On 2018-01-30, Bob La Londe wrote:
I must be getting old. I usedta never was sentimental about things.

Anyway, yesterday I went through all my micrometers and the ones that
measured the most accurately and consistently using gage blocks and the
few Starret standards I have were the Starretts. Those all came from my

[ ... ]

In those from my grandfather there were two marked JT Slocomb. They
actually checked pretty close on the line and over their range, but they
were both quite stiff. I wonder if it would be ok to soaked them in
acetone to get any gunk out of them.

It should be a start, followed by instrument oil (Starrett makes
a good one).

Next were my modern El Cheapo Chinese micrometers. I've only actually
bought one.

[ ... ]

All of them. One set of Speedways that came out of a
pile of salvage from an old house were all as good as I could expect for
cheap imports.

O.K.

Last, and the other set I had hoped would be good were a set of four
Companion D.J. 0-4 inch. My dad told me they were cheap when he gave
them to me, but atleast I didn't have to engrave them. They all were
already marked with R. La Londe. (his name and mine) The 0-1" was dead
on when I checked it with a gage block, but the standard that came with
it was about a half thou off. Two of the others measured consistently
but where off. One by .00016 and the other by .004. The biggest one I
couldn't get a consistent measurement out of to save my life, and it was
very stiff. When I rolled the barrel out I could see it was full of
some old sticky gunk. Again... I wonder if I can soak it in some
acetone.

Sure -- again follow by an instrument oil in the threads.

I'd like to adjust the other two, but I don't see how. They
do not adjust the same way as any of my other micrometers, and the case
doesn't have any kind of tool or even a slot for one.

O.K. I've never seen a "Companion D.J.", but aside from the
common rotating sleeve to zero many micrometers, I've seen at least two
other systems.

1) Short sleeve on the thimble. (You would probably have noticed
this yourself.)

2) The thimble attaches to the spindle by a cone, held by the
small diameter spinner. If it does not have a ratcheting
spinner, there should be a small hex at the base. Loosen the
spinner a turn or two, tap on the end of the spinner with brass
or a hard plastic, and then loosen the spinner once the thimble
moves.

Then with your fingers on the cone, close the spindle until it
bottoms and your fingers start to slip. (Using light pressure).
Lock the spindle, lube the cone with instrument oil, and slide
it back together, turn until the index zeros, and then screw
back in the spinner.

2a) If it has a ratcheting spinner, you may see a small cross hole
which will let you use some spring wire as a wrench, or you may
have to remove the screw which holds the ratchet in place, and
then gain access to the hex base or to a cross-hole wrench hole.

Of course, there may be some other system yet. It would help if
I could see the micrometer, instead of trying to guess. :-)

Interestingly every single 0-1" I have was good. No matter the brand or
where it came from.

Sounds good.

Enjoy,
DoN.

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