Fw: ATM Little Mirror Man.

["Vero and Lisa Joseph" <joseph@interact.net.au>]

----- Original Message -----
From: Vero and Lisa Joseph <joseph@interact.net.au>
To: Mr S. Mitchell <Mitchell@staff.bgs.qld.edu.au>
Sent: Thursday, December 09, 1999 11:40 PM
Subject: Re: ATM Little Mirror Man.


> G'Day
> In terms of time, the mirror took around 9 hours from start to finish. As
I
> mentioned in my original post, the grinding took 3.5 hours. Polishing took
> longer than I expected because (I believe) I used a solid lap rather than
a
> channeled lap. I estimate I could have finished an hour and a half earlier
> with a channelled lap (but the finish or figure may/may not halve been as
> good). The project was very cheap: $1 each for the mirror and tool, the
grit
> and CeO was left over from the last mirror and the pitch recycled from the
> old tool.
>
> However, I made this mirror mainly because the glass was dirt cheap and I
> thought it would be a nice portable and light weight 'scope to take on
> extended trips when space is at a premium in my wagon (wife, three kids
and
> two dogs). My advice FWIW is to make your first a 15 - 20 cm mirror at
least
> 19mm thick. The reasons are the mirror is easier to manage and the larger
> diameter will gather 2 - 4 times more light. Time wise I would estimate
15 -
> 20 hours depending on figuring. Or you could do as I did and make your
first
> mirror spherical. The focal length will have to be long (f9 - f12) but if
> you are careful, no figuring is needed.
>
> Good luck whatever you decide. I hope what I have written above helps.
>
> Vero Joseph
> Goulburn, NSW, Australia (yucky days and yucky nights)
>
Original Message
From: Mr S. Mitchell <Mitchell@staff.bgs.qld.edu.au>
To: Vero and Lisa Joseph <joseph@interact.net.au>

An australian on the list!
I'm new to the list (currently in traning for my first scope)  i really want
my
first scope to be a small one and I'm intrested in the mirror you made
yesterday on the list.

do you mind telling me a bit more about the time involved in doing a small
mirror like this?

Thanks in advance