REview - SHAHE Digital calipers

Internal measurement …

yes , tricky bit of business that …

I don’t have anything of a known dimension …
The only things I have are piston cylinder assemblies ( model airplane )
And the tolerances are very tight ( Microns ) …
But the issue would be the flat blade that introduces a variable …
I can measure a piston , and then the cyl it goes into , but the variable would be the flat of the blade ( int measurement )
I would require something square , with a object that is a firm fit inside … but even then ? there are variables …
I will pull out a piston cyl assembly and see what it returns …

Ok measured a piston cyl assembly

Piston Measured 0.591 inch ( external )
Cylinder Measured 0.5905 inch ( internal )
Half a thou smaller measured , this would be due to the flats on the blade inducing an error on a cylindrical object .
( 2.5cc Piston Cyl assembly from a K&B Conquest )

Seriously , that’s good … ( Measurement was expected )
that 0.0005 accuracy is sweet …

Thanks. :+1:

No problem …

Love good tools …

Very nice unit, thanks for the review. Do you think that this unit will hold its measuring precision over time? I’ve found that all my digital calipers (cheaper ones) all work good at the beginning. Then they start to act “funny” and I lose confidence in them.

I find no reason to think these will go bad !
I own quite a few calipers and none have gone bad , I have one that was bad from day one …
I was planning on a Caliper Article …
The good the bad and the ugly so to speak …
I have a set of digital calipers that I have had for years , dont ask me how many years and they have worked extremely well … ( Not expensive ) .
So if you purchased a pair that is NQR , well stuff happen …

So far I have seen nothing that might lead me to believe these wont be good …
But like I mentioned , I am planning on doing a article (?) on calipers in general talking about some of the ones I own .

A firberglass vernier is handy to have for messuring cells as an steel vernier will short them out and we all know what happens then, they are quite cheap £5-10 on eBay.

I have a Mitutoyo digital vernier i bought 20 years ago for £80 and it`s great when accuracy is required.

John.

Yeah , I have the fiber vernier’s ( plastic ) …
I have dial and digital …

My Mitutoyo Calipers are Dial and around 30 years old …
I also have a digital Mitutoyo Micrometer that measures microns , for some serious accuracy …

My calipers …

Hi, first of all, thank you for taking the time and writing a review on this caliper. However, unfortunately there is hardly any technical value in your tests and it rather reads like an advertisement for the caliper rather than a thorough testing, since you could come to the same conclusions with a 10$ caliper. I know it is never easy to test measuring tools, but here a few tips:

  • Usually you use precise objects to judge the precision of a measuring tool. That could be a setting ring for inner measurements and a gauge block for outer measurements.
  • If you don’t have any of the above things, you should have something that is more precise. For example a micrometer as well as a precisely ground steel rod, since judging the precision with other measuring-tools which are equally precise does not work.
  • Perform measurements with objects at different places in the chucks. For example measure something right at the tip of the chucks and the same thing completely inside the chucks. (Like the guy here does for example)

Further it would be interesting whether or not the caliper came with a specification sheet and more importantly an actual calibration/ testing sheet.

The steel rod mentioned was measured by all my calipers …
So that’s the tested caliper + 8 other calipers …

Technical value ? / How so …

Even high priced Mitutoyo has variance from one caliper to another to some degree … ( I have worked in several engineering environments over the last 3 decades )
It does not matter if there is variance as long as you work with the same calipers and the calipers are reliable ( offer repeatable measurement )

Ok I did not elaborate on how I tested the calipers , so what ?
I tested a steel rod for OD and LENGTH , this gives two vastly different readings …
And the steel rod was measured with all my calipers … ( See picture )
And yes , I did measure at different points ( jaws ) to see if there was variance …
These days I cant be bothered talking about stuff that does not need talking about …
If its good , its good . Why go on about it ?
If something is NQR , yes talk about it , even offer a solution if there is one .

As for my Micrometer , it is limited to 25mm and is accurate to microns … But it is hardly relevant as it offers a much more precise result .
So I compared a Vernier Caliper with my other Vernier Calipers …
And since they all gave pretty much the same result ( depending on capable accuracy scale )
All the calipers pictured are good and accurate within their capability ( accuracy scale )
The only calipers I would and could not recommend are No4 …. These were bad from day one …
I only kept them around for this picture and for when I do a caliper write up …

And then I will do a more detailed description on all the calipers I own … + Known issues that may plague a caliper …

But thank you for taking the time to share your expertise …

since judging the precision with other measuring-tools which are equally precise does not work. = Gee , Im glad I am not an expert !
( Imagine owning several vernier calipers that all give the same measurement - on any given object ) = That does not confirm anything now does it … ( ? )

And how can a tool that measures 0.1mm compare with say a tool that measures 0.02mm or with a tool that measures 0.001mm … or to a tool that measures 0.0001mm and so forth …
I think a little common sense needs to be applied …

You have tools for measuring ball park ( near enough is good enough ) like 18650 batteries ( do you need more than 0.1mm ? )
Plastic calipers are great for this …

And then when you need a more precise measurement , one thou usually does the trick …
When working with model airplane parts ( Making pistons , crank shafts ) then a more precise measurement might be needed ( usually work in Microns here )
Working in engineering shops , I never encountered a need for more accuracy then + - 5 thou … So if you have calipers that can measure to half a thou ?

Anyhow , these days I measure screws , batteries , and other nick nacks and 1 thou is serious overkill …
Anyhow , vernier calipers in engineering environments are usually used to get you within a certain tolerance range ( that you are machining too ) and if it has to be + or - 1 thou , then you usually switch to the micrometer before reaching critical dimensions …

Oh !!!
And lets not forget , the more accurate the measuring tool , then the more sensitive it is to variables like temperature …
When you have a tool that can measure say a micron , then the temperature of the tool becomes critical …
I fondly remember having to constantly re zero because of temperature induced variance …
And the same goes for what you are machining …

Been there done that …

Because you could have come to the same conclusion with a cheap 10$ caliper since we don’t know what kind of testing you did. This caliper is around 35$, that means it’s overkill for anyone who wants to measure cell length and “normal” every-day things and consequently its is expected that the caliper plays in the same league as some good 50$ - 150$ calipers, otherwise there’s no point in ordering it from china and sacrificing warranty and local customer service. And for this price range it would be good to have some hard facts.

Yes, but Mitutoyo calipers have a way smaller variance than a 10$ caliper. And it would be interesting to know how much off to the true measurement the SHAHE one is. Of course it’s only one model and doesn’t tell us very much, but it’s a start.

Why elaborate about how you came to the conclusion? Well that’s the most important part and a crucial part about a good review. Otherwise we’d have light reviews saying “I recommend this light” and nothing more. But that’s not the case, because it is important for the reader to comprehend what led the review-writer to the decision that it’s a good light and tells the reader what kind of standards the reviewer has. This includes measurements, thoughts, and so on. Ideally I can come to my own conclusion based on the review, if I think the light/ caliper/ … is good for me or not. For example for me this caliper is of interest because it would be nice not having to use my expensive one when there’s a lot of oil and dirt around, but I would like to know how it compares to the caliper I use.

Why go on about it? Because someone who wants to find their way around the house and isn’t into flashlights will rate a 5x5mm led light as good. Someone who is searching for a professional search- and rescue-light might give a TN42 an acceptable rating and decides to go with a Polarion. So you can’t say uniformly that a product is good for everyone, again that’s why it’s important that the readers are able to comprehend why you think it’s good.

You don’t seem to appreciate it… I did not mean to discredit your knowledge on measuring tools, I am sorry that I came off as rude.

If they all give the same reading then it good, then we know that they are all equally much off and it requires either a referenced thing or something that measures in a more precise range in order to tell how much these are off.

My boss as well as my dad (use to) have Mitutoyo calipers, my boss has a few of them. One is about as long as my arm, now you know that cost him.

I have 3, 1 major hunk of junk no possible way to be accurate. Both the other are digital and of decent brand but still affordable. I learned something one day. Now trust me I am NO expert on this subject but here is what happened.

Our resident know it all (honestly he is pretty intelligent and can do his job well) but the one thing he can't do we learned about a year ago.

He was measuring some carriage bolts that had gotten mixed up and he was using the bosses Mitutoyo. I had just bought the newest caliper I have and had just started getting use to it. So I started helping him.

Long story short we started getting different readings on the same bolts. Well he yelled and cut up like usual until the boss came out to see what was going on.

We explained it to him and Russel (the know it all) insisted I had to be wrong because he was using a far better caliper than I was.

Well the boss being the boss took both calipers and measure himself, both were dead on. Turns out I happen to be right that day. Russel was way too heavy handed.

I think going digital changed all of it but there are still plenty out there that are just not constructed well enough to compete with the accuracy of a very high end set, and then the human factor comes in as well.

Before I forget if ever decide to sell those analog Mitutoyo's please let me know. I collect all kinds of old mechanical things. Watches mostly, but I would love to add that to my collection.

I'm curious..... What would be the chances that each of us would happen to have an item that should measure out to close to the same, /if we could think of such an item we could each measure and see how far apart we are...

Either way I know one thing for sure, if I try to hurry and am not paying attention my numbers come up way off.

Always got the human factor... IMHO.

I emailed Mitutoyo in Japan years ago about finding an resell in the UK, I was told they are sold under the Kennedy brand and mine has their name on it, not Mitutoyo, I bought mine from Cromwell UK

John.

Oh dear ! …

There are international measuring standards …
Depending on the industry , measuring tools may or may not need to meet certain standards …
Same goes with certification …

To what level of accuracy ?

To correctly certify measuring tools …

Certification / verification may need to be done under laboratory conditions … Temperature controlled clean room …
Even the items measured may need to be at a certain temperature range …
Same with the tools being verified .
The more accurate the measuring tool , the more critical the temperature range it is verified under …

Again , a $35 caliper is most likely not going to be used in a environment that requires certified tools …
And if you say one caliper can’t be used to verify another ?
Then you may need to double check the standards used to check / verify measuring tools … ( Industry Standards )

Oh !
Lets not forget whats important about calipers = Repeat-ability / consistent repeat-ability …
It does not matter if they are a thou or two this way or that way …
Because :

If I measure a part , then manufacture a matching part using the same calipers …
Guess What ! There going to be the same ( depending on your machining skills )

The only time TRUE accuracy ( True reading ) is important is if you make stuff for others from blue prints and the item requires seriously tight tolerances …

  • or - 1 thou or half a thou would already be most likely beyond calipers …
    Nobody uses calipers for such tight tolerances …

Obviously this review has gotten under your skin …

And I dont have a temperature controlled clean room , so ?
I certainly cant verify anything to the standard you would like …

Hm, I guess I expressed myself in a bad way, sorry. English isn’t my first language. OK, so what I meant is a spec sheet which gives the specs for all the calipers of this type. I don’t think it’s to much to ask for something like that to be within the package. Additionally it would be nice to have an individual spec sheet, like Mitutoyo calipers have. Also shouldn’t be such a big problem, considering how cheap the wages are in china. For example I got a Granite plate for around 80$ which came with an individual spec sheet.

You are right, but it’s not that strict with calipers. For calipers it’s enough for the temperature to be somewhat around 20° Celcius.

No, but it still would be nice to know how good it is.
I actually checked, here is one pdf for example. You need a granite plate, a micrometer and a master gauge block set. Another way is to use a set like this one (sorry for the links to a German shop). If you use one caliper which let’s say has an accuracy of 0.025mm to verify another one which also has 0.025mm accuracy you suddenly have only an accuracy of 0.05mm to the true value since the errors can add up. That’s why usually more precise tools are used to verify/ check/ calibrate less precise measuring tools.

True, but if you have the chance to measure how much this way or that way is, why not do it then?

You don’t need a clean room to measure how much off the caliper is. Nor do you need a clean room to measure how the measurement changes when you move an object within the chucks. Both of those things are quite handy to know and do not require a clean room or something like that and unless you live in Alaska or Australia your rooms should be around 20°C which is also perfectly fine. Maybe I will just order it and test it out myself then :slight_smile:

Actually !
I have worked in several industries / factories / work places where temperature controlled clean rooms were mandatory …

I worked at ControlData ( an American company ) that made computer disks here in Moorabbin ( Melbourne Australia )
Must have been like 1981 to 83 or something …
And they had a temperature controlled clean room for making Disk drives ( The large disks ) for the mainframe computers …
Some time in the 90’s I worked for a company that made parts for 747’s …
The factory had to be maintained within a certain temperature range …
Some critical components had to be checked in a temperature controlled clean room within a specified temperature range ( I cant remember what it was )
And the same with the measuring tools …
They needed to be checked within a certain time frame ( certified accurate ) in that same room …
There literally was no room for dodgy measuring equipment .

I had never seen so many calipers and micrometers in any workplace before … And the best assortment / size I have ever seen …
Also one of the first places I ever saw laser measuring tools . ( Actually the only place )

Again it just depends on what standard you are working too ( Measuring too )
I don’t own anything that could be used to certify a measuring tool … ( And there fore I would not even attempt such )
Either do it properly , or not at all .

General caliper chit chat posted !

Ok … here is a vid comparing Mitutoyo Micrometer with my calipers …

Just a comparison / verification …

I had trouble finding something round enough to give a consistent measurement …
Ended up with this Alen driver … Gave a consistent 12.480mm
Room temp was 20.2 Deg C ( If you trust a Chinese thermometer )