Digital verniers

127/128"

Yes I've got one of those

Neil

@Michael Gilligan could tell you and might even make an offer for it.

It's a micro-adjuster for microscope slides, fits on the stage of the scope, the curved arm at the top holds the slide secure in the corner. You can move the slide very accurately to take exact measurements.

Neil

I suspect optical distortion - the exterior jaws of the caliper measure about 30 1/2 mm on my screen, whilst the inside nibs appear under 28, yet if the scales in inches the reading is undoubtedly in 128ths as there are 8 of these in a 16th, and there are 16 divisions between the 1 and the 2.

I've seen 128th Verniers often at junk tool stalls on flea markets etc., which IMO is the best place for 'em. I certainly can't imagine anyone ever actually using one, except maybe to mark up carpentry timber in whole inches or major fractions.

Oh, and setting conundrums to see if folk actually understand how to read such a scale.

.

No need for my input, Neil ... Your description is adequate.

This type is usually known as an “attachable mechanical stage” ... because it’s ‘bolt on goody’ to upgrade a plain stage. There’s a lot of good engineering there for £3.

[Stevie] If the action is stiff; thin the solidified grease down a little with ‘PlusGas formula A’ or similar ... to save damaging the mechanism.

MichaelG.

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Edit: You will note, of course, that there are Vernier scales on both axes.

Edited By Michael Gilligan on 25/01/2020 14:57:55

Correct as it does say Vickers instruments on a plate. The guy did say something about a Microscope.

deleted

Edited By Sam Longley 1 on 25/01/2020 17:30:45

Michael. The action is super smooth. I walked past it several times & kept going back for another look. My brain was going 10 to the dozen thinking what could i do with that. It was so well engineered it had to come home with me anyway. I am going to make some Mandrels to hold rings in the lathe. I thought of making up some way of mounting it to the cross or top slide, so I could hold small tools very accurately.

Steve.

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That’s a great buy then, Steve

But, unless you are doing very light work, I would advise against holding lathe tools on it.

There is no locking on the slides, and the gearing is light duty

... remember, this is designed for accurately moving a little 3” x 1” sheet of glass.

Sorry, I haven’t yet identified the manufacturer ... but if you could provide a few more photos, I might.

MichaelG.

Just read back, and found mention of Vickers Instruments

Sorry ... I responded to Neil’s post rather than Steve’s

Vickers absorbed both ‘Baker’ and ‘Cooke Troughton & Simms’ ... so there is still a bit of detective work required.

MichaelG.

Sorry guys I forgot to post the other pic of it. been flat out all night on the lathe. Here you go. Also the job I was intending to do with it was very fine polishing work. I love detail & most of the coin rings being made on the youtube, mainly in the states involves copious amounts of sandpaper. Basically wrecking the fine detail that could be.

Ditty. My neighbour gave me a full bottle 13kg of butane for my garage heater & a regulator. I said how much do I owe you. Is answer was make me one of those rings. I just need to find out when he was born so I can select the right year coin. Sorry digressed again.

Steve.

Whats a battery?

A measuring instrument with a battery?

Where have i been these last decades?

For easy peasy quick 'n cheeful i use dial calipers.

For precision, the vernier calipers

for proper precision, the mics.

No batteries were harmed in this post.

A couple of points;

First paragraph - other way round, Established Western brands inc Starrett have a cheaper line where stuff is made in the "Far East". They are the ones gladly outsourcing to Chinese factories.

Shareholders love it, the end user not so much.

You can buy a Starrett dial caliper for $40 or $300, the choice is yours.

Re, Mitutoyo made in Brazil. A Mit factory making the same Mit item with THE SAME PART NO. for worldwide sale should have the same quality. There is no such thing as "semi skilled staff not following normal Mit high stds". It does'nt happen, and Mitutoyo would not let it happen.

You either got a dud (rare) or a fake (common).

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Go for it, Steve

It looks very much like the attachable stage for the M15 ...

**LINK**

https://dlib.york.ac.uk/yodl/app/home/search?query=m15&pageSize=96

... or maybe the M14/2

MichaelG.

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Edit: Drifting even further from the ‘digital’ aspect of this thread: You may be interested to see the focus mechanism that was used on that series of stands

https://worldwide.espacenet.com/patent/search?q=pn%3DGB877813A

Edited By Michael Gilligan on 26/01/2020 05:19:41

Well spotted, the tape measure is in Chinese Inches, of which there are 30 to the metre.

I bought the Vernier thinking no batteries and reasonable accuracy would be useful for quick checking, like telling the difference between ⅛" and 3mm brass rod, and confirming twist drill sizes. In practice, my vernier is rarely used because it's so much faster and safer to read a digital display. Even cheapo digital calipers are more reliable.

The inch scale is graduated in 1/128"s . I find it difficult to decode, and once done 1/128th of an inch seems particularly useless! For woodwork, imperial sizes down to 1/16" are jolly useful. For rough hand metalwork 1/64" works most of the time. For precision work my lathe and mill both do better than 1/128", getting to about a thou without much bother. As a metric worker, measuring to 1/128" doesn't do much for me, and I suspect most imperial workshops are unfamiliar with it too. In metric mode, the caliper reads to 0.05mm, also not particularly useful.

The metric vernier on the same instrument is both harder and easier! On the up side, everything being in tenths requires fewer mental gymnastics. On the downside, while the imperial vernier scale has only 8 graduations to eyeball, the metric scale has 20! I squint at it!

After mastering the usual feel needed to get repeatable measurements from any caliper, vernier caliper disadvantages include:

1. Answers may be in an inconvenient fractional form, or the scale being tricky to read.
2. Though it's spot on, mine cant be re-zeroed.
3. Accuracy depends on two physical scales being applied correctly to the instrument, with lines spaced accurately and bold enough to read without being thick enough to be ambiguous.
4. Results depend on the users eyesight and him avoiding parallax errors carefully.
5. Decoding a vernier takes ages and is error prone. The scales have to be scanned for the nearest match and then interpreted correctly. I suppose people get better with practice but I make lots of mistakes.

Early theodolites relied on beautifully made vernier scales viewed through a small microscope. As errors were likely and most surveys took at least several hundred readings, the amount of record keeping and error checking done was extraordinary, both in the field and back in the office. A 3 or 4 man job. Two to carry the equipment and set up poles & chains etc, the surveyor, and an assistant taking notes and protecting the theodolite from rain, snow and wind. Amazing what chaps achieved in the past with simple tools and extreme patience.

Dave

Early theodolites relied on beautifully made vernier scales viewed through a small microscope.

Accuracy was/could be incredible. There is a story of a project to map something in India (I think). They travelled around 1500 miles in a loop and were amazed/disgruntled/perplexed as to why they were about 150 yards (it may even have been only 15 yards!) out when they arrived back at their departure point.

It transpired that they had been ‘fooled’ by a large mountain, some way distant from them part round the trek, which had altered the Earth’s local gravitational pull on the theodolite - leading to not setting up the theodolite exactly vertical with the centre line of the planet - and that neatly accounted for the ‘error’ found.

Edited By not done it yet on 26/01/2020 12:55:53

1. The only Verniers I've ever bought or considered buying are those where both the fixed and moving scales are flat and level together. The Mitutoyo I still have is like that. Anything else introduces parallax risks, and there's really no excuse for designing a Vernier that carries those. Of course, a lot of the 128th Verniers are not only bevelled and/or stepped, but also stamped out using 1950s can-opener technology. I think they belong in the "Nothing Works And Nobody Cares" bucket.

2. I don't *think* I've ever made a serious error misreading a Vernier. I've made far more misreading drawings, especially the datum position.

You had really good buys Steve. well done

I still have two pairs of Mitutoyo Vernier calipers, they don't seem to make them any more. See if you can identify the improvement over the ordinary type.

I've told you once!

Mine looks the same, but a bit more worn. The flat and level fixed and sliding scales prevent parallax errors better than others I've seen.

My Mitutoyo Vernier Height Gauge has a bevelled sliding scale, but at least it mates very well as it meets the fixed one. There's also a mounted magnifier the reduces risk of reading error.

Edited By Mick B1 on 27/01/2020 20:07:42