View Full Version : Micrometer ratchet preasure

loose nut
01-03-2011, 04:22 PM
I have always turned the spindle on a mic, when closing the spindle to take a measurement, until I get one click on the ratchet. After watching the Darrell Holland vids he says to use two clicks.

Does it matter.

Once the ratchet starts clicking doesn't that mean that it is now slipping and isn't putting anymore pressure on the spindle.

01-03-2011, 04:45 PM
I think it might add a little more on the second click, depending partly on how strong the ratcheting spring is and how fast you do it. I would answer the question for my own individual case by taking the micrometer and closing it both ways a number of times. Whichever way gets you the closest to zero the most times wins.

01-03-2011, 04:58 PM
I like Chevys and shell oil better..:)

01-03-2011, 05:08 PM
when I use the ratchet of a mic I close the spindle on the work and then move the mic slightly side to side as I turn the ratchet through a 1/2 to full turn. That is to be sure the mic is squared up on the shaft or part I am measuring. It is very easy to have the mic out of square and get a false reading. No matter how many times you spin the ratchet knob it won't get any tighter after the first few clicks.

I don't think one or two carefully managed clicks is adequate to get a good reading, at least in my experience having tried that and many other ways. Many times I use the ratchet and then a manual feel on the spindle and over the years have found my use of the ratchet gives the same reading as a manual feel on the spindle.

People get to anal about stuff like this but you have to develop a soft feel when using measuring instruments.

01-03-2011, 05:41 PM
Zero the micrometer by closing fully, and practice to get the feel needed to get a consistant repeat zero reading. If a couple of gage blocks or other parts with known dimensions are available practice measuring them until consistant results are achieved. The feel and consistancy comes from practice and use, not counting clicks or other "expert" advice you might get on the internet.

01-03-2011, 07:07 PM
Clicks ... SCHMicks
Just go by 'feel'. :)

01-03-2011, 08:09 PM
If you can get consistent repeatable results with one click, don't worry about it. You're doing fine. What JCHannum said: practice and experience.

01-03-2011, 08:58 PM
You will get your feel, zero it out and practice. I kind of like friction clutches, but the "roll the part" and check/recheck is key.

One hint for measuring. When working parts that are parallel or milled, use a gauge block to check the mic. When measuring diameters, use a gauge pin (very accurate type that has been calibrated - not a plain + or - set type, I have the deltronics for mic checking) to zero check your mic.