Dial caliper trivia

[rustyknife]

If you are ever on a game show, and the host asks you how many times you can drop a dial caliper in a day before it is ruined....the answer is one. Second time is a gonner ;D

Now accurate within + or - .002

It said shockproof, I need bounce proof perhaps

Haha

With kind regards and butterfingers,

Eric

 

[Russel]

That is one of the reasons that I prefer to use vernier calipers. Unfortunately, vernier calipers require most of us that are older to use magnification.

 

[Tin Falcon]

I would not rely on calipers to be more accurate than +-.002 inches anyway.
Tin

 

[RonGinger]

I would not rely on calipers to be more accurate than +-.002 inches anyway.
Tin

A friend of mine calls them 'very nears'

 

[mike os]

A friend of mine calls them 'very nears'

which is a bit unfair... they are only meant to be for a limited accuracy, and therefore limited application... end of the day even a high end micrometer is only "very near" if working in angstrom units. If a part needs to be +-1/16 even a "cheap" mic is a bit overkill .

 

[rustyknife]

Well....let me describe it better. Accurate is not so much of a concern with me NEARLY as much as consistency.

If I measure a part that's say .500" and if it measures .002 off at .498" that's completely fine with me as long as it measures .498" EVERY time. It must be consistent.

But if I measure it 5 times and get everything from .502-.498 I'm not going to be very happy.

I will of course break out a mic if I need accuracy, but I had this dial caliper for most likely 7 years and used them alot so I had a pretty good feel for this set, I could measure things very consistently. Now they are no longer consistent

Regards,
Eric

 

[Tin Falcon]

Eric I can relate. Like and old pair of comfortable shoes. I have a pair of grizzly digital s that I purchased at a tent sale probably close to 10 years ago they are my hands down favorites I have several dial calipers and several digials they all work but the grizzly have the best feel.
As far as repeatability I can see where that would drive you nuts as well. guess it is time to find a new measuring friend for the shop.
Tin

 

[Russel]

I would not rely on calipers to be more accurate than +-.002 inches anyway.
Tin

I've heard and read this countless times, but in my personal experience I find that I can measure consistently down to less than one thousandth. I frequently measure a part with my calipers, machine off a few thousandths and remeasure with my caliper finding that it agrees with my DRO and micrometer down to a couple tenths of a thousandth. I use the same caliper and use the same method and feel to take the measurement which helps with consistency. Of course, if it is a critical measurement I use a micrometer, but I find that it just confirms my caliper measurement.

 

[mklotz]

I have to agree. Assuming a quality (eg, Mitutoyo), well-adjusted dial caliper, if you can't measure better than ±0.002", you seriously need to revisit your technique.

My veteran Mitutoyos have NEVER been off that far and they've been in continuous use for more than thirty years. My electronic Mits are just as good. With either I can reliably and repeatably detect sub-thousandth variations, confirmed with a micrometer.

Measuring with calipers requires a lot of thought about technique if you want accuracy. Keeping the jaws properly aligned is difficult when measuring something on the lathe - which is why I always use a mike for that case.

 

[rake60]

I own two Mitutoyo 6" dial calipers.
Both of them have been dropped several times and I've had to recalibrate them.

One of them was accidentally left on the table of a vertical boring mill I was running at
work and it had to be sent back to the factory for repairs.

If I'm going for a .0005" bearing fit, I'll use a micrometer.
If the spec has a .001" tolerance, I'm using one of my "Mit" Calipers.

Accuracy does not come from a tool, it comes from the user of the tool.
I'm not claiming to be some kind of a accuracy wizard machinist!

When I miss a size, and that happens as often as it does to ANY machinist, it's not because
the measuring tool was giving a wrong answer.

+/- .002" Is more than close enough for 90% of what I DO in my hobby shop.
I DO occasionally check the sizes against a micrometer, just for verification.
I've never found it to be more than .0005" off.

Take proper care of a dial caliper and it will not lie to you.
Spend the big bucks on a state of the art digital caliper.....

You're on your own!

Rick

 

[kevin45]

I'll use dial calipers as "reference only". If I want an accurate measurement, I will use my mics. To me there is too much error in calipers all for the fact that there are two adjustment screws at the top pushing on to a brass shim. If one day you ate your Wheaties, you may put a tick more of thumb pressure on them than yesterday. I rely on them less using the points on an inside measurement. I was mentored on using mics for accuracy, and calipers for reference, and the ones I have mentored I have taught the same way.

 

[Swifty]

I have an old dial calliper that I use for general work, just have to be careful that there is no dirt in the rack that the gear runs on as it can jump 0.5mm if there is something in the rack. Have a few vernier calipers, but the eyesight isn't as good as it used to be, so rarely use them. Anything that requires better measurement, I will use a digital caliper or micrometer.

Paul.

 

[Hopper]

You have to be careful with digital calipers too. I found mine (Kinchrome brand, cost about $100 but doubtless made in the same Chinese factory as all the others) can read a couple of thou out at certain areas and spot on at others. So ok for machining something to fit a part that was measured with the same calipers, but for any precision work or to drawings etc I still use my old faithful Mitutoyo mic and old-style vernier (with magnifying glass these days!).

 

[jwcnc1911]

Wow. Very varied opinions on calipers here. Obviously there is an art and technique to using any precision instrument from calipers to a CMM. Personally, I have 10 to 12 pairs of calipers. My favorite being a never dropped (I'll drop'em now) set of Mititoyo digitals that set me back about $240usd. That price hurt but I'd put them up against any dinky chinese mic most "hobby" folks use any way. I also have a set of B&S dials I got way back in trade school that I'd bet my whole shop on the the half thou. Furthermore, I prefer gage pins or blocks when ever possible. This way you know what you have regardless of hold, pressure or other variables.

If you screw down on mics your accuracy is gone. Same with calipers, easy on the thumbwheel. Calipers in my opinion are quick. If you need absolute precision you need to set up on a surface plate with blocks and use actual metrological methods. Otherwise your always at the mercy of how you've learned to do things. Which, honestly for me is often slightly wrong but still effective enough for my purpose at hand. When I need higher precision the CMM steps in. It's capable of .002mm over 2000mm.

Speaking of metrology, every one's method reminds me of that opinions saying:

Opinions are like buttholes, everybody has one.

 

[ShopShoe]

Best advice I ever got was on this forum from Bogstandard (I believe) when he was posting here: Don't use the thumbwheel. Squeeze the jaws closed on the work with two fingers. That and and re-zero every time before reading.

I use the cheap HF 6-in. digital calipers for general checking: If I drop them I'm out $20.00, or less with a sale or a coupon. I have another one in the house just in case. I also have a dial caliper if the batteries die.

If I need to be accurate, I use a micrometer, sometimes I double-check and compare in an effort to refine my measuring skill.

When I have extra money (rarely) I plan to upgrade to Starret and Mitutoyo as I can.

By the way, I bought a metric micrometer for when I work in those units and I prefer that to the switchable scale on the digital calipers. So much simpler to just use metric rather than do conversions.

 

[Woodsworks]

I own two identical digital verniers, one I trust absolutely to measure consistently, while the other can be made to add or subtract 0.002" depending on how you hold it - doesn't fill you with confidence, does it? Nevertheless, I still prefer the verniers over a mike, much easier to see where the jaws are touching so I know I'm measuring the right bit. I just gently rock the calipers to and fro, looking for the lowest reading as the jaws 'pass' the narrowest point. Regards, Paul W., Whangarei, NZ.

 

[kf2qd]

If I am doing work that requires a batch of parts to be made the same (production) or to fit some other part (like a piece of Thompson ground shaft) then I will use my Mics. Otherwise, for one off stuff I have no problem with the calipers as I am probably going to have to do a little polishing anyways as my mini-lathe does have its limitations...
Not everything I make has to be to 2 tenths...

 

[motoseeya]

I'm an old cabinet maker and when I need new rulers for the shop I would go to store and dump out a box and go throw them to find six that would read the same sometimes it would take two boxes. I have been to get calipers and found that it's hard to find two that will read the same every time on the same piece. Now don't get me wrong I don't get the high dollar
ones I don't need them for hobby work. Just saying two people with to different sets of calipers will have two different readings most of the time. just my two cents.

 

[barnesrickw]

For woodworking, I try to use fixtures and stops for repeatable results when I mass produce parts. Not sure if it can be applied to metalworking.

 

[Heffalump]

For me it has to be a vernier caliper all the way. But at 26 years of age I can see that I have the advantage of young eyes (sorry chaps)