New Micrometers

I have some toy money and I am lacking in metric measurement tools.

I have 1/10000” reading mitutoyo 1” and 2” traditional mics and a set of gage blocks ( mics and blocks check out with each other and the mic standard which came with the 2&rdquo

I am considering adding new shiny 25mm mic - especially as I have recently added a metric tool grinder, so it will save a bit of 25.4 calculating.

Do I add the matching old skool mitutoyo, a cheap old skool mic, or go digital - and if so is there good reason to go for a mitutoyo or other make?
I think ideally I might want to also add a depth mic - I use the verynear calliper for depths currently.

Thoughts please.

Dave

I have a Mitutoyo 25mm mike in microns which has the heat shield to reduce the heat from fingers from affecting the reading. Get the type with the heat shield if you can. The micron resolution is not needed, 10 micron is more than enough for 99% of work. I sold my digimatic's as they are not needed enough any more and I can manage imperial and metric mechanical ones. I also have two Mitutoyo imperial depth mikes, one 3" and the other 6" with different length bases. You can get clamp on base extenders for fitting to vernier/digital calipers which might make them more versatile and accurate.

Edited By old mart on 30/11/2021 19:11:17

You don't say how much money is in the pot but there is a vast difference in cost of say Mitutoyo 0-25mm reading to tenths and the same make in a digital version.
Personally I would stay with the traditional mic although digital measuring instruments are very convenient to use.

Emgee

Hi Dave,

Will the metric mic see much use? If so a Mitutoyo, for my old eyes I find digital easier to read. The old micrometers I have are all analogue and I still manage to read them, but it is getting more difficult.

Thor

If you go for Mitutoyo you will not be disappointed, you will also pay top dollar for it, it all depends on how much you are going to use it, personally the older I get the harder it becomes to justify top quality equipment, there just isn’t long enough left to get my money’s worth out of it. I certainly wouldn’t go for a digital one, the ones I have used were heavy and not that reliable although things may have changed in the time since I last used them in the day job.

the pot is £500, but I also want to fix the lathe DRO in that - about to post a seperate thread about those.

Not sure how much the micrometer will get - but inspite of most of my machines being 'native' imperial the mill and lathe have DRO's which are almost always set to metric.

I have 3 sets of verynears, 1 traditional stainless one and a pair of lidl/aldi/soemwhere else cheap digitals. The digitals seem to always have flat batteries - hence wondering about battery powered micrometers...

I do as it happens have an old Mitutoyo 0.001mm digital micrometer head from an optical stage, but that takes 3 AA batteries and is the size of a stepper motor.

Dave

If you go for Mitutoyo, br warned that there are a lot of counterfeit copies out there and I recommend buying from a reputable source even if the price is slightly higher.

I bought a Mitutoyo 0 to 1" tenths reading micrometer with carbide anvils in 1971. Poo Pooed by the older toolmakers as rubbish and a waste of my £4.50. I only took it out of use last year when it was replaced with one from MSC for less than £20. At 73 I will not ever need another imperial micrometer, although my machines are all metric the metric measuring equipment stays in the drawer as all my old motorcycle work tends to be imperial. I find the digital offerings to be bulky and heavy in use to get a good feel.

Any machinery I have is imperial, though the Warco GH1330 has dual dials, so I work in imperial.

I have two or three second hand metric analogue mics acquired over the years, but don't use them much.
I did however buy one of these, albeit not from Chronos; mine came in a sale direct from China, but I was fortunate in that it is one of the higher spec ones, with nicely finished carbide anvils. I've seen reports of mics which look the same, but with a very poor finish on the anvils, so beware.
https://www.chronos.ltd.uk/product/electronic-digital-micrometer/
I note that Chronos correctly differentiate between accuracy and resolution, but is does seem better than the quoted figure.

I find it's accurate, going by imperial gauge block readings, and easy to use, though the overall finish isn't up to high spec models.
Unlike some of the other cheaper digital mics, it has a metal analogue thimble, (in metric) for when the battery goes flat, which it will do.
The main downside is short battery life; my M&W 2-3" one fares much better with that aspect, and an SPI one somewhere between the two. Also I doubt it is coolant/water proof.

The main reason I pick it up, in preference to my usual analogue mic, is either for being able to toggle between units, or for comparative measurements as one can zero it at any size; it saves errors in maths.

Bill

Edited By peak4 on 30/11/2021 20:22:33

Like Chris Evans I bought my first Mitutoyo 0-25 mic to the accompanying sounds of derision from work mates.

What I personally liked was the the friction feel thimble compared to the other makes ratchet type again to derogatory comments on it's usefulness and longevity potential.

Well, I was so impressed by it's performance the 25 to 50mm got added then the two M&W imperial mics were replaced, again to the disdain of unconvinced bystanders. Two uni- mics followed along with a depth gauge - all Mitutoyo, all satin finish, light to hold and easy to use and all conventional readout.

They served me well through my working life and some twenty plus years since right up to date - I was using the 0-25 only today, still as effective as when I bought it and just as accurate.

The humble vernier still has its place when measurement is outside the scope of mics but digi verniers are only used for quick identification of size as machining takes place, never direct final measurement. As an aside a guage block can be used to check a mics readout but not the other way round.

As always it's down to personal choice but I'd have no hesitation in buying them again though I doubt I'd be impressed with their current cost.

Tug

Edited By Ramon Wilson on 30/11/2021 21:39:57

I have digital 25mm/1” mitutoyo which was purchased second hand, years ago. Discarded due to a small chip on one anvil, l think.

It only gets used when I really need precise measurements. So I purchased a 25-50mm/1-2” digi from Arceuro. While not quite in the same league as the mitty, it does a good job (bought for measuring engine parts, mostly), but is now used like the mitty - reserved for precision jobs.

My mitty depth gauge, likewise, is kept safe in the house.

They are all better than my machining skills, but will be more use when I get more practice with the surface grinder.

I now always buy measuring kit which will reliably measure to a tenth of my machining capability.

While they need batteries, they are easier to read than a vernier device - a sure sign of getting old, I think!  Easy to measure in either metric or imperial, too.

Edited By not done it yet on 30/11/2021 22:12:53

It has to be a digital mic, surely.

• It facilitates working in either imperial or metric - or both. No need for two mics or maths.
• You can dial up a measurement in one system, press a button, and you've instantly got its equivalent in t'other system.
• You can dial up a desired dimension, press zero, measure the work, and you've got the deviation from the desired end-point.
• Because you can zero the thing at will, you can measure dimensional differences directly, or steps, etc.
• It's easier to read, so less error-prone.

If bought with a reputable brand name, there's a good chance of sensible warranty and after-sales service. And a quality-control certificate that actually means something...

I realise we all do different model engineering but the talk of measuring to 1/100000" and buying micrometers with heat shield to stop finger temperature affecting the reading is mind blowing. I doubt many engineering companies work to these tolerances.

Unless we are working in temperature controlled workshops to a very specific temperature band its almost certainly accuracy beyond our needs!

I mainly use digital devices not for the accuracy but for the clarity of the displays; my eyes don't work well enough for the vernier scales...

Having tools that are capable of measuring to 1 micron and actually measureing to 1 micron are two very different things. (I used to work in a metrology research company)
If you look at the typical spec sheets for mitutoyo mics then they might have a 1 micron resolution, but they have an accuracy of +-2 microns...
Only the *really* expensive ones are any better.

I am under no illusion that I will actually be able to measure to a micron, but the old metroloy adage is to have tools that are at least 10x more capable than the accuracy you want.
So for 0.01mm you really want a 0.001mm tool.
Thats why I originally bought 1/10000" micrometers.

Just occasionally when I hold my tongue just so I manage to hit the number I was after dead on.
That feeling when a bearing slides into a bore with no shake, or the piston makes a bouncy airtight seal is great, and even more so when you did it to measurements rather than sneak up on it fits.

Dave

I've worked in some very high end toolmaking places where we chased the tenths to achieve maybe half a thou overall at best. Only one place was temperature controlled. we all had "Tessa" and "Shardlow" micrometers but day to day standard Mitutoyo stuff was good enough. To this day I prefer to read an imperial depth micrometer rather than a metric one.

Can't really add too much other than to say that due to battery problems in the main, I always use manual reading equipment - micrometers & calipers.

It's worth remembering as well that shops do not know the difference between ,eg, SR41 & LR41 cells (I think those designations are correct). One of my two electronic calipers specifies SR41 which are Silver Oxide and a slightly higher voltage than the supposedly equivalent LR41. The device will work with an LR41 initially, but because of the voltage difference, and I believe the discharge characteristick, will soon fail. Once I realised the difference between the cells, I ended up having a row with one shop who tried to sell me the LR41 saying it was an equivalent to the SR41 which it may be for some equipment, but definitely not for my calipers.

Another problem maybe cold weather - mine seem to give up all too readily in the cold. Unless, of course, it's me giving up because of the cold!

As far as eye problems go, I have no compunction in using a magnifying glass, or a set of clip-on magnifying lenses, or even both simultaneously.

Regards, (is that an unfortunate pun given the subject matter?)

Peter G. Shaw

Currently building a model that has imperial measurements, how I hate imperial fractions, and I was short of a 1” to 2” micrometer so I looked on line for reasonable quality/reasonable price and found a good range at “Allendale”, can’t remember how much I paid but it was very reasonable for the quality. When I came to use it I found that instead of the ratchet being operated by the small thimble at the end of the spindle, the ratchet was operated by the the large knurled barrel on the spindle, it takes some getting used to when every other micrometer that I have used is via the small thimble. Their products are well worth considering. Dave W

Same as me, once into 'tenths' territory we used slip gauges & comparators.

Tony

you are right there. me i work in a air conditioned temperature controlled clean room with calibrated equipment. we rarely work to those limits