Re: Kilian's Mirror: Poor testing resul
PFAFF2@delphi.com
Mon, 17 Apr 1995 23:27:42 -0500 (EST)
>
> >Oh, I also took a dial micrometer which is a thing that looks like a
> >speedometer with a straight shaft sticking out of one end, and if you
> >push on this shaft, the dial measures displacements to 0.001 Inch.
>
> >OK, now I have a question. I think that my knife edge and slits are quite
> >poor. They are single edge razor blades, and look rough under a ten-power
> >loupe. I am thinking of making some brass ones like Texereau suggests.
> >
> >
> > -Alan Kilian
> >
> The dial indicator is a good idea, although I don't recommend setting it
> to "0" at the center zone. The problem is that you will get to know what
> the numbers should be and may be tempted to "adjust" your readings. I've
> been there.
>
> The knife edge doesn't need to be sharp. Lap the razor on a stone or
> with fine grit on a piece of glass until the edge is straight.
>
> I use a slitless tester and recommend it.
>
> Peter
>
>
>
> --
> >
>
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>
I like to use the second zone from the center as my reference point.
The center zone is very difficult for me to get a good reading and
I do not want base my critical outer zones on this poor center reading.
The center zone has a large tolerance as compared to the outer zones.
Bob Pfaff