Harold & Susan Vordos wrote:
"jim rozen" wrote in message
...

In article , John Wilson

says...

Does anyone know how to lap the end surface of a rod so that it is

perfectly

flat and normal to the rod axis?

That's not possible. Any technique you use to form the end of the
rod will render it less than perfectly flat, and less than
perfectly normal to the axis.

Jim


Hey Jim,

Wouldn't you say it's a matter of what you'd call *perfect*? Starrett has
been doing it for years, lapping micrometer spindles and anvils. They can
easily resolve .000050" in the hands of someone skilled, so they must be
pretty close.

Harold


Place I used to work at, Hemco Gage, had a Pratt & Whitney SuperMic. I
lapped the ends quite often, to .000010 parallel, as indicated by the
Mikrocator indicator and a class XXX gage pin.

--
Steve Walker
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