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Quote "Any secret to this, or tips anyone can give me?"

It help using a mike stand. Do not need a fancy one a home made will do.
My mike stand uses a segment of breake rotor for a base.
 
Agreed. Except the 3€ plastic ones I use to check the size of screws.

Well a plastic caliper does not belong around a machine. I have a Swiss Made Plastic Dial caliper, reads in 0.1mm. is 40 years old and is OK. I used it at work to measure size of electronic components, not a critical operation.
Now sits next to the scews bins rack.
 
FWIW,
I've used and own everything from dirt cheap 4" and 6" digital calipers that were given to me as a "gift" for renewing a couple of subscriptions, to Mitutoyo dial and solar powered digital calipers. Due to the built in slop, grinding powder and whatever else is binding up those free calipers, I wouldn't even trust them for woodworking levels of accuracy. All calipers and for sure digital's certainly aren't equal in my experience. No doubt there are other digital calipers just as good as Mitutoyo's or possibly even a bit better that are or would be more common in other parts of the world. But on forums where most of the members are American or at least North American and professional machinists like Practical Machinist, Mitutoyo digital calipers are generally the caliper of choice, and are judged about as good as you can expect. But you also need very consistent technique to get decent accuracy from any set of calipers no matter who makes them. There are some lesser known European brands that are supposed to be very good, but I have zero hands on experience with them.

That thumbwheel on most calipers isn't what you use while closing them on a part, it's designed to be used for larger movements, your supposed to either close the jaws between your fingers or both hands with larger measurements. And you use that consistent feel or method every single time. While most good calipers are only rated at generally + - a couple of thou. High quality calipers should at least make repeatable measurements to quite low tollerance levels. The actual measurement reading may be off that +- .002, but those readings should at least be repeatable to well under .0005 if the user does his part. I can say that while most well respected manufacturer's state there calipers are only accurate to that + - .002 level, mine are well under that with any gauge block I've tested them with so far. That +- .002 number is a maximum allowable tollerance and certainly not the average. Mine so far will do under .001. But all of this is only true for almost brand new equipment. And I still really only trust calipers to that + - .002 level.

But if you start to look around, you'll also see that many calipers and especially the digital ones today don't have those inside jaws for measuring bores. That's because the design of those calipers that have those inside jaws just isn't very accurate, and the smaller the bore the less accurate they are. There's usually a narrow flat ground on each jaw. So your not using point contact to measure bores. And on a lot of calipers, the distance between those inside jaws faces doesn't agree with the distance between the outside jaw faces, so even that measurement isn't all that accurate. But those inside jaws can still be used for something like measuring slots, you do need to cheat and just set the calipers to the slot size, lock that setting and then measure over the jaws with a good micrometer. But your then using the calipers much like a gauge and using other methods to obtain an accurate measurement.

Obviously all this equipment wasn't even available at one time, yet fairly high precision parts were still done using probably not much more than yardsticks or shop built gauges, and the old school inside and outside slip joint calipers that can't give you an actual measurement of anything. Or they used feel and comparing one part against another one. For example the piston fit to the bore. It was probably and mostly due to developing interchangeable threads and parts fit that drove the requirements for accurate measuring equipment. And while I wouldn't want to, I'd bet most engines shown on this forum could be built using nothing more than those slip joint inside and outside calipers and a good 6" or 12" scale along with a very experienced touch. The part sizes wouldn't be exact to micrometer levels, but the engine should still operate just as well.

Your thoughts may differ, but in my shop and for how I work, calipers are by a large margin the most used tool anytime I'm in my shop. For that reason I bought a cheaper but still fairly accurate set of off shore $40.00 calipers for the rough work, and a set of those 6" Mitutoyo solar powered digital's. I can say those Mit. calipers are the very best I've ever used so far. I also own a 6"and 12" set of Mitutoyo dial calipers, but I still very much prefer the digital's for there very fine feel while measuring. But they cost enough that I make a real effort to keep them away from any dirt or swarf, and I make sure they don't get placed anywhere they could be damaged or dropped. But that's just good shop practice, and any good equipment should be treated the same. But even with parts that require measurement's to micrometer accuracy, I'm still using calipers to get me close before I do start using the mikes. So if the tool is going to be used that much and depended on to give accurate readings? Then I think you have no choice but to buy a good set.

Due to that interchangeable parts requirement in industry, they are required in some company's to test and recalibrate there metrology equipment to very very tight levels, and sometimes to do so multiple times per year. At the hobby level and for our own parts were obviously under no need to do the same. But just to reduce the mistakes and the need to remember any fudge factors, it's nice if all our equipment at least agrees with each other for measurement. The actual measurements certainly don't need to meet NIST levels. But I think having them adjusted to read the same, or at least knowing for sure there are inaccuracy's is very important. So buying a set of cheaper gauge blocks as someone already mentioned is a very good idea. And the more you use gauge blocks, the more uses you find for them. I certainly wouldn't want to be without mine. You just use them as your reference standard, and everything gets calibrated to those standards. YMMV, but this sure seems to work very well for me.

Most builds here probably don't need even caliper accuracy levels for a lot of the parts. Yet there are some items that do need everything you can afford for tooling. Checking straightness, lobe lift and position on something like an I.C. cam does need a bit more than the very cheapest tool you can find. Buying measuring equipment at the cheapest possible price can end up being very costly at times. I've got a 1924 edition of a book about building proper master gauges used in industry. Those master gauges were to be used to test the everyday gauges. They talk about setting those master gauges on a lathes faceplate for drilling boring and precision grinding to 5 decimal places back in 1924 using a shop built Dial Test Indicator and shop built hardened and ground machinist buttons. And while I've got the equipment to measure just how far I'd be out from replicating those 1924 efforts, I really doubt my machine tools or my skills could do as well as they managed almost 90 years ago.

My apology's, it seems I went a bit OT to your questions about calipers. :hDe:

Pete
 
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With using Tele gauges the trick I was taught in the air force was to take 4 0r 5 measurements and then average out the readings which will be reasonably accurate. ( you can normally get a reading that is accurate to 0.0005" or 1/2 a thousandth of an inch which is close enough for most work.
The hard part is when you are measuring a deep bore and trying to see if the bore is either parallel or tapered depending on the final result that you require.
I still have my Mitutoyo Micrometers and Verniers etc that are 30 years old and as good as the day that I bought them.
My eyes aren't as good as they used to be and sometimes I find a head magnifier really usefull for taking readings and checking surface finish and assembly of small components.

Hi GoldFlash,

Gus is about to move into the same category of elderly citizen eye sight in about 40 days ,Gus will be 70.
Reading vernier is a struggle. Need very good lighting. Fortunately I can still read Mikes but reading glass now not required at close range.

TokyuHands,Osaka,Japan.
Just Bought a cheapy China made "Dremel lookalike" but comes in a good looking case and an array of min grinding tools. See foto.The finished quality looks good. Cost me 6,000 Japanese Yen. Cheaper than Dremel. Hope it will last. Will use this "Dremel" to mark all the CTC Gear Cutters and future bought cutters.Weather fine but bit hot.

IMG_2023.jpg


IMG_2024.jpg
 
When I did my apprenticeship the "sequence of accuracy" was (partly tongue in cheek, to make the point)
1/ Piece of string with knots in
2/ Wooden rule
3/ Steel Rule
4/ Vernier caliper
5/ Micrometer

The rule of thumb was that checking was always done with the next highest in the sequence of accuracy, that a feature was generated with. So, if a part was made using a piece of string with knots in, it was a waste of time using a micrometer to check it. The logical checking instrument, in this case would be a wooden rule.
I have a Mitutoyo vernier caliper that I use for 95% of my measuring, especially when roughing to slightly oversize.
I use a 0-25mm Moore & Wright micrometer which gets used for anything in the range, when accuracy is required, within 0.005mm anyway. A Starret 25-50mm for that range.
A Verdict 0.001mm DTI for accurate set ups, an assortment of cheap dial indicators for other stuff.
Don't neglect the value of a good steel rule......
I won't use anything with a battery in, because batteries are always flat when you need them
Have a look at Long Island Indicator for opinions about especially indicators, but measuring stuff in general. It's very worthwhile.
best of luck, cheers
Bill
 
I won't use anything with a battery in, because batteries are always flat when you need them

Funny you should say that Bill. Yesterday I bought a Mitutoyo 150mm digital (ie battery) vernier. I currently use a Mit dial vernier which I love, but I on a couple of occasions I have misread it. Don't ask me how- I guess I was being careless. Anyway, no chance of misinterpreting a digital display.

Chris

P.S. keep a spare battery. :)
 
I use a 0-25mm Moore & Wright micrometer

I have one of these too.... actually, had.

I dropped it from standing height onto the concrete floor of my workshop a few months ago. I almost cried.
It has been sitting unused ever since, just can't bring myself to the point of throwing it out.
 
I have one of these too.... actually, had.

I dropped it from standing height onto the concrete floor of my workshop a few months ago. I almost cried.
It has been sitting unused ever since, just can't bring myself to the point of throwing it out.
Before you consider throwing it out, look it over carefully, it may not be as damaged as you think. The barrel and thimble can be adjusted easily.

Paul.
 
The problem I have with telescoping guages is in measuring the guage after I have guaged the hole. Hard to manipulate the guage and the mic, and get repeatable readings off the guage. Any secret to this, or tips anyone can give me?

Use ball gauges rather than tele's on anything under about half an inch diameter. Much easier to deal with, better feel, ergo more accurate result. I never use a tele if I can get a ball gauge to do the job.
 
[QUOTE Anyway, no chance of misinterpreting a digital display.

Chris

P.S. keep a spare battery. :)[/QUOTE]
Unless you are dyslexic, which I am. I am much more likely to misread a digital readout than a dial.

Bill
 
Probably start a firestorm here, but I don't mean to. I must be seriously repressed because not only do I not like anything in the workshop with batteries, but I can't stand dial calipers. I much prefer plain old fashioned direct reading type instruments, even with my aging eyes. Since this is a hobby and time isn't an issue, if I'm in any doubt about a measurement it gets checked
I scored a soon to be scrapped Mitutoyo dial caliper from work. It stays in my model (aeroplane) box for flying field measurements.
cheers
Bill
 
I do not like battery powered products either, not only in the shop but enywhere. There are good reasons:

The Battery in consumer products are always grossly inadequate for economy, size and/or weight reasons.
Batteries have a finite number of full charge/discharge cycles. The life cycles increase as the discharge (capacity removed) gets shallower.
A big battery not only last longer between recharges but if used at moderate discharge it will give more usefil cycles.
The designers of consumer products are not concerned with life functionality, they give you a light, inexpensive product that out of the box appears to be adequate. The battery will soon peter out because is inadequte for the application.

Batteries suffer deeply if discharged below the minimum voltage, a good design would include a sensor that disconnects the battery when is discharged, but such a swich requires expensive MOSFET. Overdiscahrge the battery twice and it toasted.

Some design have the electronic that can not work with a wide tolerance voltage and quit working before the battery is fully discharged, robbing the user of operating time. (Usually non rechargeable batteries).

I have designed industrial product with batteries and the battery was sized to give an initial operating time twice as long as the required, producing a shallow discharge and leaving margin for battery ageing. Provision were installed to cut out the battery when fully discharged.
 
Probably start a firestorm here, but I don't mean to. I must be seriously repressed because not only do I not like anything in the workshop with batteries,

Not necessarily when I was in the air force shop we had and used digital calipers probably mitutoyo. But for the mobility box we had dial calipers. the last thing you need to worry about in a remote location is a replacement battery.

There are common mistakes made with replacement batteries and import calipers. 1 do not buy alkaline cells they do not last. LR44s are useless for this application but often supplied because they are cheap. and do not buy SR44s from wally world they are expensive . buy batteries from SR44.com in bulk and freeze them.If you buy 25 it will cost you$1.36 each buy 50 and the price drops to $1.18 each and yes this includes shipping.
I have no affiliation with this site. IIRC a mom trying to take care of business and provide a quality product. these are energizer brand 357 batteries not cheap knock offs.
I do like some battery power tools but will leave that discussion for another time and thread as not to derail this one.
Tin
 
Many of the Mitu mic's still have graduations on the barrel so if the battery fails, you are not stuffed. Not sure if there are any calipers that have this.
 
The battery in my Mitutoyo digital micrometer is still going after 2 years. I reckon that's pretty reasonable. I hear some cheap Chinese measuring tools will chew through the batteries.
 
yes the cheaper ones the batteries do not last as long I have several digital calipers in my shop and a couple digital indicators, and a digital mic. so I buy batteries in bulk. I buy batteries less than once a year.

Many of the Mitu mic's still have graduations on the barrel so if the battery fails, you are not stuffed. Not sure if there are any calipers that have this.
My Hf mic has this feature as well .
My grizzly import caliper has 1mm and 1/10 in graduations so you can estimate with out a battery.
Tin
 
Not sure what Mitutoyo does with the design of their battery measuring instruments, but I agree with Jack. Both my Mit 6" caliper and quill caliper on the mill are 2 years+ on the original batteries. Same with the Starrett 0-1" micrometer.
 
Lets try this one more time and maybe it won't get lost again.

I've got to say I agree 100% with Tin's and others points. I have at least 8-9 pieces of Mitutoyo digital equipment and there's no doubt there's huge differences between it and the cheaper offshore equipment. With fresh SR-44's I usually get 3 + years, and over 5 years in one instance. Mitutoyo use there own design internal electrical circuit that does from what I've read totally shut the equipment off when it's not in use. With the cheaper equipment, only the display shuts off and the rest is still powered up. Those LR battery's are just good enough to keep you going till you find some SR's. I also have a not too bad offshore digital caliper I paid about $45.00 for. I usually get 6-8 months with a brand new SR-44 battery in that one. To state the obvious, all of this equipment isn't created equal.

My information may not be totally up to date, but the Long Island Dial Indicator Repair website had some information not too long ago about there thoughts and findings with todays avalible digital equipment. At my last reading of it Mitutoyo was rated as the best, and even Starrett digital equipment was rated as much poorer. Starrett may or may not have changed there equipment design since I've been on the website.

And it is digital, but I've got a set of Mitutoyo solar powered calipers. No battery changes at all for at least many, many years before you'd need to change out the built in internal battery on those. With at least Mitutoyo equipment, the multiple years between battery changes don't have any issues for me. And if your using a good DRO in your shop? You do have something with an internal battery back up so it can maintain it's memory. It's almost impossible today to go through life and not have at least something with a battery in it. If your reading this, your computer has one.

Pete
 
24 hour Batteries also have energizer 357s at a better price .Less than $ 1.00 each but do not know shipping costs.

Tin
 
the trick to extending the battery life on the Mit micrometer and some other digital's is to set the spindle lock often just the vibration on a tool box or work bench will keep turning it on
 

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