> Date: Thu, 7 May 92 14:44:04 -0700
> From: berry@hawking.pei.com (Berry Kercheval)
> To: Captain Capsaicine <sfisher@wsl.dec.com>
> Cc: british-cars@hoosier.utah.edu
> Subject: Re: RE>deck the block on Scotts
> Captain> ... in the days of the
> Captain> T Series recommended smearing the top of the block with valve lapping
> Captain> compound, dropping the head on it, and carefully moving it in smooth
> Captain> circles so that you got the two surfaces perfectly flat with respect
> Captain> to one another. Then you don't use ANY gasket.
>
> One trouble with this, as I rememeber from my telescope-making days, is
> that you DON'T get a flat surface this way, you get a spherical one.
> That's how you make a spherical telescope mirror -- grinding the
> mirror blank against a "tool", usually another piece of glass.
>
Funny, this very thought came to my mind when I read Scott's
description. However, with lens grinding you walk around the tool as
you grind to get a spherical surface; but your point is correct, you
don't end up with a flat surface. Oh well, I guess if the curves fit
together, maybe it really doesn't matter.
|