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Bad vernier calipers?
Slimy38 - 17/4/18 at 08:54 PM

I bought a set of vernier calipers from Ebay, I thought I'd gone for cheap but serviceable. It doesn't seem like that though;



Unless I've misunderstood how these work, when they're closed the two zero's should line up.

First off, is that expected? If so, is there a way I can manually calibrate them? I'm thinking some light application of a file perhaps? Or am I asking for trouble?

I could just return them, but I do wonder whether I'm asking a bit much for a silverline tool?

02GF74 - 17/4/18 at 09:07 PM

Yeah, that's bad.

I'm wondering if the 3 crosshead screws hold the scales in position so adjustment is possible?

Slimy38 - 17/4/18 at 09:13 PM

quote:
Originally posted by 02GF74
Yeah, that's bad.

I'm wondering if the 3 crosshead screws hold the scales in position so adjustment is possible?


The heads are quite tight in the holes though, there's no movement available. But I like the idea, perhaps I could elongate the holes to make them adjustable.

gremlin1234 - 17/4/18 at 09:34 PM

whilst that is on their minimum reading, the actual measuring edges do also have gaps, you can see light though the tips, and the internal measurement jaws overlap.

try measuring a known size, and see what it says.

steve m - 17/4/18 at 09:38 PM

I have some similar, there not perfect, but within a millimetre in calculating

Not bad for £7.50

steve

bi22le - 17/4/18 at 09:39 PM

You are fighting for a 10th of a mm on manual calipers?

If you are working to less than that ( which you would be if 0.1mm is not accurate enough) then you have the wrong tool in my eyes.

You would be better of with digital calipers or a micrometer.

I would just leave it, and if you are working that small consider it in the measurements you make.

perksy - 17/4/18 at 09:41 PM

To be fair it might be better to buy a good secondhand pair made by Moore and Wright or Mitutoyo if you want to do some accurate measuring?

Just depends on what your using them for and how accurate you want them to be

Andy B - 17/4/18 at 10:17 PM

It’s not a mechanical fault, it’s a difference in the two printed scales
It’s out at 0 but catches up by 2 and then runs out the other way
Bearing in mind it’s supposed to be a precision tool imho it’s not fit for purpose

ReMan - 17/4/18 at 10:18 PM

im on my 3rd pair of digital verniers, £10-20 and they been great, only failed due to my hamfistery

gremlin1234 - 17/4/18 at 11:47 PM

quote:
Originally posted by Andy B
It’s not a mechanical fault, it’s a difference in the two printed scales
It’s out at 0 but catches up by 2 and then runs out the other way
Bearing in mind it’s supposed to be a precision tool imho it’s not fit for purpose

its a vernier scale, the offset gives more than 10 times the precision, when you know how to read it.

Andy B - 18/4/18 at 03:28 AM

Well you learn something every day - always used digital

nick205 - 18/4/18 at 08:03 AM

Doesn't look great to me.

I've had various Silverline tools through the years. Whilst they're at the budget end of price they're not usually the best of quality.

http://www.halfords.com/workshop-tools/tools/hand-too ls/laser-digital-vernier-caliper-150mm

I've got a £20 digital vernier calipers from Halfords. Cheap enough and they're bang on accurate when checked with more expensive and calibrated Mitutoyo digital vernier calipers we use at work.

nick205 - 18/4/18 at 08:12 AM

quote:
Originally posted by Andy B
Well you learn something every day - always used digital



Same here at work and at home!

My 70 year old Dad talks to me about using "slide rules" back in his day - another mystery to me!

nick205 - 18/4/18 at 08:45 AM

Looking again at the photo I'd ask for a refund and send them back.

Always good to use signed for delivery when returning things so you get some evidence it's actually got there.

Bigboystoys - 18/4/18 at 11:43 AM

Can't go wrong with a set of mitutoyo buy once and they last a lifetime

907 - 18/4/18 at 11:59 AM

You get what you pay for ..........

except on eBay, where you get rejects of what you payed for.




There's remarks on some posts that Moore & Wright or Mittatoyo will last a lifetime.

My set came from a gentleman that died at the age of 84, eight years ago.
He worked for Marconi on military guidance systems.
They have thread info on the back for BSW.



Paul G

nick205 - 18/4/18 at 02:45 PM

quote:
Originally posted by 907
You get what you pay for ..........

except on eBay, where you get rejects of what you payed for.




There's remarks on some posts that Moore & Wright or Mittatoyo will last a lifetime.

My set came from a gentleman that died at the age of 84, eight years ago.
He worked for Marconi on military guidance systems.
They have thread info on the back for BSW.



Paul G



"BSW"

Not heard of that for a while!

Machine shop I worked in 20 years ago had a dusty set of BSW taps and dies.

02GF74 - 18/4/18 at 03:27 PM

quote:
Originally posted by bi22le
You are fighting for a 10th of a mm on manual calipers?

If you are working to less than that ( which you would be if 0.1mm is not accurate enough) then you have the wrong tool in my eyes


They are capable of resolving 0.02mm.
OK, so an overkill for most tasks but sometimes you need that.

Send them back and try again or different brand.

Digital vernier calliper are for those who can't use or understand vernier gauge, and are fine until the battery runs out, and trust me, unless you use them every week thus keeping on top of the battery condition, the time you come to use them, they are definitely = useless.

StrikerChris - 18/4/18 at 03:32 PM

That looks about 0.2 when it should be 0. if youve got a known say 100mm parralel or something and its still 0.2 over then atleast you can use it roughly! If the scales out tho its completely useless. I'd just buy a decent one,its something you'll use forever,and at some point you'll make a cockup because of it!

Chris

snapper - 18/4/18 at 05:15 PM

I bought a pack of 3 set squares from Lidl only to find after cutting some panels the big one was out, Doh

Slimy38 - 18/4/18 at 09:41 PM

They were bought to replace a digital set, unfortunately as mentioned by the time I came to use them the buttons had worn away and the display panel was shot. They were from Aldi, and the same price as these silverline. It almost seemed like they just weren't suitable for life in an average home garage.

I think I'll try and tweak them, I was after 0.1mm resolution so they should suffice if I can get the zero's to match. I'm not measuring engine tolerances with it, but I do want better than the 0.5mm resolution that I can get from a rule.

Thanks all for the replies.

907 - 19/4/18 at 06:58 AM

At least with non digital if they are 0.2 out they will always be 0.2 out, and you can make allowances.


I bought an Aldi set of digital for use in photographs as they show up nicely.

However, when used on the lathe if slid back and forth a few times when returned to zero they can read anything.
Then there's the times when they time out and switch off so you start all over.


I still wouldn't return them as I bought them knowing they were cheap crap, and they do what I bought them for.

I just hate digital. Must be an age thing. I dread the day when my analogue multimeter goes wrong. (30 years old now)


Paul G

owelly - 19/4/18 at 11:28 AM

Slimy, what you've bought, is a flimsy chipping-hammer. Name and shame them on Twitter to make you feel better and they may send you some equally crap free stuff....

Slimy38 - 19/4/18 at 12:00 PM

quote:
Originally posted by 907
At least with non digital if they are 0.2 out they will always be 0.2 out, and you can make allowances.


I bought an Aldi set of digital for use in photographs as they show up nicely.

However, when used on the lathe if slid back and forth a few times when returned to zero they can read anything.
Then there's the times when they time out and switch off so you start all over.


I still wouldn't return them as I bought them knowing they were cheap crap, and they do what I bought them for.

I just hate digital. Must be an age thing. I dread the day when my analogue multimeter goes wrong. (30 years old now)


Paul G


That's the same I had with my Aldi ones. I'd set it to zero then measure something, but when I set it back to zero it was usually out. And don't even get me started on that damned time out, I swear it was set to reset at exactly the wrong time.

Hence me going for something 'old fashioned', at least if it is wrong it's always wrong by the same amount.

JonBowden - 19/4/18 at 06:13 PM

for my use, I have now banned anything that says Silverline on it.
I have wasted too much time on their stuff that is not good enough to do what I need

I do sometimes buy cheap tools and sometimes they are ok, just no more Silverline

Benzine - 19/4/18 at 06:51 PM

quote:
Originally posted by JonBowden
for my use, I have now banned anything that says Silverline on it.


Likewise. Worst ratchet straps I've ever used.

mcerd1 - 19/4/18 at 07:38 PM

they really do look quite poor there is no excuse for the scales being noticeably off on any precision tool IMHO


[rant mode on] Also I've always had an issue with calling all the digital ones "digital vernier calipers" - they are just 'digital calipers'
it can only be a vernier if its got an actual vernier scale on it ! (vernier scales are on lots of things not just calipers)

also while were at it cm should be banned from all proper measuring devices, the main sale on that one should read 10, 20, 30 etc.. not 1, 2, 3....
the only acceptable metric units for any kind of engineering are nm, µm, mm, m or km !!!
(and don't get me started on deci meters and deca Newtons - French engineers seem to love them, but all they do is cause errors )
[rant over...]



Personally I've still got a dial caliper that I got for my 21st - a bit more expensive than a vernier but much faster / easier to read



lastly for those that don't know about the vernier scales:
https://en.wikipedia.org/wiki/Vernier_scale

and this ones not too bad: (most videos seem to be for the imperial versions, same idea but why make it more conffusing)
https://www.youtube.com/watch?v=vkPlzmalvN4

the only way to get good at reading them is lots of practice

[Edited on 19/4/2018 by mcerd1]

[Edited on 19/4/2018 by mcerd1]

mcerd1 - 19/4/18 at 07:49 PM

quote:
Originally posted by nick205
"BSW"

Not heard of that for a while!

Machine shop I worked in 20 years ago had a dusty set of BSW taps and dies.


We still use new BSW bolts on structures at least a few times a month....

nobody wants the hassle of remaking the whole thing when they don't have to, so repairs, upgrades and replacements on old ones are still done with imperial bolts
(and I really mean imperial, none of those american UNC bolts here thank you very much )

[Edited on 19/4/2018 by mcerd1]

907 - 19/4/18 at 08:24 PM

My lathe and my guillotine have BSW bolts.

Because of their larger head they are especially good for slotted holes.

sdh2903 - 19/4/18 at 09:44 PM

quote:

only acceptable metric units for any kind of engineering are nm, µm, mm, m or km


Try telling that to anyone in the aerospace industry.

907 - 20/4/18 at 02:30 PM

Apparently when you are little you can only see big things, hence at school they teach centimetres as the smallest measurement.


Having had this brainwashed into you for a quarter of your life its difficult to escape, which is why we as a nation can't make anything anymore.

Even the manufacturing that does exist has to be owned and run by foreigners. Sad init.


Paul G