Taking it up a step---

[Brian Rupnow]

Up until this point in my engine building career, I have depended entirely on a 1" micrometer, a 2" micrometer, and two analog Verniers of questionable quality to measure everything that I machine. I've decided to take my game up a notch, and have ordered a micrometer depth gauge and an internal micrometer that measures inside diameter from 1" up to 2". They are both in shipment to me, and I must say I'm a bit excited about it.----Brian

 

[ShopShoe]

You'll be glad to have them.

ShopShoe

 

[stevehuckss396]

I thought you were going to announce your new V16 build! Haha!

Inside mic is great. I started collecting them on ebay. I can now measure 1/8 - 3 inch. You will love it.

 

[Charles Lamont]

I find my depth mic very useful. I too have collected much of my measuring gear on ebay.

 

[Toymaker]

Maybe it's because I'm an old electronics engineer that I much prefer my digital calipers over micrometers; with calipers you get outside, inside, and depth measurements, all in one tool This past October, I bought a new Mitutoyo 0-6" off eBay for $45 to replace my failing, much cheaper Chinese no-name-brand caliper. Mitutoyo isn't the most expensive brand out there, but it's plenty good enough for what I do.

 

[Jasonb]

I'm not any kind of engineer but use my digital callipers for most things, the 1" mic only comes out occasionally, the depth one even less. As we are not making for mass production I tend to make one part to "fit" another and you can't buy a tool to measure what" feels" right.

 

[GreenTwin]

I'm not any kind of engineer but use my digital callipers for most things, the 1" mic only comes out occasionally, the depth one even less. As we are not making for mass production I tend to make one part to "fit" another and you can't buy a tool to measure what" feels" right.

I distictly recall when I started to try and formally learn machining that I used digital calipers for every measurement, and my measurements were all way off, to the point of the part not being usable.
I was aware of micrometers, but did not realized how inaccurate some digital calipers can be.

So now days I use the digital calipers to get in the ballpark (within about five thousands), and then use the micrometers for a check on the remaining light cuts.

I like digital calipers a lot, but the battery life is not very good.
I have resorted to wiring an a AAA alkaline when the voltage matches.

I am not a formally trained machinist (far from it), but like Jason, I can get a good fit on parts for small engines.
I have a set of over and under reams too, so that is a big help.

.

 

[trlvn]

an internal micrometer that measures inside diameter from 1" up to 2"

What device are you getting, exactly? A 3-prong hole micrometer?

A 2-pin mic that can measure on the inside or outside?

Or a bore micrometer?

Something else?

Craig

 

[Richard Hed]

I'm not any kind of engineer but use my digital callipers for most things, the 1" mic only comes out occasionally, the depth one even less. As we are not making for mass production I tend to make one part to "fit" another and you can't buy a tool to measure what" feels" right.

I use calipers for most measurements--that is, until I get near my final cut on a precision part. Most cuts don't require precision- 1 or 2 thous is fine which is all I trust a caliper for. But when I have the need for .001 or less, is when I get out the trusty micrometer.

BTW, the only thing I don't like about mics is the way they read: that is, the threads on them are 40TPI which makes the readings into 25 thou increments. How many times have I had to add .013 to some other number to get the right amount? I have come up with another system that users 50TPI and so you will have 5 increments in 100thou rather than 4. This makes it so you will be adding in 20 thou increments instead of 25, for instance, try adding 13 thou to 60 thou--easy peasy. That's one reason I like electronic calipers and mics, you don't have to add. The electronics have other functions too. Even so, I get very irritated when I have to chnge gthe battery.

A 50 TPI actually gives a small amount of higher accuracy too.

 

[peterl95124]

a friend of mine is considering getting started in this hobby,
he started looking at lathes and was asking for advice,
one bit of advice I gave him was that when I started I spent
roughly 1/3 on a lathe, 1/3 on a mill, and 1/3 on tooling and measurement instruments,
(mine were "relatively" inexpensive bench top machines,)
and that materials, tooling, and measurement instruments are an ongoing,
never ending, expense.

even after 30 years I still acquire the occasional new, or new-to-me, measurement
instrument, the most recent being a very sparse collection of gauge blocks so I
can quickly and easily verify my dial calipers in the region I'm trying to measure.

anyway, does anyone else think the 1/3-1/3-1/3 estimate is worthy of being elevated
to a rule-of-thumb status

 

[Brian Rupnow]

TRLVN--Getting one like the center picture.---Brian

 

[Richard Hed]

a friend of mine is considering getting started in this hobby,
he started looking at lathes and was asking for advice,
one bit of advice I gave him was that when I started I spent
roughly 1/3 on a lathe, 1/3 on a mill, and 1/3 on tooling and measurement instruments,
(mine were "relatively" inexpensive bench top machines,)
and that materials, tooling, and measurement instruments are an ongoing,
never ending, expense.

even after 30 years I still acquire the occasional new, or new-to-me, measurement
instrument, the most recent being a very sparse collection of gauge blocks so I
can quickly and easily verify my dial calipers in the region I'm trying to measure.

anyway, does anyone else think the 1/3-1/3-1/3 estimate is worthy of being elevated
to a rule-of-thumb status

When ever I thimpfk of 'rule of thumb' I can't help but thimpfk that a glove on the hand is important: a couple years ago my daughter and I were welding and it came to pass that I had to hammer on some part with mighty blows (with Thors original stone hammer, no less). I didn't have a glove but the mighty blows were so close to my thumb, I stopped and considered my 'thumb'. Smartly, I decided to use a glove and . . . you got it . . . I smashed my thumb but I know it would have been so much worse without the welding glove. Didn't split the skin, jusst a bruise, but without the 'rule of thumb' glove, it certainly would have split the skin and maybe even broke some bone, afterall, it was Thor's Stone.

Speaking of Thor's Stone, here is a good one, and it's true: My dad's name is Thurston Johnson, there were two Thurston JoHnson's in Thurston County (the Soviet of Washington). My dad acciddentally paid the other Thurston Johnson's land tax, and had trouble fixing that. Dad also bousght our property from Bob Thurston in Thurston County. Yay Thor, the one true God!

 

[mfrick]

So when I was teaching I would tell my students that they could not use a cailiper until they had a good handle on using the outside and inside micrometer alnong with a depth micrometer. I would introduce the caliper to them once they had mastered the Micrometer. The results of doing this was students who could make parts to size .
Mike

 

[Gordon]

I have an inside micrometer like Brian has on order and have not found it to be very useful I have better luck with snap gauges. I have two depth gauges. I bid on two of them on eBay and got both of them. One I got for about $10 and the other for about $25. I have not used them very much because for many depth measurements the dial caliper is close enough. Like others have said I use the dial caliper on things until I am within about .005 and then use the micrometer if greater accuracy is required.

 

[delalio]

Hey Gents,

Very interesting thread. I am a hobby model engineer. Ive never worked in formal mechanical engineering or toolmaking.
Anyway, im fascinated by vintage tools, and for the last 4 years have been collecting Moore and Wright tools from 1940s - 1990s. I think i have about 250 items.
However, for my model engineering work, i typically only use 3 tools when working on the lathe...
A 0-25mm (0-1in equiv) micrometer for accurate measuring
A 0-150mm vernier caliper, for quick measuring and roughing out,
A dial gauge if i need to use the 4 jaw chuck.

A lot of the books for projects i do, as others have said, recommend many of the parts are made in a specific order like others have said, so accurate fitting parts can be made without needing loads of different tools.

I have one of each tool in the catalogue, and I basically use 2 of them.

A good mic costs less than 15£ on ebay. Best money ive ever spent.

Just my 2c.

Del

 

[Apprentice707]

It seems that I am not alone in using my digital caliper to establish a dimension to within 5 thou and then homing in using a micrometer. When I need to turn a shaft to a standard dimension I use a gauge to set the caliper and the zero the scale I can then see easily how much metal to remove until I am within the 5 thou.

I have various micrometers up to 6 inches, internal micrometers to the same, and a depth mike to 6 inches. In truth, I only use the 0-1 inch and occasionally the 1 - 2 inch. the others I have "Just in case" a philosophy I follow with many other things. I also find telescopic gauges, small hole gauges, and a digital scribing block very handy.

Recently I obtained a digital DTI which I find very accurate and easier to use than my trusty Starrett analog DTI which I have now retired to the back shelf.

Speaking of measuring things I realised the other day that I don't know how to turn a spigot to a metric dimension, a gap in my knowledge, or a denial of things metric and foreign.

A Happy and Prosperous New Year to all and long may we create swarf.

B

 

[ajoeiam]

So when I was teaching I would tell my students that they could not use a cailiper until they had a good handle on using the outside and inside micrometer alnong with a depth micrometer. I would introduce the caliper to them once they had mastered the Micrometer. The results of doing this was students who could make parts to size .
Mike

An 8" digital vernier was my first measuring tool.
Found that I could influence the measurements far too much. (Could change the measurement by an easy 0.002"!)
Measuring with the tool not totally square to the bore (ID measurement) was also far too easy.
Also got bit real good making a bearing fit shaft one day and that taught me the crucial effect of temperature on measurements.

I have collected a few measuring tools - - - but it always feels like 'never enough' - - - LOL.

Wish I would have exposed to good instruction at the beginning of my learning machining rather than well into it.
Likely would have made a bunch of things much easier!! (And likely more accurate too - - - grin!)

Making to fit is not a bad way to work but not very useful when you start dealing with stuff that weighs enough or is not easily movable or doesn't fit onto the lathe - - - then you absolutely must be able to measure well!

 

[Richard Hed]

An 8" digital vernier was my first measuring tool.
Found that I could influence the measurements far too much. (Could change the measurement by an easy 0.002"!)
Measuring with the tool not totally square to the bore (ID measurement) was also far too easy.
Also got bit real good making a bearing fit shaft one day and that taught me the crucial effect of temperature on measurements.

I have collected a few measuring tools - - - but it always feels like 'never enough' - - - LOL.

Wish I would have exposed to good instruction at the beginning of my learning machining rather than well into it.
Likely would have made a bunch of things much easier!! (And likely more accurate too - - - grin!)

Making to fit is not a bad way to work but not very useful when you start dealing with stuff that weighs enough or is not easily movable or doesn't fit onto the lathe - - - then you absolutely must be able to measure well!

What do you mean by "digital vernier"? No such thing, I thimpfk.

 

[Brian Rupnow]

Digital vernier needs batteries and a read out. Analog verniers have a rack and pinion driven dial.

 

[Richard Hed]

Digital vernier needs batteries and a read out. Analog verniers have a rack and pinion driven dial.

I thimpfks you mean a "caliper', as a vernier is one of those old fashoned measurer that has 10 marks on one side of a slide and 11 marks on the other. Maybe you have a "digital vernier" on a micrometer. Do you have a photo? I'm confused