vernier calipers

[mcolbert]

Hi everyone,

I'm looking to go digital with these primarily for sight / age reasons and wanting to be able to tinker for a long time to come.

I have been told that the Mitutoyo digimatic are reasonably good for accuracy - what are your thoughts / recommendations?

Thanks,

michael 

[Dave In Vermont]

I bought one off Amazon a few years ago for my bicycle work. I already had some extremely accurate ones - quite expensive - but not digital. And found some for around $12. I figured they'd be junk. But I tested their accuracy against my best one. They were spot-on! Tried many different measurements - still perfect.

I suggest taking a look:

http://www.amazon.com/s/?ie=UTF8&keywords=digital+caliper+fractional&tag=googhydr-20&index=tools&hvadid=61984327961&hvpos=1t1&hvexid=&hvnetw=g&hvrand=1178683274492107721&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_38mirelx6q_b

Clear & Precise Skies,

Dave

[Pig]

The Mitutoyo Digimatic callipers are fine, we use them hourly at work, they pass calibration year after year with no adjustments required and they have quite a considerable battery life.

There are 2 main types:-

• One saves the readings and this data can be downloaded and analysed
• The other just shows the measurement on the display

It is an easy mistake to purchase the former without realising and they do cost a bit more. Have a quick check as you might save a few quid.

[Bubbles82]

Machine mart for mine they seem really well made and come in a hard case

[mcolbert]

Thanks guys!

Dave - I'll check the amazon link and see what can be found.

Shaun - I didn't realise that there was a difference - again something to look into.  I probably would prefer something that has memory especially as I'm looking to get stuff custom made for my rig.

Bubbles82 - we don't have a machine mart in this neck of the woods, but your comment did remind me that we do have a specialised mech shop in the next town - it may very well be worth a visit to them.

I have to jump on this soonest as there are four jobs waiting to go; guidescope x 2, adapting a 5 x 4 back for a microscope camera housing and 500 mm f8 and finally adapting a LED housing to a microscope.

Thanks again,

michael

[RikM]

I use Mitutoyo digital callipers at work as well and find them very good.

[Davey-T]

When I was looking there were basically cheap £20.00 ish from Maplin etc or expensive Mitutoyo, I bought the cheap ones as couldn't justify the expense for the others, for the money they are surprisingly accurate checked with feeler gauges.

Dave

[Horwig]

Got mine from Screwfix, but can't really comment on accuracy.

Huw

[Ajohn]

I have tried several but eventually bought Mitutiyo 200mm ones. The extra length is useful and the battery life is a lot better than some I have had. In real terms though they don't compete with a mic if very accurate reliable measurement is needed. I find digital mics a bit heavy and cumbersome compared with the normal ones. It's probably down to making them try to read accurately to 1 um but in practice that level of accuracy is a bit of a joke.

 I've always found it fascinating that 1/10,000 of the supposedly width of king henry's thumb turned out to be a practical unit that can be measured with relatively simple gear. The mm doesn't fair so well.

Some one with eye problems with normal mic's etc might find a simple credit card size fresnel magnifier useful. 

John

-

[mcolbert]

I use Mitutoyo digital callipers at work as well and find them very good.

thanks Rik - so it seems that I'm on the right track with those ones!

When I was looking there were basically cheap £20.00 ish from Maplin etc or expensive Mitutoyo, I bought the cheap ones as couldn't justify the expense for the others, for the money they are surprisingly accurate checked with feeler gauges.

Dave

Davey, I suppose that I am a bit paranoid about accuracy and in the back of my mind I would always be thinking do I need to recheck this with the feelers.  Speaking of which you've reminded me to do a service on them.  

Got mine from Screwfix, but can't really comment on accuracy.

Huw

thanks Huw  all input welcome!

I have tried several but eventually bought Mitutiyo 200mm ones. The extra length is useful and the battery life is a lot better than some I have had. In real terms though they don't compete with a mic if very accurate reliable measurement is needed. I find digital mics a bit heavy and cumbersome compared with the normal ones. It's probably down to making them try to read accurately to 1 um but in practice that level of accuracy is a bit of a joke.

 I've always found it fascinating that 1/10,000 of the supposedly width of king henry's thumb turned out to be a practical unit that can be measured with relatively simple gear. The mm doesn't fair so well.

Some one with eye problems with normal mic's etc might find a simple credit card size fresnel magnifier useful. 

John

-

John thanks for that.  It seems from what you have written it would be better to have two types - dig/analogue (as it were).  It seems that yet again there are different horses for different courses.  I thought that I could just use the one type, but for the sake of accuracy it seems otherwise.

Thanks everyone for the comments it has helped me to think further about my choices!

michael

[Davey-T]

I use a non digital Mitutoyo micrometer for stuff that needs precision the digi' calipers are handy for measuring drill sizes when I cant read the marking on them.

Dave

[woodbob123]

ALWAYS remember to "0" them when taking a measurement very easy to pick them up and forget.

[Ajohn]

If some one wants to measure bores with some accuracy the cheapest option is telescopic guages. There is a technique to using them. Let them spring open in the bore at a slight angle, clamp them lightly and then swing past the actual diameter point, clamp fully, then check that they really are on the diameter. There should be definite resistance as they are tilted through the actual diameter. Then measure the gauge itself .

 Might not make much sense until some one has a set in their hands.

Unfortunately bore micrometers can be expensive, especially the type that centre on the bore automatically.

Digital callipers can be useful for metric imperial conversions - they do get the right. Personally as far as machines go I have stuck to imperial. Reasons relate to Henry's thumb again as surprising as that might sound - accuracy.

John

-

[Ajohn]

ALWAYS remember to "0" them when taking a measurement very easy to pick them up and forget.

Better to clean the anvils of either with a bit of paper - that way the zero on digital callipers will remain correct. The easiest way is to close them fairly firmly on a bit of printer or writing paper and pull it out / move it about.

Not so important when measuring diameters as the contact area is small so pressures are high but it can still make a difference - it will make a difference when the anvils are bought together because of the area and same when measuring across flat surfaces.

John

-

[mapstar]

Cant beat Mitutoyo I have several, digital and ones with scales which are both fine. 

[jbjh]

I've also found with the less expensive micrometers that the auto on/off functions are very sensitive. I remove the batteries when not actively using the tool.

Sent from 80ms in the future

Much peace

Jimmy

[woodbob123]

What I have found is that calliper's can be easily 0ed wrong as you say dirt or gremlins holding jaws apart. worst is if they are used to compare diameters 0 can be set to save all the mental arithmic next time they remember the wrong 0  how do I know??? 

[Ajohn]

If some one doesn't want to spend much it should be worth trying this company - same applies to all of the things they sell. They try hard at the cheaper end.

http://www.arceurotrade.co.uk/Catalogue/Measurement

As usual I have nothing to do with them but they are pretty well known amongst home and small business machinists in the UK.

John

-