Vernier Calipers, anyone use them?

[Refugee]

You do need to take the batteries out of Aldi/Maplin ones otherwise the battery contacts become contaminated by the battery. They don't visibly leak but do make the contacts intermittent.

[Vintage Engr]

Agree with others, a good quality one like Mitutoyo are well worth having. Used daily.

[Lloyd 1985]

I’d never used such a thing until I did an engineering course at college (in 2002!), we had proper vernier callipers and micrometers, wondered how I’d ever managed without them! A friend at college had splashed out on some nice Mitutoyo digital callipers, and they were really nice to use.

I only got my own digital callipers about 6 years ago, they were dirt cheap, £11! They work pretty well, but they eat button cells for breakfast.. I did buy some plastic ones, but they were rubbish, trying to zero them was difficult as they flexed too much.

Regards
Lloyd

[elanman99]

Originally Posted by 60 oldjohn

One time I did not own one, did not miss it, blundered my way through life without one. When I finally did buy one I wondered how I managed without it. Very rare a day goes by when I don't use one. Plastic one handy for measuring button cells. I never tried to understand how to use the old none dial display type. How do you feel about them?

To be pedantic, neither of the two calipers shown in your picture are 'vernier' calipers. One is more correctly called a 'dial' caliper and the other is a 'digital' caliper, but neither have a vernier scale.

Originally calipers used in engineering had two legs and pivoted joint, did not measure and were just used as a comparison device, at some time sliding vernier scaled instruments became known as vernier calipers. Dial calipers came before digital ones and as far as I know were never known as 'dial vernier calipers' (presumably because they had no vernier element in them). I'm curious now why the vernier bit became synonymous with digital calipers.

Anyway, digital calipers are indispensable, I have about eight different ones, mostly cheap Chinese but also a Mitutoyo and a Starrett. Virtually all of them give identical readings when I have compared them but the more expensive ones have a much better feel and are nicer to use.

Some have auto-off which can be a real pain if it does not retain the measurement reading (so its two pairs I never ever use)

Ian

[David G4EBT]

A point worth mentioning perhaps:

There was a thread some time ago, which I can’t find, about the short life of digital calliper batteries (LR44 cells) in which it was said that we can 'buy four for a pound at Poundland on an A4 sheet’. I can’t find the thread but I contributed to it stating that we can't buy batteries for a quid on an A4 sheet if we're buying the correct type of LR44 cell as per the instructions. Not all cells are created equal! That said, I guess that the callipers are so evidently simple to use that few of us bother to refer to the instructions.

I suspect that short battery life and malfunction of the 'flashing digit low battery warning' is most likely caused by using the wrong LR44 cells, either from false economy or ignorance. Namely, using 1.5V alkaline instead of 1.55 V silver oxide cells. It isn’t helped by the fact that the term LR44 generally refers to alkaline cells, whereas silver cells are generally referred to as ‘SR44' (sometimes ‘357’ and SR1154W).

It’s difficult to obtain data about most makes of cells, (no surprises there then!), and it makes no sense to - for example - compare one brand of silver oxide cell with another brand of alkaline. However, I’ve located the dasheets of Renata SR44 silver oxide and LR 44 zinc/manganese dioxide cells, which I’ve attached below to illustrate the differences. (Renata is a Swiss company, which is part of the Swatch group).

Not only is the starting voltage of a brand new alkaline cell only 5.0V, the self-discharge rate at 20C is about 10% a year, whereas a silver oxide cell, with the higher voltage of 1.55V when new, has a self-discharge rare of less than 5%. Furthermore, the discharge curve of each type of cell is quite different, and worse still, the capacity of alkaline cells is much lower than silver oxide.

I've got three digital callipers of various makes - all of them budget types. They all work fine and the readings compare very closely. The instructions state that the battery must be a 1.55V silver oxide. I've only got one set of instructions now (for a Clarke Brand/Machine Mart instrument) and here's what they state:

Quote:

8-<

Power Source: One silver oxide 1.55V LR44, capacity 180 mAh. Current <20uA

'Troubleshooting': Digits flash randomly or all five digits flash simultaneously: Battery Voltage below 1.45V.

Unquote.

8-<

A glance at the datasheet below of the Renata LR44 1.50V cell will show that its capacity is 105mAh, whereas the SR44 is 80% higher – 190mAh. Unfortunately, the discharge curves of each cell on the datasheets have a starting drain much higher that our digital callipers (if my Clarke one is typical at <20uA), but no doubt the shape of the curves with a current lower drain will show similar paters, though over a longer period of time).

The LR44 datasheet has a starting drain of 191.1uA, and the discharge curve is very telling. At that rate of discharge within less than 50 hours it’s down to 1.4V.

However, with the SR44 - with a starting drain of 272uA (50% higher than for the LR44 test) - the Voltage remains constant at 1.55V for 600 hours. (by which time – despite the much lower current drain on test, the LR44 has fallen to 1.2V). So even with a 50% higher discharge current, it takes more than 600Hrs for the silver oxide cell to fall to 5V – the starting voltage of a new SR44.

I’ve heard people say that they take their cell out of the callipers if they don’t use them often. Well even if you have a brand new LR44, it’s self-discharge at 10% a year will reduce the voltage from 1.5V to 1.35V - below the minimum Voltage at which the callipers will function (1.45V). A new SR44 silver oxide left in a drawer for a year will self-discharge 5%, so will have fallen to 1.47, so admittedly that too will be close to the 1.45V at which the callipers will stop working.

I won't quote any links, but a glance at ebay will find SR44 ('357') silver oxide cells by Renata and others (Duracell etc), if bought in fives, for little more than the cost of LR44.

So, whether you buy a sheet of LR44's from Poundland or a recognised brand of LR44, don't expect much life out of them as compared to SR44s. As good an example as any of 'we get what we pay for'. A rather long-winded way of saying 'don't use alkaline cells - use silver oxide', but hopefully, a bit more objective with underpinning evidence to support the claim.

Hope it's of interest (assuming that anyone has read down to here!).

[mark_in_manc]

Originally Posted by Station X

I'm on the point of throwing away my dividing head. It's much easier just to key the PCD, number of holes etc into the DRO and it'll give you the distance to the next hole.

(I would be interested in helping you feel better about throwing it away if it's a small one... feel free to PM me )

[MotorBikeLes]

Back in the '60s I bought a Mitutoyo imperial/metric vernier type. It cost £4:9:6d (I can still read it on the outer case) and it feels as accurate as it was when new.
About 15 years ago I bought a digital one, but it did not work at all when cold, even with the SR44 cell. Eventually it packed up altogether. Shortly after I got an imperial Mitutoyo dial type with a Myford lathe I bought. I recently bought a cheapo metric dial type, but might just have well thrown my money away. About 3 more cheapo digitals have come my way, two of which sometimes work. The batteries are only fitted before use or they flatten quickly, even though a current test shows barely a couple of microamps.
Just a few years ago I bought a dial type with black (imperial) and red (metric) pointers. Initially out of sync, but I managed after much trial and error to resync them, and it is my go-to for general measurements. I have quite a range of micrometers, including an "automatic" 0-1" or 1" to 2" Starret from early 1900. More indicator types than I can count, one on my flywheel alignment jig, another on a stand by lathe for centralising with a four jaw chuck, or that last few thou in the three jaw when critical.
When I started my first job, we used to measure batches of a dozen "briquettes", using a very old vernier with a most unusual imperial scale.
Took a while to master, but it means I can tackle just about any scale nowadays. Of course, a magnifier is often needed with verniers. The original Mitutoyo lives with the electronics, all the rest out with the 'bikes and machinery.
Les.

[wireless_john]

Yes, I use them. I have a Moore and Wright one that I use regularly!

John

[Uncle Bulgaria]

I see this thread, and happen to have my everyday vernier caliper next to the laptop! It's a 'MADE IN W. GERMANY' Draper with Imperial/Metric (1/64"/0.1mm vernier). Really handy for length comparisons (used more like a hinged caliper) as well.

For important things I have a wonderful ancient one in a velvet-lined case my brother gave me. Far more accurate, but only Imperial.

I am always in wonderment at M. Vernier.

[60 oldjohn]

Anyone reading this thread that does not possess a set? If so why not?

John.

[Station X]

Quite a lot of members I should think.

If I only repaired radios etc. I'd probably only use them for measuring control shaft diameters, wire diameters and thread diameters.

[Kentode]

I'm still using the Vernier calipers that my workmates at Ferranti, Moston bought me for my 21st birthday when I finished my apprenticeship and became a " Time-served" skilled engineer.

Within a week, I'd spun a very expensive bell-housing out of a lathe and down the shop floor. This was mounted on a small plinth and presented to me by the foreman!

[LeakyGrid]

Originally Posted by elanman99

To be pedantic, neither of the two calipers shown in your picture are 'vernier' calipers.

Not pedantic at all. If it does not possess a vernier scale, it is not a vernier caliper. The meaning of technical terms like this must be preserved, not corrupted.

Roger

[Station X]

Here's my Vernier Caliper. It was bought more than 30 years ago from Martin and Newby's hardware shop in Ipswich. In those days Ipswich had a least three proper tool shops. Nowadays I have to buy just about all the non DIY tools I need online.

This tool hasn't been used for about six years. Nowadays I use the Mitutoyo digital caliper which can be switched from imperial to metric and have its zero set at any jaw opening. This came from Farnell, so I'm pretty sure it's genuine.

[Radio Wrangler]

Vernier callipers came in different qualities. The best ones had the main and vernier scales coplanar, so they slid past edge to edge. Cheaper models had one scale offset with respect to the other, and you could get parallax error.

David

[Andrew2]

I have one which gets occasional use for measuring hole-sizes and suchlike. It's very good, but it drains the battery when switched off! I have to remove the battery before I put it away. I think it may have come from Maplin. I may treat myself to a new one for Christmas.

[Mooly]

Vernier calipers, yes I use mine quite a lot, particularly the depth gauge part. In fact I was using them only yesterday.

Lol, you would all have a fit if you saw them, they are made of nylon and were bought probably 20 to 25 years ago at the local '50p shop'.

They have proved their worth many many times. This image off the web but mine are exactly the same.

[60 oldjohn]

Originally Posted by Andrew2

I have one which gets occasional use for measuring hole-sizes and suchlike. It's very good, but it drains the battery when switched off! I have to remove the battery before I put it away. I think it may have come from Maplin. I may treat myself to a new one for Christmas.

My Maplin one was rubbish. My Tesa Swiss made calipers £5 from car boot £5. They have auto off which is a bonus, never had a problem with them. Where practical I would rather pick up the digital calipers in preference to a steel ruler. This is in a radio workshop, not an engineering setup.


John.

[Dickie]

This is my collection. Anyone else still got their plastic freebie from Anglia Components?

[Herald1360]

No, but I had several at one time. Not really any more precise than a steel ruler, but useful nonetheless.

Here's my present ones-

Little CK one does 128ths of an inch- had that since I was at school.

Draper one claims 1000ths of an inch and 20μm though a strong light and good magnifier might be needed!

The CK one isn't actually banana shaped, that's just my camera's dodgy macro capability.