Micrometer Blues

Good evening everyone, after some advice please.

x

I find this quite difficult to read, as the fiducial line is inside the thimble. This presently reads 7.50 mm, but the 0.5 line is obscured by the thimble sleeve. It can be quite confusing particularly at intermediate settings.

So is it possible to move the thimble about 0.2 mm to the right on the spindle? How is the spindle held in the RHS of the thimble?

How many heart attacks would I be responsible for if I took the angle grinder and took 0.2 mm off the left end (scale end) of the thimble, heretic that I am?

Thanks as ever in anticipation of The Knowledge!

Simon

Looks perfectly normal and correct to me. If you really hate it, get a digital one.

Hi Simon

With your picture viewed full size in your album it is clearly seen reading as 7.50mm, don't forget you only see halve of the line width. I sometimes have to turn the thimble a bit to check exactly before turning back to the measured position.

Emgee

I can just see the line peeking out from under the thimble. You might try disassembling the mike to see if the graduated skeeve can be slid toward the frame. On some mikes the sleeve is just a friction fit. It might also be possible to stone off the end of the sleeve to allow it to slide to the left (according to the picture). I like the Brown and Sharpe mikes with the slant line graduations.

Hi Simon it is possible that the sleeve has worked is way to the right and using the adjustment C spanner rotate it and pull further to the right clean the gap then twist and push it back and adjust and calibrate to check size. It is tight fitting sleeve but only use the correct spanner.

David

Looks perfectly normal to me too, you can see daylight after the 7mm mark, so it's obviously not 7.0mm. Having said that, I hate metric mics, I've lost count of the number of times I've made something exactly 0.5mm wrong. Eventually you'll get used to it. I''ve bought a digital mic, but I hardly ever use it.

Hi Simon,

While i have to agree with the other replies in regards to it reading correctly i i also understand where you are coming from !

Take a look at the youtube channel mrpete222 Shop tips #302 he stripped down a mic and lightly skimmed the end of the barrel opposite the thimble so more of the line was showing as he had troubles seeing it when most of the line was under the thimble .

Ian

If it makes it easier for you, just skim the barrel.

I agree with others, this is normal. I have found over the years that it takes practice and a basic knowledge of how the things work to use instruments consistently, just keep using it and thinking about the reading until it becomes second nature.

Hi Simon,

MrPete222 on YouTube has a video on rectifying this issue here... **LINK**

[Edit: Sorry Ian seems to have beaten me to it.]

HTH

Jon

Edited By Jon Gibbs on 13/04/2017 08:35:25

Go back to IMPERIAL, You don't get the same problem!
BobH

Looks spot on to me.

Send it to me and I will replace it with something which would be easier for you to read. I think I may have something that reads to the nearest 0.1mm with an accuracy of about one digit.

As there appears to be only one reading among so many that troubles you, I think there is no reason whatsoever to consider potentially destroying such a precision device. Live with it and learn how to use it, is my advice. You clearly know where the 7.50 reading occurs, so what is the real problem?

If you can find one at a decent price the Mitutoyo Combimike is worth a punt, the white numbers on a black background are very clear, variants were available with an imperial spindle combined with a metric mechanical digital readout and vice-versa. Mitutoyo also did all metric and all imperial spindle/mechanical digital combination micrometers, other brands did them too.

I have had mikes worse than this but it is annoying, skimming the barrel end is about the best option if it bothers you that much.

Tony

.........So, if I have got the gist of this, you want to make an accurate micrometer 'inaccurate' in the interests of increased accuracy...(?)

The gist is that the OP wants to see more of the spindle lines, no mods suggested will affect the 'accuracy' of the micrometer.

Tony

If you shorten the thimble to make the line more visible you have built in an inaccuracy becasue the line placing will no longer by true (accurate)...especially with the OP's main problem of "intermediate settings"

.....unless the OP is planning to measure exactly how much he is going to remove from the thimble and then adds this number to any measurements he makes in future (to 'correct' the measurement and keep things 'accurate'

... 'How many heart attacks would I be responsible for if I took the angle grinder and took 0.2 mm off the left end (scale end) of the thimble, heretic that I am'?

​I guess you're speaking metaphorically... If you think can take off 0.2 mm with an angle grinder you're a better man than I am Gunga Din, steer well clear of any 'adjustment', get a loupe or magnifier to view the line better, or better still get a digi mic, ( Mitutoyo if you can afford it )... leave well alone it's fine as it is.

​George.

+1

Few people seem to understand how a micrometer works.

Jon