RE: ATM Grinding a Lens (in ATMJ 16)

["Andersen, Clark R." <clanders@utmb.edu>]

In one sense I would expect that grinding a lense might be simpler than
grinding a paraboloid mirror.  If I recall my optics correctly, the surface
of a lense is spherical, which should be easier to achieve than a
paraboloid.  Of course, there's still that second surface to grind...

-----Original Message-----
From: B. Pepin [mailto:atmjedit@conceptsnet.com]
Sent: Tuesday, September 26, 2000 10:54 AM
To: Guy Brandenburg; Viper71049@aol.com
Cc: atm@shore.net
Subject: Re: ATM Grinding a Lens (in ATMJ 16)



Sounds like you have been listening to impatient people!

Seriously, there is a First Project article on making a 6-inch f/22
single-curve Littrow/Clairaut refractor in the upcoming ATMJ 16. The process
is explained in detail. The work required no specialized equipment, and not
a lot more time than the average beginner might spend on a 6- or 8-inch
mirror. Cost for materials was less than $200.

Barlow


----- Original Message -----
From: Guy Brandenburg <gfbranden@earthlink.net>
To: <Viper71049@aol.com>
Cc: <atm@shore.net>
Sent: Saturday, September 23, 2000 6:52 PM
Subject: Re: ATM Grinding a Lens?


>
> It's going to be a very tough project, much harder than a mirror: you
> have to get 4 surfaces correct, and a lot of them are convex. Very, very
> tricky. Plus the two opposing sides of each lens have to be aligned
> properly, and it's easy to mess that up.
> With a mirror, you only need to get 1 surface correct. Admittedly, it
> needs to be much more correct than the lens surfaces, but still...
> Newport Glass has on its website a number of directions on how to make a
> refractor.
> Good luck, if you really attempt this. Let us know how it goes.
> Guy Brandenburg
>
> Viper71049@aol.com wrote:
> >
> > Hello,
> >
> > My First telescope a 60mm F-13.3 telescope which is useless because of
the small FOV. I am thinking of maybe regrinding the lens to make a 60mm F-4
to F-6.
> > This would give me better FOV and maybe do some quick astrophotgraphy.
Tried to look on the net no how to grind a lens but found only one place
which wasn't that detailed.  Anyone know off a place where I can find this
information. I am starting to do so many projects at once that all I think
about is Telescopes!!
> >
> > Tony
>