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[98vtec]

So ive been learning a few things and one thing i finally got to learn was how to read one of these sum bitches.  Short and sweet here we go..

Take your micrometer and whatever you are measuring and move the dial until the two ends of the mic are snug with the object.



I chose to use a yuengling bottle i just finished.


Now is the tricky part.  The more you hold the mic, the hotter it is going to get and the more screwed your readings are going to get.  So be as fast and as accurate as possible.  Typically, in our situations, the part we are measuring will be round so you cant exactly have two flat pieces of the mic sit flat with a round surface.  Key here is to make sure that the middle of the flat pieces (anvil and spindle) are sitting on the round object on both sides.  You will have achieved this if you have an even gap all the way around the anvil and spindle end piece and the round thing you are measuring. 

You want to be able to slide the mic off without force, but not so easily to where the mic is sloppy.  It needs to be snug.  Lock the mic and pull it off.

Now how do you read what you got?




This is a 2-3" mic so all your readings will be from 2.0001 to 3.0001

The horizontal "ruler" (sleeve) is X.  2.X001.  Each dash mark represent .25.

The numbers on the thimble (the thing that spins) are 2.0XX1. 

As you can see, the line on the sleeve is between 12 and 13 and the thimble is lined up beyond the 3.  So as of right now, our number is 2.3XXX.  Each small line is .25 so add .25 and .12 and you get .37 and the next two numbers in the measurement, 2.337X

For the last number in the measurement, look at the last picture.  You want to find the line that matches best with the other and that will be your last number.  in this case it is 5 and gives us a final measurement of the yuengling bottle of 2.3375"

beer ftw

[d112crzy]

Good post. I've never been able to get consistent readings when using them bitches. Same thing with the calipers.

[98vtec]

from what my buddy max is telling me, it just takes time and experience to get the feel for it and be able to do it quick before the mic heats up and fucks your mom.

[d112crzy]

Damn. What kind of metal are they made out of that they expand in such a short amount of time and with such a slight change in temp?

[snm95ls]

Damn. What kind of metal are they made out of that they expand in such a short amount of time and with such a slight change in temp?

All metals expand pretty quickly when you are talking about a change of a tenth of a thousand of an inch.

There are many outside micrometers out there with thermal insulating pads on the frame to reduce the amount of heat introduced error.

EDIT:  Actually the one pictured has what looks to be a small pad on the frame.

[98vtec]

pretty sure its steel but still, you are picking something up that is at room temperature (if you are inside and not in a garage) and your hands are 90ish degrees.  Just think how little time it takes the thermometer you put in your mouth to react?  pretty quick eh?

If you are working outside in 65* weather and counter it with warm hands, it going to heat pretty quickly through conduction.  I guess the other way to counter this heating is to wear gloves.

[98vtec]

mine are standard so thats all i have to work with

[patsmx5]

Wearing gloves is standard practice when doing critically toleranced shit. Mitutoyo = Badass mike.

[Travis]

Mitutoyo = Badass mike.

Ha, speaking of that company, 2 close friends of mine are blind brothers, and just got a bunch of the talking equipment, that shit is fucking wild.

[CRX304]

rule of thumb... hold the tangent of the radius w/ only ur pinkey finger and palm... and scroll the dial till it snugs the object w/ ur thumb and forefinger.

back off and resnug, back off and resnug... measure 3 times

Dr. Mike

[Logan76]

I read mic's inside and outside and depth on a daily basis, and I would say inside is the hardest to get a good feel with, you almost need to hold the anvil still and move your mic back and fourth on a round surface, while adjusting it, to get a good feel and size of whatever your mic'ing, moving it lets you find the apex of the circle and lets you get your widest part, youll feel the friction of the mic touching and then moving away from the object, then you finally find the highest point and thats your size, I personally use Starret, but I have a few Mitutoyo calipers. Also I suck at explaining things. Nice write up man.

[jlude90]

should it also be mentioned not to he-man tightening the thimble down?

are yours ratchet stop blake?