Digital calipers

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Harold_V
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Re: Digital calipers

Post by Harold_V »

pete wrote: I doubt there's anything cheaper or more accurate for the money than a good set of telescoping gauges. They can't really tell you the holes slightly tapered or out of round.
Actually, they can, but it requires repeated and careful measurements. One should be able to determine hole size within a couple tenths when they are carefully applied.

H
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John Hasler
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Re: Digital calipers

Post by John Hasler »

pete wrote: The reason the ID side is inaccurate is the tiny flat that's on the measuring face of each ID jaw. So the tighter the radius (smaller hole)the more they span across that radius and can't measure the actual hole diameter.
They could if they had a radius, but as far as I know no one makes any like that. They also can accurately measure small *changes* in hole diameter. Of course they can only measure at the lip.
Mr Ron
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Re: Digital calipers

Post by Mr Ron »

SteveM wrote:
Mr Ron wrote:when a Harbor Freight caliper can do it as accurately and at much less cost.
I have a Mitutoyo and a Horror Freight.

When the Mitu doesn't zero when I close it (it's typically off half a thou), I wipe the jaws, close it and it zeroes.

Steve
I do the same with my Mitutoyo.
Mr.Ron from South Mississippi
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Re: Digital calipers

Post by Rich_Carlstedt »

John Hasler wrote:
pete wrote: The reason the ID side is inaccurate is the tiny flat that's on the measuring face of each ID jaw. So the tighter the radius (smaller hole)the more they span across that radius and can't measure the actual hole diameter.
They could if they had a radius, but as far as I know no one makes any like that. They also can accurately measure small *changes* in hole diameter. Of course they can only measure at the lip.
Actually John, there is such a thing, but my memory denies me the name of the product as we had it back in the 1980's
It was basically a pair of Dowel pins that fastened to the inside of the Caliper jaws. The Dowels ( called "Pins" ) extended beyond the jaws by an inch and were 1/4 " in diameter .They were perfectly parallel to the jaws and you deducted .500 from any reading. We used them on our 12" and 24 " calipers

To replicate this at home, maybe you could super clean your jaws and dowels and then hold the dowels between the jaws tightly and super glue them in place
Sure makes checking bores a fast process

Rich
Mr Ron
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Re: Digital calipers

Post by Mr Ron »

Rich_Carlstedt wrote:
John Hasler wrote:
pete wrote: The reason the ID side is inaccurate is the tiny flat that's on the measuring face of each ID jaw. So the tighter the radius (smaller hole)the more they span across that radius and can't measure the actual hole diameter.
They could if they had a radius, but as far as I know no one makes any like that. They also can accurately measure small *changes* in hole diameter. Of course they can only measure at the lip.
Actually John, there is such a thing, but my memory denies me the name of the product as we had it back in the 1980's
It was basically a pair of Dowel pins that fastened to the inside of the Caliper jaws. The Dowels ( called "Pins" ) extended beyond the jaws by an inch and were 1/4 " in diameter .They were perfectly parallel to the jaws and you deducted .500 from any reading. We used them on our 12" and 24 " calipers

To replicate this at home, maybe you could super clean your jaws and dowels and then hold the dowels between the jaws tightly and super glue them in place
Sure makes checking bores a fast process

Rich
I have an old 6" Helios dial caliper that has rounded nibs for inside measurements. You have to subtract 0.4" from the reading. I bought the caliper about 55 years ago. It was my first caliper . It was made in Germany.
Mr.Ron from South Mississippi
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rudd
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Re: Digital calipers

Post by rudd »

I bought a 6" Mit digital used from a guy, still had the calibration sticker on it. Best 100 I ever spent. Had them for years with no problems. My only gripe is that they read to the ten thousandth. I don't need or want that useless number out there, but they repeat very well. When they don't close to zero, it is invariably a piece of swarf in the inside jaws. Clean it out, everything is fine.
When I need to be close, yes, the mics come out. Much of the work I do I don't need the mics. Also when I am tired I use the calipers for a check to make sure I'm not making a mistake reading the non-digital mics. Measure twice as they say.
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BadDog
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Re: Digital calipers

Post by BadDog »

B&S and Starrett also had rounded tips for ID work. At least they did on their verniers, I have examples of each in different sizes. I even went to check to make sure my memory was correct. The main visually obvious difference with these vs others is that they don't come to a point. IIRC, they are 0.200 when closed, much like is done with inside mics.
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ccfl
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Re: Digital calipers

Post by ccfl »

The very persuasive arguments here have changed my mind. After all, if you go grinding on or modifying the Harbor Freight $10 calipers, you will void the warranty and then not be able to get them replaced if something goes wrong.

But seriously. You guys don't know how to fix things? You don't like to tinker? You don't have more free time than you do money? (If none of those apply and you're too busy churning out parts in your production shop to fuss around with this, then how do you find time to post here?) No, the HF calipers are not usable out of the box. They are not precision instruments. They have edges so sharp you will cut yourself. The adjustments are sloppy and the movable jaw wobbles around and makes for repeatability issues. But, they are made of good hard material and the electronics are solid. The capacitive tape strip that someone mentioned as a source of inaccuracy - oh come on. This is 2017. Parts like that are made by the millions and with stupid accuracy every day all over the world. All of their issues can be fixed with very little effort.

I'd rather pay the $10 and invest some time and end up with calipers that are as accurate, as repeatable, as nice to use, as any $150 caliper out there. And know that I did it myself. But you guys have fun spending money to make yourselves feel better. Sheesh.
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warmstrong1955
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Re: Digital calipers

Post by warmstrong1955 »

Mitutoyo's have a couple of advantages....
One is once you set 'em to zero....they stay there. Wipe & off and check 'em each time, but no zeroing again is required.
Other, like John Evans said, is the batteries last, and I mean years. They last years even if you forget to turn 'em off....for weeks at a time.
My digital quill scale I put on my knee mill, the finest scale China has to offer, goes thru a set of batteries every six months. Doesn't seem to matter if I use the mill a lot or a little. The Horror Freights I have been around, are the same. I don't think they are actually ever off.

Bill
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Frank Ford
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Re: Digital calipers

Post by Frank Ford »

warmstrong1955 wrote:Mitutoyo's have a couple of advantages....
Indeed they do - my Japan-made Mitutoyo calipers have outlasted any number of cheaper brands, which often die from dropping or other causes. Battery life is great, because when the display is off, there's no battery drain. Mitutoyo does offer Chinese-maded ones, though, so it pays to check.

I always insist on genuine Mitutoyo quality, but. . .

Early days might have been a bit different, I'd say:
mitutoyosnap01s.jpg
Cheers,

Frank Ford
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WesHowe
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Re: Digital calipers

Post by WesHowe »

"When I was a lad" (lol) Made in Japan was synonymous with low quality junk... kind of like "made in China" is today. At some point the Chinese will upgrade their products the way Japan did.

The big battle will be keeping the "blueprints" to our newest products out of their copycat hands.
pete
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Re: Digital calipers

Post by pete »

I've read many points by multiple people on multiple threads saying much the same Ccfl. I've even got a 4" and 6" set of cheap digitals around here somewhere I was given for a couple of magazine subscriptions. There simply not worth my time pulling them apart to clean the grinding dust that's still in them and properly deburr them. Not when they'll still eat batterys every 6 months or less no matter how much time I spend on them. As far as them or even Harbour Freights calipers being just as accurate, repeatable, and nice to use? Not a hope, I've handled probably a few dozen different brands of cheap calipers at various stores and not one of them ever came even close to what Mitutoyo provides right out of the box. Lot's I've seen had enough jaw misalignment you could see light through them with the jaws closed.The capacitive tape strip on the cheap ones may well be accurate or not I can't judge that. But it takes extremely well made and very tight tolerance mechanical parts to go along with that tape no matter how accurate it is. And that always costs money no matter where it's made. Some of what Mitutoyo sells is actualy made in China today. But it's made to there exact engineering specifications and quality control. My Mits cost me right around the $200 mark and there still worth every penny of that cost to me because I can be confident in whatever measurement there giving me every time. They never skip a number and repeat every single time. When they don't it's always because of some contamination on the jaw faces as others have said.
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