Re: ATM Dumb Newbie Question

["James Taylor" <u2pilot@satx.rr.com>]

> So here is my stupid newbie question du juor:
> The blank has some raised lines and markings on it - I assume this is the
> back, and I should grind the other side?  Also, the tool has grooves in it
(I
> think someone said these were grit reservoirs?)  So do I grind with the
> grooved side or the flat side?  While we're at it, any "10 stupid things
> newbies do" lists you'd care to share?


Randy:
    I'm about to start polishing the glass I got from Newport myself...my
first-ever mirror.  I have the same tool you describe with the circular
grooves.  My glass was generated to f/10.  If your tool is already
generated, place the grooved side on a very flat surface and you'll probably
notice that it's not flat.  They intend for the grooved side to be used as
the grinding side of the tool so the grooves work as channels for the grit.

    I'll admit to everyone that I started my grinding on the non-grooved
side of the tool because I didn't realize at the time that they had
generated the grooved side.  However, all turned out well because I wanted
an f/8 curve instead of f/10 and while doing my center over edge strokes to
shorten the focal length I ended up bringing the non-generated side of the
tool right into shape with the blank.  The down side is that I had to
channel that side of the tool manually and I've had to deal with the
slightly convex side of the tool back.  It all worked out in the end ;-)

James