[EE]:: How does an electronic "Vernier Caliper" work?

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[EE]:: How does an electronic "Vernier Caliper" work?

RussellMc
EE as it's electronic-mechanical and you could build one at home.

The method of operation of ye olde mechanical vernier calipers is well
enough known to anyone who uses them, as at least knowing (if perhaps not
quite understanding) is an integral part of using them.

But, how do the electronic versions work their magic?
Much the same, as it happens.

Mitutoyo filed a "digital vernier caliper" patent in 1986.
Far later than I'd have expected.
Useful but somewhat 'dense'.

               https://patents.google.com/patent/US4878013A/en

              PDF:
https://patentimages.storage.googleapis.com/ce/85/37/e28e661f192e35/US4878013.pdf

A 23 minute tear-down and ponder of a cheap ebay caliper.
I've only skimmed it. He seems to be rather 'feeling his way' but provides
a good look at the mechanics of how it works. Mechanically they are
amazingly simple for what they achieve.

                  https://www.youtube.com/watch?v=fKSSY1gzCEs

Digit-Cal appears to be most commonly associated with Browne & Sharpe. TESA
may be badge engineering?

TESA 1977 Digit-Cal
1977 - DIGIT-CAL

The year of the worldwide launch of TESA DIGIT-CAL® with numerical display.
This new electronic calliper was to disrupt the working habits while
leaving TESA’s competitors far behind.

1970 B&S
https://www.practicalmachinist.com/vb/attachments/f19/29665d1293739201-antique-electronics-b-s-digit-cal-caliper-img_0815b.jpg

*Black hole:  *
Surprisingly fascinating Mitutoyo "History of vernier calipers".
E12029 The origin and evolution of calipers. 60 pages.

        https://www.mitutoyo.co.jp/eng/support/service/catalog/08/E12029.pdf

Digital Calipers - page 49 - section 14.

Capacitive sensor invented in 1972 in Switzerland.

__________________________

*Mitutoyo absolute caliper, 0.01 mm resolution, 1993*
Uses coarse/medium/fine capacitive tracks plus optical on fine track.

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Re: [EE]:: How does an electronic "Vernier Caliper" work?

Mike snyder-2
I have always had a back burner project to try and make a diy electronic
caliper. Obviously I am not the only one... Others have hinted at the
utility of a cheap long linear encoder

https://electronics.stackexchange.com/questions/6713/how-does-an-electronic-caliper-work

but have never really made any progress towards building one - maybe
someday :-(



On Fri, Feb 19, 2021 at 6:37 AM RussellMc <[hidden email]> wrote:

> EE as it's electronic-mechanical and you could build one at home.
>
> The method of operation of ye olde mechanical vernier calipers is well
> enough known to anyone who uses them, as at least knowing (if perhaps not
> quite understanding) is an integral part of using them.
>
> But, how do the electronic versions work their magic?
> Much the same, as it happens.
>
> Mitutoyo filed a "digital vernier caliper" patent in 1986.
> Far later than I'd have expected.
> Useful but somewhat 'dense'.
>
>                https://patents.google.com/patent/US4878013A/en
>
>               PDF:
>
> https://patentimages.storage.googleapis.com/ce/85/37/e28e661f192e35/US4878013.pdf
>
> A 23 minute tear-down and ponder of a cheap ebay caliper.
> I've only skimmed it. He seems to be rather 'feeling his way' but provides
> a good look at the mechanics of how it works. Mechanically they are
> amazingly simple for what they achieve.
>
>                   https://www.youtube.com/watch?v=fKSSY1gzCEs
>
> Digit-Cal appears to be most commonly associated with Browne & Sharpe. TESA
> may be badge engineering?
>
> TESA 1977 Digit-Cal
> 1977 - DIGIT-CAL
>
> The year of the worldwide launch of TESA DIGIT-CAL® with numerical display.
> This new electronic calliper was to disrupt the working habits while
> leaving TESA’s competitors far behind.
>
> 1970 B&S
>
> https://www.practicalmachinist.com/vb/attachments/f19/29665d1293739201-antique-electronics-b-s-digit-cal-caliper-img_0815b.jpg
>
> *Black hole:  *
> Surprisingly fascinating Mitutoyo "History of vernier calipers".
> E12029 The origin and evolution of calipers. 60 pages.
>
>
> https://www.mitutoyo.co.jp/eng/support/service/catalog/08/E12029.pdf
>
> Digital Calipers - page 49 - section 14.
>
> Capacitive sensor invented in 1972 in Switzerland.
>
> __________________________
>
> *Mitutoyo absolute caliper, 0.01 mm resolution, 1993*
> Uses coarse/medium/fine capacitive tracks plus optical on fine track.
>
> ....
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
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Re: [EE]:: How does an electronic "Vernier Caliper" work?

Sean Breheny
While Russell is dead-on about how electronic calipers work, I've also seen
digital micrometers (generally about 10x more precise) which use simply a
well-designed gear reduction followed by an optical encoder. That might be
a simpler way to go for a DIY project.

On Fri, Feb 19, 2021 at 1:08 PM Mike Snyder <[hidden email]> wrote:

> I have always had a back burner project to try and make a diy electronic
> caliper. Obviously I am not the only one... Others have hinted at the
> utility of a cheap long linear encoder
>
>
> https://electronics.stackexchange.com/questions/6713/how-does-an-electronic-caliper-work
>
> but have never really made any progress towards building one - maybe
> someday :-(
>
>
>
> On Fri, Feb 19, 2021 at 6:37 AM RussellMc <[hidden email]> wrote:
>
> > EE as it's electronic-mechanical and you could build one at home.
> >
> > The method of operation of ye olde mechanical vernier calipers is well
> > enough known to anyone who uses them, as at least knowing (if perhaps not
> > quite understanding) is an integral part of using them.
> >
> > But, how do the electronic versions work their magic?
> > Much the same, as it happens.
> >
> > Mitutoyo filed a "digital vernier caliper" patent in 1986.
> > Far later than I'd have expected.
> > Useful but somewhat 'dense'.
> >
> >                https://patents.google.com/patent/US4878013A/en
> >
> >               PDF:
> >
> >
> https://patentimages.storage.googleapis.com/ce/85/37/e28e661f192e35/US4878013.pdf
> >
> > A 23 minute tear-down and ponder of a cheap ebay caliper.
> > I've only skimmed it. He seems to be rather 'feeling his way' but
> provides
> > a good look at the mechanics of how it works. Mechanically they are
> > amazingly simple for what they achieve.
> >
> >                   https://www.youtube.com/watch?v=fKSSY1gzCEs
> >
> > Digit-Cal appears to be most commonly associated with Browne & Sharpe.
> TESA
> > may be badge engineering?
> >
> > TESA 1977 Digit-Cal
> > 1977 - DIGIT-CAL
> >
> > The year of the worldwide launch of TESA DIGIT-CAL® with numerical
> display.
> > This new electronic calliper was to disrupt the working habits while
> > leaving TESA’s competitors far behind.
> >
> > 1970 B&S
> >
> >
> https://www.practicalmachinist.com/vb/attachments/f19/29665d1293739201-antique-electronics-b-s-digit-cal-caliper-img_0815b.jpg
> >
> > *Black hole:  *
> > Surprisingly fascinating Mitutoyo "History of vernier calipers".
> > E12029 The origin and evolution of calipers. 60 pages.
> >
> >
> > https://www.mitutoyo.co.jp/eng/support/service/catalog/08/E12029.pdf
> >
> > Digital Calipers - page 49 - section 14.
> >
> > Capacitive sensor invented in 1972 in Switzerland.
> >
> > __________________________
> >
> > *Mitutoyo absolute caliper, 0.01 mm resolution, 1993*
> > Uses coarse/medium/fine capacitive tracks plus optical on fine track.
> >
> > ....
> > --
> > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
--
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Re: [EE]:: How does an electronic "Vernier Caliper" work?

Spehro Pefhany
At 01:25 PM 2/19/2021, you wrote:

>While Russell is dead-on about how electronic
>calipers work, I've also seen digital
>micrometers (generally about 10x more precise)
>which use simply a well-designed gear reduction
>followed by an optical encoder. That might be a
>simpler way to go for a DIY project. On Fri, Feb
>19, 2021 at 1:08 PM Mike Snyder
><[hidden email]> wrote: > I have always had
>a back burner project to try and make a diy
>electronic > caliper. Obviously I am not the
>only one... Others have hinted at the > utility
>of a cheap long linear encoder > > >
>https://electronics.stackexchange.com/questions/6713/how-does-an-electronic-caliper-work 
> > > but have never really made any progress
>towards building one - maybe > someday :


600 pulse encoders with nice mechanical
characteristics are not expensive. I got one from
China for $20 CAD delivered (6mm shaft and no
discernable play in the bearings).

Another approach is to use the vernier principle
by overlapping two fine patterns so that a
shifting moiré pattern forms and detect that optically.


Best regards,
Spehro Pefhany


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