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Accuracy and Resolution for Digital Caliper: What Can you Recommend?

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I am in the market for some digital calipers for my shop. How much accuracy and resolution do I need? My first job will be adjusting the valves on my CRF250R. I am not sure what else I'll need the calipers for in the future but I want to be sure I have the accuracy and resolution for other jobs too. Obviously, I can just go all out and get some expensive one but I am trying to get one for the least cost but will be accurate enough for dirt bike maintenance jobs. 

 

Thanks!

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I am in the market for some digital calipers for my shop. How much accuracy and resolution do I need? My first job will be adjusting the valves on my CRF250R. I am not sure what else I'll need the calipers for in the future but I want to be sure I have the accuracy and resolution for other jobs too. Obviously, I can just go all out and get some expensive one but I am trying to get one for the least cost but will be accurate enough for dirt bike maintenance jobs. 

 

Thanks!

I'm probably going to receive some hate for this, but harbor freight sells a 6 in. set for around 20$ that would work well. If you want real accuracy, you would need a set of dial calipers, or a set of inner diameter and outer diameter micrometers. I use my 20$ digital calipers quite frequently though and they seem to be accurate enough for this application.

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I use cheap digital calipers and their accuracy and repeatability is very dependent on technique. 

They have a zero reset, and they should be frequently closed to check the display for "zero".

Also do not operate the slide quickly or the sensor will get out of sync.

 

IMO no hand held measuring device is as accurate as a quality micrometer but the digital calipers are so convenient, easy to use, and cheap.

I have several sets of Starrett mics and I've checked my digital calipers with my Starrett standards and found them accurate enough for general work.

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I use cheap digital calipers and their accuracy and repeatability is very dependent on technique. 

 

Technique is everything when measuring with any hand held device.  Less so a vernier micrometer, but even then...

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Skip the digital and get vernier instead. Yes, it takes a minute to understand how to read them the first time, but after that you're good. They don't care about batteries, dirt, dust, grit, oil, gas, or being dropped.

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I am in the market for some digital calipers for my shop. How much accuracy and resolution do I need? My first job will be adjusting the valves on my CRF250R. I am not sure what else I'll need the calipers for in the future but I want to be sure I have the accuracy and resolution for other jobs too. Obviously, I can just go all out and get some expensive one but I am trying to get one for the least cost but will be accurate enough for dirt bike maintenance jobs.

Thanks!

Hi I've been a mold maker for over 30 yrs. so I have a lot of experience. Even the best caliper will never be as accurate as a micrometer. The calipers flex too easily. For the best repeatability and accuracy by a micrometer. Even a cheap one will be more accurate than calipers.

Technique is everything when measuring with any hand held device. Less so a vernier micrometer, but even then...

Thanks everyone! I find your replies helpful!

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I use a caliper for speed and when measuring large items and when accuracy is not critical. When it is critical, I use a micrometer.

For rough numbers, all digital calipers are close enough to not matter.

If you have 10 shims, all marked with the same thickness, they will not be exactly the same, They will be appx +/-.03 of the marked size. Only a mic is capable of accurately measuring that.

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I agree with Gray, cman, and William, I have also worked as a Tool Maker and a machinist. Good mics and practice are the most accurate.

I still have several  sets of Starrett tools and they are the most accurate.  Skill is also important and for measuring pistons and bores I leave that to the pros. 

I use digital calipers, in spite of annual battery changes, for general work because they are convenient. And I find their accuracy adequate for that kind of work, but as previously posted technique and practice is important. Don't measure something with  digital calipers and expect the number accurate closer than 0.005" or 0.1mm. Just saying.

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Why do you need calipers for a valve adjustment? Aren't feeler gauges suitable? Are the shims not marked?

 

IMO, if you really want a glorified ruler, fine, get some vernier calipers.

 

If you want something comparable or even better than digital calipers, get some good dial calipers with 0.000-0.100" dial. I tend toward Mitutoyo, but Starrett, Tesa, Brown & Sharp, Fowler, etc are good. Keep in mind that all of them are really only trustworthy to about ±0.001". With technique, dials can be repeatable to much less than that. Digitals round off the fourth digit for you.

 

If ±0.001 is not accurate enough, then you need micrometers and that's what I would be using to measure valve shims.

 

Harbor Freight and other no-name Chinese calipers are "use at your own risk" IMO. There's no cert of accuracy and unless you maintain some gauge blocks for checking them yourself, you're left with blind trust. I have 6" Pittsburg (HF) and some 4" no-names for beaters that were given to me. They flex more, drag more, drift more, feel like crap, eat batteries, and aren't as repeatable as the 50 year-old Tesas I still use.

 

Properly cared for, calipers are tools and something you'll not have to replace for 30+ years, so why not get something worth having?

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