What is this knob on the calipers for?

It's for locking the bezel, when zeroing it. Standard thing on dial gauges.

Leon

Hi Ted,

The bezel can be rotated when the bottom screw is loosened. The dial rotates with the bezel and "zero" setting is accomplished accordingly.

Bob Swinney

Ted S wrote: (Snip)

You are right. Loosen the bottom knurled screw and rotate the bezel around the crystal. Tighten the screw and your new zero setting stays put.

(Snip)

I would say you got a good deal. Your calipers look almost exactly like the commodity Far East brands I use. I expect that 'Aerospace' is a brand du jour.

I suggest you check them on all surfaces of a clean 1-2-3 block. If they read reasonably close to the proper value, you did real good.

Please store them somewhat 'open'. Closing completely invites wicking. Before each measurement, close the jaws lightly on a piece of clean cotton and draw the cotton out. This removes grit, improving accuracy.

--Winston

Like everyone else says... you can change the dial setting and lock it down.

This is the same thing I got from Enco a year ago for about $15 on sale. Still, $5 is fine. I use mine regularly without problem.

-Bruno

May I offer a word of advice? Get in the habit of keeping the calipers closed at al times except when actually making a measurement. The rack teeth are very fine and VERY prone to picking up bits of swarf which will make the gears jump the needle. Usually when the needle gets jumped from the straight up position as shown in the photo there is a way of returning it to that straight up position. But if you don't have the little tool to do that you may have to get used to using the caliper with the needle pointing in who knows what direction.

Errol Groff Instructor, Machine Tool Department H.H. Ellis Tech

860 774 8511 x1811

Much better done with a piece of clean paper, which won't leave behind bits of cotton to interfere with zeroing the device. It's the best way to clean the spindle and anvil of a 1" micrometer, too.

Harold

The advantage of cloth is that most of us have the cloth handy. I have always used the button placket of my shirt before measuring with either calipers or micrometers. I check for debris by checking zero; if it is off, I clean again or blow any lint out. If I recall correctly, I was taught this by my grandfather.

-- --Pete "Peter W. Meek"

The advantage of paper is that it is held to strict flatness, so you can close the device on the paper such that when you withdraw the paper, it will wipe the anvil and spindle PERFECTLY clean so long as you pull on the paper, not push. . Most of us usually have a scratch pad near when machining, so paper is usually readily available. I've used both methods and no longer rely on the cloth. It just doesn't work the same way. You may notice that a micrometer cleaned with cloth will still yield a noticeable sign of dirt when immediately followed up with a cleaning with paper. Once through with paper will always yield perfectly clean faces. Give it a go. There is never a need for a second try.

Harold

IRRC.. "Aerospace" is a house brand of Peacock. Not bad stuff at all. Chinese.

Gunner

That rifle hanging on the wall of the working-class flat or labourer's cottage is the symbol of democracy. It is our job to see that it stays there. - George Orwell

I heard somewhere that when you're storing your calipers and mics it's a good practice to leave them open slightly. Something about eliminating strain on them I think. I don't imagine there would be much strain on them unless you really put a lot of force into closing them, and in the case of the calipers tightening the set screw. Anyone else heard this? (sorry for dragging up an old topic - I haven't caught up in a *long* time)

chem

Errol Groff wrote in news: snipped-for-privacy@4ax.com:

On Fri, 16 Jul 2004 02:45:00 GMT, Jim K calmly ranted:

I learned to wipe them down and leave them open slightly (0.015-0.030") to prevent any finger acids or moisture from causing damage to the measuring surfaces. This info came from a 40-year QA inspector back when I was in that field, but I vaguely remember my 8th-grade metal shop teacher saying something similar back in the 60's.

I've always done that and have never had a problem.

- DANCING: The vertical frustration of a horizontal desire.

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