From: "Richard Schwartz" 
To: ,
        "Peter" ,
        
Reply-To: "Richard Schwartz" 


I used an 8" Schmidling tool.   Although it took a while to get good contact
all over the tool, I will say that it is the next best thing to high speed
diamond machining.   I have reason to believe that for fine grinding, one
wet per grit is enough.

I don't agree with some of Jack's politics, but his grinding tools are the
VERY BEST, way better than the tile in dental stone tools that I have been
advocating.

So, this gets me thinking...   Why not embed chunks of aluminum in dental
stone to make a conforming curved tool?  Will the dental stone securely
bond to the metal?   Will the metal wear away to give good contact with the
glass?   Will the grinding quality be good?

I guess I will put that on the list of future experiments.

. . . Richard

----- Original Message -----
From: 
To: "Peter" ;
; 
Sent: Sunday, December 22, 2002 7:33 AM Subject: Re: ATM Mirror-o-matic -
Aluminum Tools


>
> > Please explain a bit more about the aluminum tool. I'll be hogging out a
> 16"
> > soon (by hand) and I'd like to try an aluminum tool. You mentioned it
> should
> > be made to the desired curvature of the mirror. Can I do this on a lathe
> by
> > simply trimming or beveling the ends? What size should the tool be
> relative
> > to the mirror? Should I do the hogging out with mirror on top or TOT?
>
> The alu. tools that Jack Schmidling made for me where turned on his
> lathe...every inch radius or so of the tool was turned to a different
> height, which approximated the desired curvature in a stepped fashion.  I
> then had to spend some time at 120 (maybe 80, I no longer remember) grit
> to do a decent job of mating the tool to the blank.  (The blank had been
> hogged out previously, or came molded/pregenerated.)  If you are careful,
> you can generate the curve on your slid alu. tool with your lathe at
> home.  (Or mold a dental stone version, and then 'tile' it with 1/4 inch
> aluminum.)
>
> My tools for smaller mirrors were full size (4 1/4, 6, and 10 inch).  For
> my sixteen inch mirror I used a ten inch alu. tool for all grinding (the
> blank came pregenerated).
>
> As for hogging out the mirror, I recommend TOT, but my blanks came molded
> or pregenerated, so I can't commenet with any real experience in this
> matter.  However, for most of my mirrors, from 4 1/4 to 16 inch diameter,
> I did almost all (or 100% in the case of the 16 inch) with TOT...for
> grinding, polishing, and figuring.
>
> Tom Krajci
> Tashkent, Uzbekistan
>
>
>
>

--- BBBS/NT v4.00 MP