Topic: Calipers

[amitr0]

What is the difference between a $20 versus a $120 pair or calipers.

Is digital better than analog?

Amy brand recommendations would help.

[bryanj]

Depends what you want to measure, none of them are accurate enough for crank pins, pistons or bores

[Alan F.]

No big difference digital to analog except for batteries and maybe faster reading. I bought a cheap analog Vernier caliper online years back, bought a Harbor Freight model a few years later, they're ok for lots of things if you're not used to higher accuracy.

I guess the determining factor for me was what i use them for. And honestly having more than one around does make life easier.

The measurements BrianJ mentioned can be made by local machinists who are accustomed to very high accuracy, just call around and someone will tell you to come on in.

[RAFster122s]

Precision instruments like micrometers need to be calibrated every now and then, especially if you accidentally drop them. Calipers can be measured too. Back in 84 I worked as a product engineer for TRW Resistive Products Division designing and manufacturing wirewound power resistors… To learn the products and manufacturing I apprenticed in every role to appreciate the complexity and difficulty and challenges of every position in manufacturing. I spent several months working in inspection and receiving and helped institute improvements and get new tools for inspection. Part of those tools were good quality micrometers and calipers to inspect fiberglass braid, measure wire, and ceramic “boats” the resistive elements were encapsulated in after production. The ceramic boats were very hard on the instruments, the analog calipers, digital didn’t exist to my knowledge as calculators were still LED display instead of LCD like today…
The calipers had to be replaced after 9 months as the ceramics wore the tips/ends at a taper. We inspected, measured every inside and outside dimension and slots for the wire terminals of the power resistors. 10k measurements probably or more…
The micrometers were in spec with not appreciable wear seen in photographic optical inspection methods which were and still are one of the ‘gold standard’ type inspection methods.
So, we ordered new calipers every 8 months after that…

That being said, the point is precision instruments need taken care of to not be dropped and if critical it is best to have someone like a machine shop do the precision measurement for you unless you are machining your own stuff. If the later, then pay to have your stuff calibrated every couple years and plan on replacing measuring equipment every now and then…
Most of us don’t need super precision that comes with the more expensive brands. Buying a new set of Harbor Freight calipers every 4-5 years if used modestly and not infrequently will be sufficient… as long as Harbor Freight continues building hobbyist grade fairly accurate calipers.

FWIW

[Little_Phil]

Mitutoyo were considered the business when digital came in. Like Fluke for dvms.
But as already said digital calipers have their limits and are not high precision, but Ok for .001" if used with experience.

[70CB750]

I had a cheapo digital caliper and replaced it with vernier Mitutoyo.   With the cheap one you never knew if it kept zero this time and it was eating batteries too fast.  I also did not want dial caliper - personnal choice - plus I need masurement both in mm and inches because i am a foreigner after all and my engineering degree was n metric.

Spend the money and get a caliper for the lifetime.

[Alan F.]

Thanks for likening Mitutoyo to Fluke, I hadn't thought of that before. I've been multiplying or dividing by 25.4 for a long time now, no need to change yet.

[PeWe]

Do not trust the cheap ones when it comes to important measuring tools.
- Vernier caliper a very often used tool.
- Micrometer not often. It must be reset with help of the accurate piece of steel included.

Agree about Mitutoyo. Go for that brand. I have old ones from the 80's. No batteries !!

Also easy to use converter to get it inch or mm
https://www.convertunits.com/from/mm/to/inches

I do the same with Nm as my wrenches measure and need it in ft lbs.

Just Google  Nm vs Ft lbs

Our Honda are mm bikes

[Bodi]

The cheap digital calipers are not inaccurate as a rule, but they eat batteries. In order to save the zero position, digital calipers need to keep some memory powered continuously. Mitutoyo and other top tier brands somehow do that with much less power and the same battery lasts 10 times longer.
Remove the battery if one is rarely used. Once dead, after a year or two the battery can leak and corrode the innards.

[rotortiller]

For general measuring cheap is fine. Often all you are measuring is IDs and ODs and comparing for clearances (difference), the tools accuracy is fine in this case being under tasked. However when checking an actual dimension to an engineering dimension cheap tools can fall short especially  at extended tool travel. Also correct tooling is desired for the same reason and is why a micrometer or bore gauge does a better job for the intended situation. Dial indicators used to measure run-out or ignition piston position BTDC can be cheap as old fux.  That being said accuracy 'is often all in the wrist action'. lol

[bryanj]

Trouble is for cranks, rods and casingsHonda used air gauges accurate to1/1000 of a mm or about half a thou if my maths is correct

[PeWe]

The old working good brands models  might be found for not that much when later models have batteries.

I understand those who lives in the inch world and need to know the result in both mm and inch by pressing a button.

My Mitutoyo calipers from the  80's will work fine even after the total collapse when batteries are difficult to be found.

[Alan F.]

The old working good brands models  might be found for not that much when later models have batteries.

I understand those who lives in the inch world and need to know the result in both mm and inch by pressing a button.

My Mitutoyo calipers from the  80's will work fine even after the total collapse when batteries are difficult to be found.

+1

[MauiK3]

I have my grandfathers 0 to 1” Starrett micrometer, I think it’s close to 100 years old.
Works great.
Starrett, Mitutoyo are great brands.
A digital caliper is ok for getting an idea of the size of something but when I measured up my cam lobes and journals for the Z1 today it was Starrett and Mitutoyo to the rescue.

[Alan F.]

Digital are also good for taking pictures of a measurement, like on eBay etc.

[70CB750]

Digital are also good for taking pictures of a measurement, like on eBay etc.

And the easiest way to go from mm to inches.