Caliper woes....

[jcwit]

But we'll use a mill with a readout??????????????????????????

[WallyM3]

If you have good tolerance or ball-screw lead screws....why not?

I have a 5-digit B'port that still does what it was intended to do w/o optical linear measurement devices.

Actually, I know I'm blessed. Most are too worn.

[JSnover]

But we'll use a mill with a readout??????????????????????????

Bingo!

[6bg6ga]

It doesn't take a $200 set of calipers to make a simple measurement. I've used all brands and types of calipers over the years. I've even used the $4.00 plastic calipers and they all measure fine. Simple steps like not trying to shut them fast sometimes does make a difference. The early digital calipers didn't track well if closed too fast. Keep them clean if using an exposed track and dial caliper and some of the digital calipers also have a track and gear setup. They came up with the dial and digital for those too lazy to use a caliper that doesn't have either the dial or digital display. Sometimes old school is the best.

[Motor]

Maybe I dont understand what you're saying. In the last week I've seen +.005 -.000, +.000-.005, and +.003-.000"
Ive never seen a particular method called out for measurement. In my own experience the customer doesn't care how you measure, they care that everything is the right size.

I guess you never did work for Sikorsky. They tell you what to measure every single dimention with and its usually the least accurate method allowable.

Quote:But we'll use a mill with a readout??????????????????????????

Yes but we all post inspect too, don't we?

[montana_charlie]

What do you use and why.....

Dial caliper, because the readout is analog.

CM

[6bg6ga]

Types of calipers

All will be accurate depending on the operator.

Attachment 118956Attachment 118957Attachment 118958Attachment 118959I have shown el cheapo plastic calipers, dial, digital, and all metal calipers. All will measure correctly in the right hands. Expensive ones will not measure any better than the cheapest plastic ones.

[6bg6ga]

I've found that bullets are a good item to use to test when one doesn't have machined blocks of specific sizes to use.

Pictures of Hornady XTP 10mm .400 diameter as tested with a mic.

Checked with two calipers.



Attachment 118961Attachment 118960

[6bg6ga]

Dial caliper, because the readout is analog.

CM

I like the old school calipers with neither a dial or digital read out. Nothing to get out of whack.

[WallyM3]

As in "Vernier"? Gettin' too hard to see.

[jcwit]

They came up with the dial and digital for those too lazy to use a caliper that doesn't have either the dial or digital display. Sometimes old school is the best.

Or for those of us whose eyes are too old to use any more.

But I guess that's a personal problem, for me anyway.

[6bg6ga]

Or for those of us whose eyes are too old to use any more.

But I guess that's a personal problem, for me anyway.

I had the young people in mind when I made that comment. Some of them don't understand how to read a standard caliper that has neither a dial or digital read out. As for myself I have to depend on a jewelers loop or big stationary magnifying glass to read the thing.

[jcwit]

I had the young people in mind when I made that comment. Some of them don't understand how to read a standard caliper that has neither a dial or digital read out. As for myself I have to depend on a jewelers loop or big stationary magnifying glass to read the thing.

I was agreeing with you and stating my shortcomings from being old.

I'm still blessed IMO.

[dragon813gt]

So what's wrong w/ making it easier to read?

[theperfessor]

I have had several digital calipers and have given or thrown away every one. My digital readout on my mill is always on and stays plugged in to power, my digital calipers always seemed to have low or dead batteries. I now use a 6" Starrett dial caliper as my primary shop caliper, and when I took on my apprentice I gave him a 6" Mitutoyo dial caliper. I have several HF/Enco brand dial calipers that I keep in the gun room, my office, and a traveling tool box.

I also have a 6" Craftsman vernier that is still accurate after forty years of use, and a 24" vernier that paid for itself the first time I used it.

Two problems with dial calipers: Open and close them gently, I've seen the needle spin right of the stem when a student slammed the jaw closed. And don't let chips get on them, a little chip caught in the gear rack can ruin a unit.

One problem I've seen w/HF calipers is the jaws aren't parallel and the indicated value changes with pressure. Not good. Otherwise they are usually accurate enough for gun room use.

[6bg6ga]

I was agreeing with you and stating my shortcomings from being old.

I'm still blessed IMO.

I was trying to point out that in todays world its hard to find someone that can even read a plain caliper or micrometer that doesn't have a dial or digital read out. When I was in inspection all I had was the plain stuff because the digitals were junk and the dial calipers were easily wrecked if dust and or dirt got into them.

[JSnover]

I guess you never did work for Sikorsky. They tell you what to measure every single dimention with and its usually the least accurate method allowable.

Then what does it matter? Sounds like they just want you to tell them a good story. In the end it won't be an issue until you start turning out junk and that won't be their fault, it will be yours no matter how you measured.

[Motor]

Then what does it matter? Sounds like they just want you to tell them a good story. In the end it won't be an issue until you start turning out junk and that won't be their fault, it will be yours no matter how you measured.

You sure have never done work for the DOD. Everything is documented and all of the equipment has serial numbers and the serial number of the instrument is written on the inspection report along with the dimention and of course your QA stamp. It's not a story and if you lie and make false documents you can end up fired or in federal prison.

This is not just for the QA department. Every technition has their own pass & fail stamps and fills out the inspection report.

[WallyM3]

Always obtain the best tools that you can.

Not all that complicated and a good rule to apply to many things.

Gauges are generally used in repetitive inspection, no?

[alamogunr]

I'm not a machinist and have never played one on TV, but I know how to read a vernier. I have 3 micrometers, 2 standard and one blade micrometer, all 0-1" The one I normally use is a Brown&Sharpe. I have a 6" Mitutoyo dial caliper that I use when I'm in a hurry, mostly for OAL measurements.

The B&S and Mitutoyo came from my former employer. Over time everyone wanted digital and these just sat in a drawer. Whenever I needed a mic or caliper, these were what I was given. They work for me. I would not argue with anyone about the suitability of calipers for most measurements. I'm just not confident using them in place of a micrometer.