Looking for 0.001″ resolution carbon fibre digital calipers

[GreensandsParticipant @greensands]

I recently searched for 0-6” carbon fibre (cheapo) digital callipers priced typically within the price range £5 to £15 but could only find, perhaps not unreasonably, units having a resolution 0.010”. Anyone know if they are available offering 0.001” resolution within a similar price bracket or is this expecting too much?

[GreensandsParticipant @greensands]

[Mick B1Participant @mickb1]

Posted by Greensands on 07/11/2022 15:30:29:

I recently searched for 0-6” carbon fibre (cheapo) digital callipers priced typically within the price range £5 to £15 but could only find, perhaps not unreasonably, units having a resolution 0.010”. Anyone know if they are available offering 0.001” resolution within a similar price bracket or is this expecting too much?

I think the bold bit's key. I don't know its modulus of elasticity or owt like that, but I wouldn't expect carbon fibre to have the rigidity to work to a thou with any reliability.

[JellyParticipant @jelly]

Carbon Fibre can be very rigid indeed, and interestingly you can control the rigidity of the part in each axis by manipulating the way it's laid up…

But I do find it extremely unlikely that carbon fibre that rigid can be manufactured for £15 profitably…

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jelly on 07/11/2022 16:41:13:

Carbon Fibre can be very rigid indeed, and interestingly you can control the rigidity of the part in each axis by manipulating the way it's laid up…

But I do find it extremely unlikely that carbon fibre that rigid can be manufactured for £15 profitably…

.

Yes … most unlikely !!

A few months back, I bought some cheap ‘carbon fibre’ tweezers

Most of then were broken when they arrived … presumably because the mailer that they were in had gone through the franking machine

Inspection showed them to be some sort of brittle plastic ‘reinforced’ with chopped-strand rovings of carbon fibre, in lengths too short to be useful.

… the complete antithesis of a fully ‘engineered’ filament-wound product.

MichaelG.

.

Edit: __ Temus fugit !! this photo is a year old :

 

Edited By Michael Gilligan on 07/11/2022 17:12:31

[GreensandsParticipant @greensands]

General thought inspired by the photo shown on Page 581 of the Model Engineer No. 4702, 21st Oct – 3rd Nov 2022 where the author refers to the use of an inexpensive digital caliper for use in a DRO lathe application.

[Brian GParticipant @briang]

Zoro offer a "Senator Polycal Digital Caliper" at £15.99 inc. VAT with a resolution of 0.01mm / 0.005" but this appears to be polycarbonate like the similar (identical?) M&W one. I wasn't impressed by the claimed accuracy of +/-0.02mm / 0.008", but even a Mitutoyo caliper costing 10 times the price doesn't claim to be more accurate, so I guess it is in the nature of calipers.

Brian G

[old martParticipant @oldmart]

I wonder how resistant to abrasion the jaws are? I wouldn't like to use them on anything harder than wood.

[GreensandsParticipant @greensands]

For the application in mind i.e. a lathe DRO (See ME 4702), the jaw hardness is irrelevant and can in fact be sawn/ground off as they would simply get in the way.

[DiogenesIIParticipant @diogenesii]

Chronos do a steel one but you'd have to shell out a whole £22..

Chronos Electronic Digital Caliper 6" / 150mm

..they claim 0.01mm /5 tenths resolution, 0.03mm / one thou accuracy..

[Peter Cook 6Participant @petercook6]

You only need the slider and the electronics. I used the bits from a set that the plastic case had broken, and 3D printed a replacement housing.

Works well as a cross-slide DRO.

PS Get a set that retain the zero when they switch off. The ones that reset to zero when you switch them back on are a pain as a DRO.

Edited By Peter Cook 6 on 07/11/2022 23:04:34

[DiogenesIIParticipant @diogenesii]

Just found these at RDG;

Dasqua Plastic 150mm caliper claims 1/2 a thou.

[Mick B1Participant @mickb1]

Posted by DiogenesII on 07/12/2022 17:26:15:

Just found these at RDG;

Dasqua Plastic 150mm caliper claims 1/2 a thou.

Amazing! Well done – I'm seriously tempted, just to play with it and see if it's really any good.

Just gotta get the Expenditure Appropriation through now…

[Tony Pratt 1Participant @tonypratt1]

All I can say is why, why, why?

Tony

[Robert Atkinson 2Participant @robertatkinson2]

Posted by DiogenesII on 07/12/2022 17:26:15:

Just found these at RDG;

Dasqua Plastic 150mm caliper claims 1/2 a thou.

Hmm, I don't see any accuracy claim, just a "graduation" of 0.0005".

Assuming this means a resolution of 0.0005" then the accuracy can not be 0.0005" because of the quantisation error of +- 0.0005" plus all the other error sources.

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