
> I wanted to pull the Trap up to see if I could see, for what I
> believe to be the first time, the G and H stars in the Trap. The
> bottom line is - even though they are both less than 15th mag these
> are TOUGH items! Even with a 1.5 meter telescope I was not able to
> see the G star. It is too close to the C and the glare is just too
> high. Perhaps (and probably) if the seeing had been better it would
> have been see-able. The H on the other hand was seen. It forms a nice
> isosceles triangle with the two end stars (A and C). But it was NOT
> a "no-brainer"... it was still tough!
>
> Gary Myers
> StellarCAT
>
>
>
> --- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@> wrote:
> >
> > I'd like to know if any of y'all big dob guys have seen them thar
> > teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> > could give particulars of the location, altitude, eyepieces etc.
> with
> > which you made the aforementioned observation of the G and H
> varmints.
> >
> > thank you
> > Greg N
> >
>

Likewise I can see e and f in DC just 1000 meters north of USNO
pretty regularly with my O 15"

	 Never a wisp of g or h, though.

Steve Truitt
On Jan 3, 2007, at 9:52 AM, gnowellsct wrote:

> I'm limited to 14" or my friend's 15". E and F we see regularly but G
> and H in our aperture range, in our skies, are in the "fuhgetaboutit"
> category. T


[Non-text portions of this message have been removed]

Greg,

I have never done so, but a very respected local observer with a 15"
Obsession recently told me that he had G and H flickering in- and out-
of view at a big star party down south some time back. I don't know
much more in terms of details of magnification, etc., but I'd bet the
seeing would have had to have been unbelievable.

I'm going to have to spend some time trying...they may not be visible
to me (Iowa's winter skies are typically pretty turbulent), but it will
be a good excuse to get out my dob!

Clear skies,
Matt

--- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@...> wrote:
>
> I'd like to know if any of y'all big dob guys have seen them thar
> teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> could give particulars of the location, altitude, eyepieces etc. with
> which you made the aforementioned observation of the G and H varmints.
>
> thank you
> Greg N
>

Hi Greg,

That's a yes here.

G & H through a 22" F/6 at 830X using a Widescan 8mm and 2X Barlow
from 6300 feet in Meyers, Calif. on an excellent night of course.

Neither were easy but confirmed by a friend who saw the G, only. H was
seen only by me and was seen as single, not double. All six main stars
of the group were seen clearly resolved at 100X.

All the best,

John Lightholder

--- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@...> wrote:
>
> I'd like to know if any of y'all big dob guys have seen them thar
> teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> could give particulars of the location, altitude, eyepieces etc. with
> which you made the aforementioned observation of the G and H
varmints.
>
> thank you
> Greg N
>

Greg,
On a night of exceptional transparency and seeing, I managed to view G
and H (using averted vision) in my 12.5" at Mt. Pinos in SoCal (8350').
The night sky brightness at the time was around 21.62, and the seeing
was sub-arcsecond. I had enough power to see H as double, but its
intermittent visibility rendered that impossible.
On the same night, the Horsehead was visible without a filter and
NGC1977 was distinctly blue.
I don't know if that is the smallest possible aperture for G and H, but I
could definitely NOT see them in my 5" Mak :-)
Don Pensack


--- In bigdob@yahoogroups.com, "John Lightholder" <lpo@...> wrote:
>
> Hi Greg,
>
> That's a yes here.
>
> G & H through a 22" F/6 at 830X using a Widescan 8mm and 2X
Barlow
> from 6300 feet in Meyers, Calif. on an excellent night of course.
>
> Neither were easy but confirmed by a friend who saw the G, only. H
was
> seen only by me and was seen as single, not double. All six main stars
> of the group were seen clearly resolved at 100X.
>
> All the best,
>
> John Lightholder
>
> --- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@> wrote:
> >
> > I'd like to know if any of y'all big dob guys have seen them thar
> > teenny G and H varmints *VISUALLY* in that thar M42 Trap and if
you
> > could give particulars of the location, altitude, eyepieces etc. with
> > which you made the aforementioned observation of the G and H
> varmints.
> >
> > thank you
> > Greg N
> >
>

Hi,

--- In bigdob@yahoogroups.com, "Polaraligned" <polaraligned@...> wrote:
> Mike Lockwood did a 32" BVC recently:
http://bi-staff.beckman.uiuc.edu/~melockwo/telescopes/holmes32/holmes32.html
> He does nice work.  He did a 8.25" Minor axis diagonal
> for my 32" and he did a fantastic job on it.

Thanks, Scott.

My current machine could probably be configured to handle a 36" blank,
but I am planning a larger machine, too.  36" shouldn't be a problem.

I can email you privately if you wish.

Mike Lockwood
http://bi-staff.beckman.uiuc.edu/~melockwo/index.html

even in 61" I could not see H'!


g.


--- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@...> wrote:
>
> On amastro Mike Kerr recounts having resolved H once, as a double,
in
> a 25" scope, but says he hasn't been able to duplicate it.
>
> regards
> Greg N
>
> --- In bigdob@yahoogroups.com, "Gary Myers" <RXDesign@> wrote:
> >
> > Hi Greg and the best of the season to you... this is a post I
> > recently placed on the Obsession group - in a nut shell it is not
> > easy!
> >
> > Recently I was invited to use the Mt Bigelow 61" telescope owned
and
> > operated by Stewart Labs. It is a beautiful instrument - first
built
> > specifically for the NASA program to land a man on the moon ...
it is
> > the instrument that was used to find a landing site on the moon.
At
> > f13.7 it is F-LONG (~20 Meters!).
> >
> > Unfortunately this night was not the best - seeing was ok. It has
to
> > be pretty good to use it since the lowest power available is 400x
> > with an 8 arcmin field. The Eskimo was incredible with loads of
> > detail...
> >
> > one interesting item we pulled up, on my request, was the
Trapezium.
> > First let me say that the nebulous detail in the cloud was just
out
> > of this world (I know - LITERALLY)! It would have been great if
the
> > seeing were just a little bit better...
> >
> > I wanted to pull the Trap up to see if I could see, for what I
> > believe to be the first time, the G and H stars in the Trap. The
> > bottom line is - even though they are both less than 15th mag
these
> > are TOUGH items! Even with a 1.5 meter telescope I was not able to
> > see the G star. It is too close to the C and the glare is just too
> > high. Perhaps (and probably) if the seeing had been better it
would
> > have been see-able. The H on the other hand was seen. It forms a
nice
> > isosceles triangle with the two end stars (A and C). But it was
NOT
> > a "no-brainer"... it was still tough!
> >
> > Gary Myers
> > StellarCAT
> >
> >
> >
> > --- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@> wrote:
> > >
> > > I'd like to know if any of y'all big dob guys have seen them
thar
> > > teenny G and H varmints *VISUALLY* in that thar M42 Trap and if
you
> > > could give particulars of the location, altitude, eyepieces
etc.
> > with
> > > which you made the aforementioned observation of the G and H
> > varmints.
> > >
> > > thank you
> > > Greg N
> > >
> >
>

Hi Mike;
Please email at ghberry@... I need a diagonal mirror this spring.
Thank You
Gordon Berry

   ----- Original Message -----
   From: Mike Lockwood
   To: bigdob@yahoogroups.com
   Sent: Wednesday, January 03, 2007 5:39 PM
   Subject: [bigdob] Re: 36 Inch Mirror Blank


   Hi,

   --- In bigdob@yahoogroups.com, "Polaraligned" <polaraligned@...> wrote:
   > Mike Lockwood did a 32" BVC recently:
   http://bi-staff.beckman.uiuc.edu/~melockwo/telescopes/holmes32/holmes32.html
   > He does nice work. He did a 8.25" Minor axis diagonal
   > for my 32" and he did a fantastic job on it.

   Thanks, Scott.

   My current machine could probably be configured to handle a 36" blank,
   but I am planning a larger machine, too. 36" shouldn't be a problem.

   I can email you privately if you wish.

   Mike Lockwood
   http://bi-staff.beckman.uiuc.edu/~melockwo/index.html






------------------------------------------------------------------------------


   No virus found in this incoming message.
   Checked by AVG Free Edition.
   Version: 7.1.409 / Virus Database: 268.16.0/609 - Release Date: 12/29/2006


[Non-text portions of this message have been removed]

Thanks all.  It seems that mid teens on up G and H become *possible*
but that even 60" isn't a guarantee.  As usual it's the swimming pool
over our heads which reigns supreme.  The 12.5" report is impressive!
  Sounds like it's really a once in a lifetime thing and that even then
you have to be living somewhere where conditions are *typically*
excellent.

regards
greg N


--- In bigdob@yahoogroups.com, "John Lightholder" <lpo@...> wrote:
>
> Hi Greg,
>
> That's a yes here.
>
> G & H through a 22" F/6 at 830X using a Widescan 8mm and 2X Barlow
> from 6300 feet in Meyers, Calif. on an excellent night of course.
>
> Neither were easy but confirmed by a friend who saw the G, only. H was
> seen only by me and was seen as single, not double. All six main stars
> of the group were seen clearly resolved at 100X.
>
> All the best,
>
> John Lightholder
>
> --- In bigdob@yahoogroups.com, "gnowellsct" <tim71pos@> wrote:
> >
> > I'd like to know if any of y'all big dob guys have seen them thar
> > teenny G and H varmints *VISUALLY* in that thar M42 Trap and if you
> > could give particulars of the location, altitude, eyepieces etc. with
> > which you made the aforementioned observation of the G and H
> varmints.
> >
> > thank you
> > Greg N
> >
>

I've notice that on refractor groups they spend a lot of time talkng
about a the Airy disk in reltaion to doubles and there's a lot of
knowledgeable discussion about when and how the Airy interferes with
splitting etc. as a fucntion of secondary obstruction etc.

On the bigger aperture groups I hardly ever see this discussed.  My
thought is taht it's not disussed because the Airy disks are
intrinsically smaller and rarely seen because seeing conditiosn don't
allow them to be seen.

Certainly it was a surprise to me when I ot a 4" ED refractor and
began seeing the Airy "routinely" when I dropped in a 5 or 3.5mm
eyepiece.

It is true that I live in a region with poor seeing (upstate NY) but
it is also true that the ONLY time I've had an Airy ring pattern
interefere with my doubles splitting is in my 4" and 5" refractors.
In the 14" I've never had the problem.  But then, I've never had sub
arc second seeing.

Is your collective sense that the airy is not talked about much in
groups with larger instruments because the Airy is typically smalle
rthan seeing conditions permit viewing it?

regartds
Greg N

Hi Greg,

I think you have summed it up perfectly.

In my experience it is rare to see Airy discs in telescopes larger than 8" --
let alone the average 'scope on this list which I guess is about 16".

In the many years I relied on my old 10" f/6 workhorse, I only had one night
when I saw really well, almost perfectly formed diffraction rings -- it was in
1995 while observing Gamma Sextantis on a night of superb seeing. I was using
x562, and the separation between the exactly equal mag 6 components was 0.52" --
I saw it as separate with  first rings overlapping the adjacent disc, but a tiny
space between the two stars.  The Dawes limit for the 10" is 0.45" -- so  that
is very close to the best possible resolving power -- at least according to
Dawes.

Using the C-14 you would actually be more likely to see diffraction rings than
in an equivalent Newtonian. Why?  The size of the secondary mirror is so much
larger and more energy is pushed out from the disc into the diffraction rings
making them brighter and easy to see (though still extraordinarily rare in a
14").

Cheers & Clear Skies,


Les D

The laws of Thermodynamics (summarised)

1st Law:    You can't win.
2nd Law:   You can't break even.
3rd Law:    You can't leave the game.

   ----- Original Message -----
   From: gnowellsct
   To: bigdob@yahoogroups.com
   Sent: Friday, January 05, 2007 5:05 PM
   Subject: [bigdob] airy disk


   I've notice that on refractor groups they spend a lot of time talkng
   about a the Airy disk in reltaion to doubles and there's a lot of
   knowledgeable discussion about when and how the Airy interferes with
   splitting etc. as a fucntion of secondary obstruction etc.

   On the bigger aperture groups I hardly ever see this discussed. My
   thought is taht it's not disussed because the Airy disks are
   intrinsically smaller and rarely seen because seeing conditiosn don't
   allow them to be seen.

   Certainly it was a surprise to me when I ot a 4" ED refractor and
   began seeing the Airy "routinely" when I dropped in a 5 or 3.5mm
   eyepiece.

   It is true that I live in a region with poor seeing (upstate NY) but
   it is also true that the ONLY time I've had an Airy ring pattern
   interefere with my doubles splitting is in my 4" and 5" refractors.
   In the 14" I've never had the problem. But then, I've never had sub
   arc second seeing.

   Is your collective sense that the airy is not talked about much in
   groups with larger instruments because the Airy is typically smalle
   rthan seeing conditions permit viewing it?

   regartds
   Greg N





[Non-text portions of this message have been removed]

Hi,

--- In bigdob@yahoogroups.com, "Les Dalrymple" <lesdal@...> wrote:
> In my experience it is rare to see Airy discs in telescopes larger
> than 8" -- let alone the average 'scope on this list which I guess
> is about 16".
> In the many years I relied on my old 10" f/6 workhorse, I only had
> one night when I saw really well, almost perfectly formed
> diffraction rings -- it was in 1995 while observing Gamma Sextantis
> on a night of superb seeing. I was using x562,

In my experience, seeing them in a 6" F/8 reflector is not difficult
so long as the optics are cooled off.

I often see them in my 10" telescopes (F/5.5, F/8.8) if the seeing is
good, but rarely is the air still enough to show them perfectly formed
and steady.

I have viewed one component of the double-double at ~1200X with my
12.5" classical Cassegrain on a good night when it was nearly at the
zenith.  Rings, though moving, were plainly visible around both stars,
with a ton of space between them.  At 1200X only one of the doubles
would fit in the field of view.

I suspect the effect you mention below makes it easier to see rings in
my Cassegrain, since it has about a 32% obstruction, while my 10"
Newtonians have much less.

> Using the C-14 you would actually be more likely to see diffraction
> rings than in an equivalent Newtonian. Why?  The size of the
> secondary mirror is so much larger and more energy is pushed out
> from the disc into the diffraction rings making them brighter and
> easy to see (though still extraordinarily rare in a 14").

To me, a higher focal ratio makes the rings easier to see, probably
because they are not overwhelmed by coma if the star is slightly
off-center or the telescope is not perfectly collimated.  There is
less aberration from eyepieces, too.

Mike Lockwood
http://bi-staff.beckman.uiuc.edu/~melockwo/index.html

Gordon,

--- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@...>
wrote:
> Please email at ghberry@... I need a diagonal mirror this spring.
> Thank You
> Gordon Berry

Somehow the last part of your email got chopped off.  You can try to
post it again or you can find my private email address by searching
through the ATM archives for messages I've posted.

Sorry to clutter up the group with this.

Mike Lockwood

Yahoo deletes email addresses after the @ sign if you're reading messages on
the group page.  Gordon's email was ghberry(at)earthlink.net.

-John


--- Mike Lockwood <parabola30@...> wrote:

> Gordon,
>
> --- In bigdob@yahoogroups.com, "Gordon & Sherri Berry" <ghberry@...>
> wrote:
> > Please email at ghberry@... I need a diagonal mirror this spring.
> > Thank You
> > Gordon Berry
>
> Somehow the last part of your email got chopped off.  You can try to
> post it again or you can find my private email address by searching
> through the ATM archives for messages I've posted.
>
> Sorry to clutter up the group with this.
>
> Mike Lockwood
>
>
>
>
> Yahoo! Groups Links
>
>
>
>


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around
http://mail.yahoo.com