Lapping rod ends
 

Does anyone know how to lap the end surface of a rod so that it is perfectly
flat and normal to the rod axis?

I thought I had an article by Geometer on how to do this but I cannot locate
it. It is no longer available on Yahoo Hints & Tips. If anyone has this
article 119/2961 please let me know.

Thanks, John.

In article ,
"John Wilson" wrote:

Does anyone know how to lap the end surface of a rod so that it is perfectly
flat and normal to the rod axis?

I thought I had an article by Geometer on how to do this but I cannot locate
it. It is no longer available on Yahoo Hints & Tips. If anyone has this
article 119/2961 please let me know.

Thanks, John.

We used to lap the ends of laser rods with a collet chuck that grabbed
the rod, which had a large flat face to keep it aligned on the lapping
film. I guess the chuck face got lapped a bit along with the rod-end. I
can envision a design to avoid that, but it makes the whole business
much larger. - basically expand the face so that face can ride on a
non-abrasive surface which is parallel to the surface with lapping film
on it.

It would be pretty straightforward to make such a chuck on a lathe. I'm
pretty sure they can be bought, too, since we did not make the one we
used. It was 15 years or so ago, so I could not tell you who made it,
offhand.

--
Cats, Coffee, Chocolate...vices to live by

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


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

"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

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
(remove wallet to reply)

In article , Harold & Susan Vordos says...

Wouldn't you say it's a matter of what you'd call *perfect*?

Now Harold, sure that's right.

He knows what he thinks, when he says 'perfect.' That
may not be what I think of when I say the same word.

This is why tolerances are put on dimensions.

He didn't put any tolerances there, so I felt free
to add in my own interpretation. "Perfect" means
no deviation from the correct geometry, at all.

Imagine a machine tool, with absolutely *no* rust
on it all....

:^)

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

Wouldn't you say it's a matter of what you'd call *perfect*?

Now Harold, sure that's right.

He knows what he thinks, when he says 'perfect.' That
may not be what I think of when I say the same word.

This is why tolerances are put on dimensions.

He didn't put any tolerances there, so I felt free
to add in my own interpretation. "Perfect" means
no deviation from the correct geometry, at all.

Imagine a machine tool, with absolutely *no* rust
on it all....

:^)

Jim

Now that you put it that way, I understand! g

H

"Harold & Susan Vordos" wrote in message
...

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

Wouldn't you say it's a matter of what you'd call *perfect*?

Now Harold, sure that's right.

He knows what he thinks, when he says 'perfect.' That
may not be what I think of when I say the same word.

This is why tolerances are put on dimensions.

He didn't put any tolerances there, so I felt free
to add in my own interpretation. "Perfect" means
no deviation from the correct geometry, at all.

Imagine a machine tool, with absolutely *no* rust
on it all....

:^)

Jim

Now that you put it that way, I understand! g

H

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Thanks for the comments and I did receive a copy of Geometer's file. I
shall be a little more careful of the use of 'perfect' in the future.

John.

I can't believe no one has asked this yet.

What procedure and equipment did you use?

Adam Smith
Midland, ON



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
(remove wallet to reply)