Digital calipers - which are the best value?

[PenrithBeacon]

I have three micrometers in my toolbox: 0-1; 1-2 and 2-3. They're hardly ever used because as I get older I need a lit magnifier to read them! The digital calliper is much better.

 

This isn't to say it has its weaknesses. Like all calliper measuring devices, digital or vernier, the beam can suffer from whip which will affect accuracy the larger the workpiece to be measured is. For most purposes in 4mm this is an irrelevance though.

 

Regards

[ianp]

 

The first test is the condition of the tool. Is the glass broken, is anything loose is the tool stiff when you open and close it.

2nd Condition of the jaws. Close the jaws and hold the tool up to the light. Its the ends of the jaws that you are looking at. Are they parallel?

3rd Repeatability. Does the tool always return to zero when you open it out to its full range and then close the jaws. I do this at least three times.

if these seem to be ok then you can start measuring your slip blocks. You don't have any? Well use something else that is constant. You are only checking for wear, the tool will not suddenly change its scale. So find a block of metal, perhaps a coin and measure that. Keep the coin and write on it what you measured it at. Every year check the reading on the tool by measuring the coin again and noting how it changes. You can check along the range by using different size objects. When the reading becomes too far from your first reading then the tool is worn out and you should replace it.

 

 

Thank you. I looked at a set of Draper digital calipers in a local tool merchant. They seemed good (as per your advice) but the shop thought they should price them at about £60. I looked on Amazon and have bought them for £30, including postage, from a tool merchant based in Cheshire.

[Enterprisingwestern]

 

 

Low cost tools have some advantages too - you don't feel as bad if you abuse them (e.g. using the pointy ends of caliper jaws as a scriber when marking out material before cutting).

 

 

The bit that sticks out of the bottom is handy for opening tins of paint too.

 

Mike.

[Rabs]

The bit that sticks out of the bottom is handy for opening tins of paint too.

 

Mike.

 

In fact, if you bend it far enough you can make a hook to carry the calipers with.  Just a shame that it stops them closing fully.

[jackjack]

Moore and wright basic digital caliper buy one get one free approx £41.00.

[Torper]

Moore and wright basic digital caliper buy one get one free approx £41.00.

I've got one of these.  Although I trust (and use) it more because of its branding, it is in fact no more accurate than the Aldi one that I also have.  Both are perfectly adequate for my requirements modelling in 4mm.

 

DT

[jjb1970]

In reality, digital displays on most instruments/meters/clocks are a nuisance, since it is an analogue world.

 

There's a lot of truth there. Years ago I worked on ships where all of the control room instrumentation was analogue dials with a couple of work stations for the alarm system and you could walk through the control room and without really looking check that everything was good just from recognising the positions of the indicators. On more modern ships and in power stations where everything was on PC work stations based around distributed control system architecture it was undoubtedly a lot more compact and efficient and with far greater functionality but what they didn't have was that instant awareness of what the plant was doing simply by scanning the rows of gauges. You had to sit (or stand) and scroll through all the various screens. Another advantage of analogue is that there is a natural damping effect that avoids the irritating tendency of digital readouts to jump around if the process has small variations in the monitored parameters.