Arrrggghhh! - Metric Stuff Up!

Bloody metric measurements - great system, couldn't and wouldn't argue against it. But.....

Consider this scenario, good people. Ducted heating furnace in the roof was having a good go at coming through the ceiling (being a skilled metalworker, and a RCM lurker, I knew straightaway something was wrong..) Turned out to be crappy install job, vis

1.Vent pipe not sealed properly (so it leaked) 2.Was sitting on a sheet of particle board crap stuff so it rotted through 3.No drip tray set up for stuff ups.

So. Decided to get a drip tray made, its a metric world, so did it all in Metric so as to give the order for the tray to the local plumbing supply place. Measured L by B, added 10mm each side for the folded lip, and put the order in. Picked it up, thought "Mmmm..."

Seems I had stuffed up the decimal point in my metric calculations - was 200mm wider than required (length was stuffed too, but that was OK

- was room up in the roof cavity) so, couldnt get the bastard up through the access hatch into the roof. So, had to cut it down - heaps of work...

The Moral - I cant think in Metric, cant visualise in Metric, cant look at metric measurements and think "nah, no way - too wide/long/ narrow thick etc etc"

How you guys cope - bloody sick of doing this...

Andrew VK3BFA.

Reply to
Andrew VK3BFA
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Metric sucks, and I don't give a damn about the arguments to the contrary.

Those of us that were groomed to work in the Imperial measuring system have no issues with how it works. I know what a yard is, as well as I know what a foot is, or one ten thousandth of an inch, for that matter.

As you alluded, when someone makes mention of a size, I have an instant visual idea of it's general size. Not so with metric, which I must convert to Imperial in order to get a perspective.

Is it any wonder that the US has resisted the conversion to metric?

Harold

Reply to
Harold & Susan Vordos

For approximate stuff just think of 25 mm = 1" , 100 mm = 4" , 200 mm = 8" etc.

In the US, in my field of optical engineering, lens elements are always specified in mm, but the lens housings that hold them are usually specified in inches. This is because lens fabrication in the US was pioneered by German immigrants, so lenses were always done in mm or meters. However most engineering firms STILL do mechanical design in inches. This fact amazes optical engineers from Japan and Europe, especially since tolerances on the internal bores can be as small as a few .0001" . Or is that a few microns? Or is that a few micrometers (as a millionth of a meter is known in the rest of the world)?

One good thing about inches is that it forces you to learn fractions. Any (good) carpenter in the US can add 2-9/16 + 3/4 in his head. I have seen Ph.Ds from Europe struggle with this for some time with paper and pencil.

Reply to
anorton

Andrew VK3BFA on Mon, 29 Nov 2010 23:07:18 -0800 (PST) typed in rec.crafts.metalworking the following:

Layout in Imperial, convert to Metric at the last.

Reply to
pyotr filipivich

Many years ago I suffered the same thing, but time and practice makes it better. I can now think metric without having to convert to Imperial for perspective. However, it is important to note that some things are easier to accomplish with Imperial than Metric, but that knife cuts both ways. So now I use both depending on the task at hand. I have half my machines as Metric based and the other half Imperial based. So far, I haven't suffered errors of system confusion. Steve

Reply to
Steve Lusardi

Bloody metric measurements - great system, couldn't and wouldn't argue against it. But.....

Consider this scenario, good people. Ducted heating furnace in the roof was having a good go at coming through the ceiling (being a skilled metalworker, and a RCM lurker, I knew straightaway something was wrong..) Turned out to be crappy install job, vis

1.Vent pipe not sealed properly (so it leaked) 2.Was sitting on a sheet of particle board crap stuff so it rotted through 3.No drip tray set up for stuff ups.

So. Decided to get a drip tray made, its a metric world, so did it all in Metric so as to give the order for the tray to the local plumbing supply place. Measured L by B, added 10mm each side for the folded lip, and put the order in. Picked it up, thought "Mmmm..."

Seems I had stuffed up the decimal point in my metric calculations - was 200mm wider than required (length was stuffed too, but that was OK

- was room up in the roof cavity) so, couldnt get the bastard up through the access hatch into the roof. So, had to cut it down - heaps of work...

The Moral - I cant think in Metric, cant visualise in Metric, cant look at metric measurements and think "nah, no way - too wide/long/ narrow thick etc etc"

How you guys cope - bloody sick of doing this...

Andrew VK3BFA.

We have been metric for a long time in Canada, and I still can't relate to anything but temperatures! I have no concept of distances in Km, and have to translate to Imperial. Having owned a watch repair shop, I am ok in a few hundredths of a MM, but tend to think in thousandths of an inch.

Once when I was given directions to a staff party, the lady said it was 3 Km past a certain point. I asked "how far is that"?

I am 70 years old, and will probably never fully adapt to metric!

So there you are!

Steve R.

Reply to
Steve

Bloody metric measurements - great system, couldn't and wouldn't argue against it. But.....

Consider this scenario, good people. Ducted heating furnace in the roof was having a good go at coming through the ceiling (being a skilled metalworker, and a RCM lurker, I knew straightaway something was wrong..) Turned out to be crappy install job, vis

1.Vent pipe not sealed properly (so it leaked) 2.Was sitting on a sheet of particle board crap stuff so it rotted through 3.No drip tray set up for stuff ups.

So. Decided to get a drip tray made, its a metric world, so did it all in Metric so as to give the order for the tray to the local plumbing supply place. Measured L by B, added 10mm each side for the folded lip, and put the order in. Picked it up, thought "Mmmm..."

Seems I had stuffed up the decimal point in my metric calculations - was 200mm wider than required (length was stuffed too, but that was OK

- was room up in the roof cavity) so, couldnt get the bastard up through the access hatch into the roof. So, had to cut it down - heaps of work...

The Moral - I cant think in Metric, cant visualise in Metric, cant look at metric measurements and think "nah, no way - too wide/long/ narrow thick etc etc"

How you guys cope - bloody sick of doing this...

Andrew VK3BFA.

We have been metric for a long time in Canada, and I still can't relate to anything but temperatures! I have no concept of distances in Km, and have to translate to Imperial. Having owned a watch repair shop, I am ok in a few hundredths of a MM, but tend to think in thousandths of an inch.

Once when I was given directions to a staff party, the lady said it was 3 Km past a certain point. I asked "how far is that"?

I am 70 years old, and will probably never fully adapt to metric!

So there you are!

Steve R.

Reply to
Steve

I did my engineering trade when Australia was changing from imperial to metric ,so I was using both systems .Most of the engineering drawings had the metric dimensions as the main , and the imperial placed in brackets above the metric ones.

I have both metric and imperial micrometers and depending on the project and where the idea comes from ,I will follow the easiest route. My lathes are imperial and my mill is metric. I don't have any problem using both systems . I must admit I find the metric system easier to use as there are no fractional measurements to deal with .

Reply to
Kevin(Bluey)

I memorized a few exact and approximate conversions and work out from them.

The exact ones are:

1" =3D 25.4mm, and 1mm =3D 0.03937" 1 pound =3D 453.6Kg, 1Kg =3D 2.205 Lbs

The US and Britain adopted the 25.400000mm Canadian inch after WW2.

I trained as a chemist and thus use only metric for liquid weights and volumes. I'm comfortable with both for linear measurement and prefer US screw threads, especially in aluminum castings.

For rough estimates:

3/16" =3D 5mm, 5/16"=3D 8mm, 7/16"=3D11mm, 9/16=3D14mm, 3/4" =3D 19mm, 20mm= ~=3D 0.8". One micron is 1/25 of 0.001" or 40 microinches, or nearly half of a division on an indicator that reads to tenths. 25mm =3D 1", 300mm =3D 1 Ft =3D 1 nanosecond =3D 1GHz Electricity travels half as fast on a circuit board. One horse-measuring hand ~=3D 100mm 3 kilometers ~=3D 2 miles 1 fortnight ~=3D 1 million seconds

The rough estimates are good for gently reminding some Ph.D. that I can't stuff 10 lbs into a 5 lb bag.

jsw

Reply to
Jim Wilkins

ABSOLUTELY !!!!! ...lew...

Reply to
Lewis Hartswick

Skip the conversion?

Reply to
CaveLamb

At the hardware store, you can't even buy a decent 1 digit thick

2 cubits, 3 palms by 5 cubits, 1 palm, 2-43/64 digits sheet of plywood anymore.

Those nimrods just stare and smirk as if you've just started spouting gibberish!

In my day, a cubit was always 6 or 7 or 8 or 9 palms in length. Well, never more than 37 digits anyway.

Damn straight, Harold.

The sooner we get back to digits and cubits, the better.

--Winston

Reply to
Winston

I much prefer to express my van's fuel economy in "Furlongs per Hogshead".

Reply to
Tom Gardner

I can visualize metric up to about 9mm or so... after than I have to convert to imperial to visualize.

Reply to
Pete C.

Why do you need fractions? I just work in decimal inches, rounded off to an appropriate number of places based on what I'm doing and the accuracy of the machine.

Reply to
Pete C.

Y'see, when Kev is laying out his metalwork with the tape measure...

-- Happiness is not a station you arrive at, but a manner of traveling. -- Margaret Lee Runbeck

Reply to
Larry Jaques

That's better than showing you the Italian cubit gesture.

Reply to
Jim Wilkins

Well, being here still, for now I convert all metric dimensions to inch. Toward my eventual relocation, I'm replacing as many of my micrometers with digital for the inch/mm capability. And looking for such items as metric scales for my Starrett combination square, etc etc etc. I have a full set of inch 5C collets, and metric in full mm increments. I'll be bringing over as much inch materials as I can justify. But am sorta dreading the unavoidable fact that I'm going to be dealing with two systems of measurement for a long time to come.

I am just sorta getting a handle on metric threads, a lot of what I do for one customer is metric. But in terms of linear dimensions, I think in inches and generally still have to look at a conversion chart. If nothing else, just to make sure my general idea of a linear metric dimension is really what I think it is.

Jon

Reply to
Jon Anderson

Only with partial success, at least in the automotive world. My Escort is a mix of inch and metric, and there's a gray area where I am not sure which I'm going to encounter.

Something I found humorous in Australia... First thing I did at a large store (Big W), I checked out the hardware section. I was rather amused to find what I knew to be a 1/4-20 bolt approx 1" long as "1/4 x 30mm".

I stopped by an engineering supply company (more or less the equivalent of MSC) in Wagga Wagga, and was surprised to find a decent selection of nice quality inch taps in stock. Talking to one of the salesmen, they stock a decent selection of inch taps, as well as inch hardware, and what they don't have in stock can be ordered. So even in a supposedly metric country, Imperial hardware survives.

Jon

Reply to
Jon Anderson

I remember that 10mm is very close to four inches, and go from there.

Reply to
Tim Wescott

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