Re: [ATM] how to fix a zone and understanding small tool action

["Bob May" <rmay@nethere.com>]

Often people get confused as to what the test is telling them.
In the Ronchi test, if the lines tend to stay towards the
distance that they are in the center, it means that the zone is
high as the ROC is near the center zone which should be the
shortest zone.
What you need to do is figure woult exactly what the shape of the
surface is and go from there.
I'l note that the small lap like what you have done will need to
be used carefully as it is easy to get into holes in the surface
which need to be removed with the large lap over the whole area -
basically you have to take down all of the surface by what you
have dug that little ridge to and then go from there.  I'll also
note that it seems that the really subdiameter pitch laps tend to
be used with much longer strokes than what is really needed.
In the end, I'll bet that the ring that you had is really a
depressed zone as others have mentioned and you've just been
making it worse.
Bob May

rmay at nethere.com
http: slash /nav.to slash bobmay
http: slash /bobmay dot astronomy.net


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