# Metric conversion? Oh No!



## DesertRatTom (Jul 3, 2012)

Every time I try to work with metric, I find myself stuck at some point. Well, having grown up with the imperial system, it always surprises me how difficult the Metric system seems to be to use her in the U.S.A. Now, I've stumbled upon and article that pinpoints why it is such a hassle to me, to use metric. Read on and comment if you will. (From Wikipedia)


_One common complaint about the metric system is that it doesn't provide a natural way to divide things into thirds; even dividing things into quarters requires one to go down two levels, instead of just one, in the system of units, since 0.25 is the decimal that represents 1/4.

The metric system did not divide the day into 100,000 parts; instead, the hour, minute, and second were retained to allow the day to be divided neatly into quarters and thirds.

In response to an instance of the occasionally-heard suggestion that the metric system should have been built on base 12 instead of base 10, it occurred to me that the precedent of an everyday unit, the day, standing in such a relationship to the metric unit, the second, that the day can be exactly divided into 27 parts, each of which consists of an even number of seconds (3200 seconds, or 53 minutes and 20 seconds), one could, for example, use as everyday units a metric pound of 453.6 grams (instead of approximately 453.69 grams) and a metric inch of 2.52 centimeters (instead of 2.54 centimeters).

453.6 grams divides evenly into 81 units of 5.6 grams, and also into 7 units of 64.8 grams - and, for that matter, into 8 units of 56.7 grams. 2.52 centimeters divides evenly into 9 units of 0.28 centimeters, and also into 7 units of 0.36 centimeters - and, for that matter, into 4 units of 0.63 centimeters.

However, I can't really expect that this very wild idea of using this metric pound and metric inch as everyday units, and measuring things out in these pounds and inches, so that they can be evenly divided into thirds, ninths, and sevenths if one uses the regular metric scale, would catch on._

Back to me... There, now I understand why thinking Imperial clashes with measuring metric. 

Water and oil. Matches and gasoline.


----------



## sunnybob (Apr 3, 2015)

That whole article is based on wrong info. check out the link below.

having spent the first 30 years of my life with imperial, and then another 30 in a country that had both (you could buy a half inch garden hose but it had to be 20 metres long, if you wanted a kilo bag of sugar you drove a mile to buy it, etc. etc.) and finally 8 years now in a solely metric country, I can tell you why you have trouble with metric. 

Its not your first language. Just like being bi lingual, you can be fluent in languages, but you will always think in your first one.

I am comfortable now with metric, I dont even have an imperial measure any more, but if I need to describe something to someone, my brain will always come up with 2 foot long, never 60cm or 600mm. Those number require thought.

Why is a minute divided into 60 seconds, an hour into 60 minutes, yet there are only 24 hours in a day? - Scientific American


----------



## cocobolo1 (Dec 31, 2015)

Why should we always have to think in 1/4's, 8ths, 16ths, 32nds, 64ths, 128ths, 256ths. 512ths etc. What's wrong with 10ths?

You and I have been raised imperially, not metrically. But the metric system is extremely easy once you use it for awhile. 

What you have to do is to forget imperial when you are working with metric. It's really quite straight forward.

One day, the U.S will go the way of the rest of the world...metric.


----------



## Stick486 (Jan 4, 2013)

plans call for Imperial use Imperial measuring devices...
do it the same way for metric and don't about conversions...


----------



## cocobolo1 (Dec 31, 2015)

stick486 said:


> plans call for imperial use imperial measuring devices...
> Do it the same way for metric and don't about conversions...


prezackly!


----------



## vindaloo (May 30, 2009)

Glad Stick said that. I use both and I was bought up mainly with metric. My dad used imperial, he was an apprentice engineer draughtsman in the late 50's, early 60's and use imperial then and in his woodworking. So I saw that side and then at school metric had just come in so I learned that. Now I use whatever is suitable for the situation.

I get the problem dividing 10 by 3 in engineering, but in carpentry is there really a problem? After all a third of a mm is a sneeze out.


----------



## Hutzul (Oct 4, 2012)

I trained as a mechanical engineer in the early 1970's, where at college we were told to forget imperial and we were taught in metric. However back at work as a toolmaker we worked in imperial, so like vindaloo ' Now I use whatever is suitable for the situation'.
I prefer to use metric, especially when the calculator is in play.


----------



## neville9999 (Jul 22, 2010)

DesertRatTom said:


> Every time I try to work with metric, I find myself stuck at some point. Well, having grown up with the imperial system, it always surprises me how difficult the Metric system seems to be to use her in the U.S.A. Now, I've stumbled upon and article that pinpoints why it is such a hassle to me, to use metric. Read on and comment if you will. (From Wikipedia)
> 
> 
> _One common complaint about the metric system is that it doesn't provide a natural way to divide things into thirds; even dividing things into quarters requires one to go down two levels, instead of just one, in the system of units, since 0.25 is the decimal that represents 1/4.
> ...


You are overly complicating it as Metric is as easy as it gets so just forget all that can't divide pounds with rubles. Oh and when you get a minute can you tell me what a 1/3 of 11/64ths is? N


----------



## OPG3 (Jan 9, 2011)

Metric is base ten because men (and women) have 10 fingers - it is as simple as that.
I use both systems and quickly recognize the comparative stupidity of the imperial system.
An inch is 1/12th of a foot and neither one of those has anything whatsoever to do with a pound or an ounce.
And still neither of those has anything whatsoever to do with quarts or gallons. Imperial is a goofy system and after a long career in engineering, I can honestly say that one spends quite a bit of time making volumetric and weight calculations.

The basic metric unit of measure is the meter. 1/100 is a centimeter and 1/1000 of the meter is a millimeter.
Using water (the standard in chemistry & physics), one cubic centimeter weighs one gram. Just as simple as that proves the stupidity of imperial units of measure. Therefore, one liter of water, weighs one kilogram.

Now, try that with inches and feet vs. pounds or ounces vs. quarts and gallons and those of you who are metric naysayers have just proven that you have a deep lack of understanding of this inherent simplicity.

My products are sold globally and fortunately most of the planet uses metric. Rather than sit-around and gripe about it, I chose to embrace the system and see it for what it really is...SMART!

Otis Guillebeau from Auburn, Georgia


----------



## Gaffboat (Mar 11, 2012)

Although I do most everything with imperial measurements, I often resort to metric for my projects when I need precision that's easy to measure and to add and subtract.


----------



## Shop guy (Nov 22, 2012)

I follow along with Stick. I use both systems and have no problems as long as I don't try to mix them.


----------



## BOjr (Dec 1, 2012)

For almost 40 years I worked and produced metric working drawings for structures. We were always converting the metric to imperial and visa versa. Many of the products used in the structures were made in the USA and therefore the conversions had to be made to insure that they would fit. If you are not working in really large dimensions there are really only two things you have to remember:

1'- 0" = 30 cm

1" = 2.54 cm


----------



## DesertRatTom (Jul 3, 2012)

I have a metric / imperial tape measure and a couple of combination rules, so I can use metric if needed. You all make good points. I was not necessarily advocating for Imperial. I can picture and estimate a yard, but not a meter, an inch, but not automatically 2.5 cm. It is not my first language pretty much pegs it.


----------



## Stick486 (Jan 4, 2013)

if the plans are done in Imperial engineer use engineer scales...

you need thirds (precisely) rotate your measuring device across the face/edge of the material till a unit of measure (whole number) that is easily dividable by 3 intersects the opposite edge..

ie...
Imperial...
0 and 3, 6, 9 or 12'' and so on and what ever fits best... 
for narrow pieces - 0 and 1½'', 0 and ¾''... etc...
metric...
same thing...
engineer..
same thing..
mark your material at the desired interval...
ie.. 0-12 would be marked at the 4 and 8'' increments.. 0-3 will be at the 1 and 2'' intervals...
if you need those measures more than once save them w/ a set of dividers, a compass or a marking gauge and transfer them as needed...

so much over thinking isn't good for the brain..
stop w/ the conversions and keep the math KISS/MISS...
avoid errors...

*NOTE:*
if you use a tape measure w/ a hook and you rotate the tape ''down'' mark from the top of the tape...
if you rotate up use the bottom of the tape to mark from...
this also works for any segment count you want... even or odd numbered...


----------



## Stick486 (Jan 4, 2013)

BOjr said:


> For almost 40 years I worked and produced metric working drawings for structures. We were always converting the metric to imperial and visa versa. Many of the products used in the structures were made in the USA and therefore the conversions had to be made to insure that they would fit. If you are not working in really large dimensions there are really only two things you have to remember:
> 
> 1'- 0" = 30 cm
> 
> 1" = 2.54 cm


isn't 1 foot 30.48CM???


----------



## DaninVan (Jan 1, 2012)

*Touche'*



Stick486 said:


> isn't 1 foot 30.48CM???


And that, Folks, is why doing conversions is a beartrap.


----------



## cocobolo1 (Dec 31, 2015)

Stick486 said:


> isn't 1 foot 30.48CM???


Yes, it is and we usually call it 305 mm.


----------



## Cherryville Chuck (Sep 28, 2010)

A lot of the issues can be solved by using the right tool for the job. As has been said, "Don't try to convert and don't mix the two".

A millimeter is slightly less than 1/25th of an inch which is about all I can accurately see anymore. Half that is starting to get close to 64ths which I have to use a magnifying glass to read accurately. I like to use 0.5 mm mechanical pencils in my shop so that is a line 1/2 mm in width. If you estimate the difference between millimeters you'll be plenty close enough and still limited by the width of the pencil line and our ability to estimate where on that line we should be working to.


----------



## Stick486 (Jan 4, 2013)

cocobolo1 said:


> Yes, it is and we usually call it 305 mm.


so after extended measures the collective will make things go askew...
and here, 1/500th of an inch, is major issue...
go figure...


----------



## Garyk (Dec 29, 2011)

Google "Bobsrule". Saw an article on this eons ago where an engineer combined metric & imperial on a rule to eliminate confusion(or make it worse) and simplify things. Don't have one so I can't say one way or the other but it's interesting trivia. The basic idea is he divided an inch into 24 parts on the rule, so 1 "Bob" equals 1" divided into 24 segments (less than 1/16 -- more than 1/32).

Bobsrule & Other Tools :: Whitechapel Ltd. 

_*Don't ask me where you can get plans measured in Bob's cause I don't know.*_


----------



## Cherryville Chuck (Sep 28, 2010)

I`m afraid I can`t agree with Bob`s rationale and he should have read where the 360* came from that made up the circle and the 60 minutes that make up an hour. As SunnyBob pointed out we have the ancient Sumerians to thank for that because they used a math system with base 60. The earliest known reference of math to the base 10 was about 500 B.C. in Sanscrit writings, up to several thousand years after the Sumerians had already divided the circle, and it took about 2300 more years before we finally designed a measuring system around base 10.


----------



## cocobolo1 (Dec 31, 2015)

Stick486 said:


> so after extended measures the collective will make things go askew...
> and here, 1/500th of an inch, is major issue...
> go figure...


Just wait until tomorrow...tolerances here will be down to .001".

Next week...???


----------



## Stick486 (Jan 4, 2013)

cocobolo1 said:


> Just wait until tomorrow...tolerances here will be down to .001".
> *
> Next week...??*?


depends on if Nick gets his trimmer dialed in or not...


----------



## JFPNCM (Dec 13, 2009)

Reminds me of the first Bureau of Reclamation project I worked on where the guys in the orange hats had rulers marked off in 100ths of a foot. I still have mine in a drawer some where.


----------



## jw2170 (Jan 24, 2008)

I hope Harry does not see this post......LOL...


----------



## DesertRatTom (Jul 3, 2012)

Garyk said:


> Google "Bobsrule". Saw an article on this eons ago where an engineer combined metric & imperial on a rule to eliminate confusion(or make it worse) and simplify things. Don't have one so I can't say one way or the other but it's interesting trivia. The basic idea is he divided an inch into 24 parts on the rule, so 1 "Bob" equals 1" divided into 24 segments (less than 1/16 -- more than 1/32).
> 
> Bobsrule & Other Tools :: Whitechapel Ltd.
> 
> _*Don't ask me where you can get plans measured in Bob's cause I don't know.*_


I have a retractable tape measure marked in both, and a couple of straight metal rulers marked in both. I can work in either, I just can't visualize odd metric lengths.


----------



## CAD-Man (Apr 28, 2013)

Try Ham (amateur) radio. Bands are measured in meters which convert to Hertz which is cycles per second, Then there are formulas to convert frequency in hertz to 1/4 1/2 or 5/8 wave length into inches or feet. So you end up with Metric, Imperial and Time all intermixed.

CAD-Man


----------



## JIMMIEM (Apr 4, 2010)

Does the military use metric? I've heard distances referred to in 'Klics' (kilometers?). Is this real or Hollywood? How is this taught to military folks?


----------



## vindaloo (May 30, 2009)

jw2170 said:


> I hope Harry does not see this post......LOL...


Yeah, seems like Déjà vu to me.


----------



## sunnybob (Apr 3, 2015)

I cant be bothered to do the research, and we are wandering away from metric, but from my school days memory, minutes and seconds have nothing to do with any ancient civilisations.
When clocks were being invented, the mechanisms required cogs to accurately repeat the hands movements. the size of the cogs determined how many "ticks" there were in a day, and those "tocks" were reduced to easily read numbers.

And I should know as I grew up only 5 miles from Greenwich, which is where it all started.

Bob, (GMT+2)


----------



## Stick486 (Jan 4, 2013)

JIMMIEM said:


> Does the military use metric? I've heard distances referred to in 'Klics' (kilometers?). Is this real or Hollywood? How is this taught to military folks?


they do...
it's real...
range is in meters...


----------



## Cherryville Chuck (Sep 28, 2010)

NASA made the announcement several years ago that all calculations henceforth would be in metric. I think most of them already were. Yes, we refer to them as klics.


----------



## Frankj3 (Oct 6, 2014)

This is one of the few threads on this forum that I have read from the first post to the last. And I don't really care for that much reading.....I'm more of a video watching guy.

I am not an engineer.....not a physicist.....not a psychologist.....nor any kind of expert. I am a college degreed machinist.....woopty-doo! I am also a person who grew up with the Imperial measurement system. Yes, I was taught metric in the military and in college. But here, in Texas, in the real world, in the machine shop where I have worked for over 36 years, we still use Imperial. Yep, we get prints from all over the world to manufacture parts. These prints tend to have both metric and Imperial measurements shown.

Oh my! Guess what? When we finish manufacturing and inspecting our parts with the Imperial system of measure, we ship them to our customers.....all over the world.....and they work for the form, fit and function intended.....even when measured using the Metric system.

I really don't give a rats behind which is "superior or better".......they both work in the world. It's all about what each person is comfortable using. So it's Imperial for me.


----------



## DaninVan (Jan 1, 2012)

We gotta stop meeting like this...


----------



## Stick486 (Jan 4, 2013)

DaninVan said:


> We gotta stop meeting like this...


now what are we like...

alpha males..
Focused...
dynamic...
handsome..
intelligent..
savvy...
virile...
strong...
courageous..
have purpose...
decisive...
word is bond
healthy...
speak our minds...
not controlled..
decision makers...
role models..
considerate...

so why not meet...


----------



## sunnybob (Apr 3, 2015)

Cherryville Chuck said:


> NASA made the announcement several years ago that all calculations henceforth would be in metric. I think most of them already were. Yes, we refer to them as klics.


ever since 1999,

NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.

A navigation team at the Jet Propulsion Laboratory used the metric system of millimeters and meters in its calculations, while Lockheed Martin Astronautics in Denver, which designed and built the spacecraft, provided crucial acceleration data in the English system of inches, feet and pounds.

As a result, JPL engineers mistook acceleration readings measured in English units of pound-seconds for a metric measure of force called newton-seconds.

In a sense, the spacecraft was lost in translation.

"That is so dumb," said John Logsdon, director of George Washington University's space policy institute. "There seems to have emerged over the past couple of years a systematic problem in the space community of insufficient attention to detail."


----------



## DaninVan (Jan 1, 2012)

Stick486 said:


> now what are we like...
> 
> alpha males..
> Focused...
> ...


Sounds right. But folks will get the wrong idea... :surprise:


----------



## Stick486 (Jan 4, 2013)

DaninVan said:


> Sounds right. But folks will get the wrong idea... :surprise:


not a chance...


----------



## Arcola60 (Jul 4, 2009)

Both measurement methods work. It comes down to what system we are most comfortable with. I personally use the Imperial system, because I was raised with it. It is second nature to me. I can convert very easily. Being a machinist, I use decimal over fractions, mainly because of tolerances. I am still converting within the system. Also because most of my measuring tools are not metric. I totally understand the metric system and its benefits, and I do use it. Each day I get better at the conversions in my head. Thank God that I have a calculator! I am glad to see that this post was considerate to our choices.

We can discuss which one is better than the other, or we can just go out and create something that reflects and showcases our wonderful talents. Don't forget to post the pictures. You know how much we like pictures.


Ellery Becnel


----------



## Cherryville Chuck (Sep 28, 2010)

sunnybob said:


> ever since 1999,
> 
> NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.
> 
> ...


When I was learning physics at the University of Alabama in the late 60s/early 70s we were taught solely in metric. Imperial measures were never even mentioned. However, the engineers I knew were being taught Imperial measures such as foot-pounds, pounds per square inch, and pound-seconds. So it is very possible that the guys who were building the equipment were using Imperial and the ones calculating trajectories and orbits were using metric even way back then.


----------



## neville9999 (Jul 22, 2010)

sunnybob said:


> ever since 1999,
> 
> NASA lost its $125-million Mars Climate Orbiter because spacecraft engineers failed to convert from English to metric measurements when exchanging vital data before the craft was launched, space agency officials said Thursday.
> 
> ...


On one of the first Airbus flights then ground staff failed to correctly load the fuel, it seems that they did not get the conversion from pounds of fuel to kilos of fuel worked out so the aircraft ran out long before it should have and it required the pilot to glide a wide body aircraft in with very little control into a landing, something he did. The thing is that Imperial micro fractions really refer to engineers who make items with such precision that they have to measure them with micrometers and dial devices and none of this is required to work with wood, no one can possibly measure or mark microns or thousandths of an inch with a pencil, working with metric and wood does not require conversion or division by thirds, no one who uses metric uses any size smaller than 1mm. N


----------



## Nobodi (Oct 22, 2015)

Neville I would guess box joints or dovetails would be very loose or very tight if one only were working with 1mm as the smallest incroment.


----------



## cocobolo1 (Dec 31, 2015)

Nobodi said:


> Neville I would guess box joints or dovetails would be very loose or very tight if one only were working with 1mm as the smallest incroment.


I think what Neville means is that we wouldn't normally measure much closer than 1mm. But fitting something is another matter entirely. 

Certainly with dovetails we strive for perfection, which is definitely much less than 1 mm! :smile:


----------



## Cherryville Chuck (Sep 28, 2010)

cocobolo1 said:


> I think what Neville means is that we wouldn't normally measure much closer than 1mm. But fitting something is another matter entirely.
> 
> Certainly with dovetails we strive for perfection, which is definitely much less than 1 mm! :smile:


I can't normally measure the difference between a poor fitting dovetail and a well fitted dovetail in Imperial either, at least not without a pretty good magnifying glass. That's one of those things you fit together and if it doesn't fit right you make adjustments to the jig.


----------



## neville9999 (Jul 22, 2010)

Nobodi said:


> Neville I would guess box joints or dovetails would be very loose or very tight if one only were working with 1mm as the smallest incroment (spelt 'increment') .


This type of comment just confuses the issue, any persons making dovetails makes them so that the tails fit the sockets and that's regardless of how they were measured, if they are 1 inch across the top of the tails or 24.5mm across the top of the tails, that's the same size by the way but were I setting them out with metric then I would not be using a fraction of a mm but a even full number so I would use 25mm and not 25.4, so then whatever size the tail is then the socket needs to also be cut to suit the selected tail size and angle. whatever increment is used then its a poor dovetail-er if he can't get them the same. The fact is that using metric is easier than this conversation suggests it is and whatever method is used then accuracy for the cuts for the tails and the sockets have nothing to do with the unit of measurement chosen to set them out. I am very confident that were I to set out dovetails where I used a 18th of a cubit as my selected tail size then I would get the cuts correct and the sockets would suit the tails. N

PS for the anally retentive, an 18th of a cubit is an inch


----------



## sunnybob (Apr 3, 2015)

When I was a kid I also learnt roods, poles, perches and chains.
Did you know a cricket pitch is 1 chain between wickets?

No wonder my shrink says I'm confused.


----------



## Bodger96 (Mar 18, 2014)

For me Imperial is the first language of measuring that I learned and that is what I think in. But I love the metric system because as a construction carpenter I only need metres and millimetres. When I require equal spaces (Dovetails) I don't do the math but use geometry(a la Stick). This is because if I had a space of 207 mm to divide into 13 equal spaces, and the spaces required mathematically came out to 15.923 mm Approximately, how do I measure that? I really don't need to know the actual number, I just need equal spaces. You can be super accurate in either system. I happen to be from Canada and we have one foot in both systems. It is when we try to convert that we make errors.

Regards Bob


----------



## neville9999 (Jul 22, 2010)

sunnybob said:


> When I was a kid I also learnt roods, poles, perches and chains.
> Did you know a cricket pitch is 1 chain between wickets?
> 
> No wonder my shrink says I'm confused.



Thanks Bob, for all my years of watching Cricket played I did not know that the length of the pitch was 1 Chain. I always thought that they chose that size because if it were any longer then the bowler could not hit the batsman in the head. N


----------



## Cherryville Chuck (Sep 28, 2010)

neville9999 said:


> I always thought that they chose that size because if it were any longer then the bowler could not hit the batsman in the head. N


I thought that was only a strategy in North American baseball that pitchers used against batters that persistently crowded the plate.


----------



## cocobolo1 (Dec 31, 2015)

neville9999 said:


> PS for the anally retentive, an 18th of a cubit is an inch


Good thing you reminded me.

When me and Noah built the Ark, we used Cubits. I know that Noah gets all the credit for that little boat...but it's only because he had better P.R. than I did. >


----------



## Cherryville Chuck (Sep 28, 2010)

The cubit was probably around for a long time but I have no idea what it was based on. The inch was based on the distance between 2 knuckles on the king's thumb or the last knuckle and the tip and the foot was the length of his foot. Obviously the standard kept changing as one king died and another started his/her reign. That was what the French Royal Academy sought to change when they devised the metric system in 1792. It was meant to be reproducible no matter where you are or when you are. The only standard in metric that has changed in the 200 plus years it has been in existence is the length. It was originally 1/10,000,000 the distance from the equator to the north pole but they eventually realized that that distance is not a constant.


----------



## sunnybob (Apr 3, 2015)

neville9999 said:


> Thanks Bob, for all my years of watching Cricket played I did not know that the length of the pitch was 1 Chain. I always thought that they chose that size because if it were any longer then the bowler could not hit the batsman in the head. N


And for people who think imperial is base twelve...
1 chain (22 yards) x 10 (thats TEN, not twelve) equals a furlong, and 8 furlongs equal a mile.

Sort that out among the twelve of you.


----------



## DaninVan (Jan 1, 2012)

*Makes sense to me!*



sunnybob said:


> And for people who think imperial is base twelve...
> 1 chain (22 yards) x 10 (thats TEN, not twelve) equals a furlong, and 8 furlongs equal a mile.
> 
> Sort that out among the twelve of you.


So, basically a mile (1,760yds.)  =220yds.
8

And a 1/10th of a furlong is a chain.


----------



## sunnybob (Apr 3, 2015)

By george he's got it!

Furlongs are only ever used now in horse racing that I know of, chains have been completely forgotten (I doubt even many cricketers know why their wickets are that distance), and I'm not even going to bother looking up poles and perches.

should we now move on to tuns, barrels, and firkins?

Ask me why i love metric, go on.


----------



## DaninVan (Jan 1, 2012)

Nope; not gonna happen...


----------



## Cherryville Chuck (Sep 28, 2010)

Never mind the obscure measures Bob. The standard ones are strange enough.

12 inches to the foot
3 feet to the yard
1760 yds per mile
5280 feet per mile
2000 lbs per ton
16 ozs per lb
7000 grains per lb
4 quarts per gallon
2 pints per quart
32 oz per quart
2 cups per pint 
8 oz per cup
2 tablespoons per oz
8 gallons per bushel or also equal to 4 pecks

Yup! Makes perfect sense. :no:


----------



## AndyL (Jun 3, 2011)

sunnybob said:


> By george he's got it!
> 
> Furlongs are only ever used now in horse racing that I know of, chains have been completely forgotten (I doubt even many cricketers know why their wickets are that distance), and I'm not even going to bother looking up poles and perches.


Also used in land measurement - an acre is 1 chain by 1 furlong.


----------



## sunnybob (Apr 3, 2015)

Andy, how many estate agents do you see carrying a 22 yard chain in their back pockets? (lol) GPS rules ok?

Charles, you do realise that several of your measurements there are USA and NOT imperial?

We have 16 ounces (oz) per pound (lb), 14 pounds per stone (strangely, no real abbreviation for stone), 8 stone per hundredweight (cwt) 20 hundredweight per ton (giving 2240 lbs per ton), and 20 fluid ounces per pint, 40 per quart, 160 per gallon.

Metric has litres and kilos. 

Easy peasy lemon squeezy.

hey, I finally accept that I WAS taught something at school, even if it was only enough to rake part in a stupid thread.


----------



## Cherryville Chuck (Sep 28, 2010)

Yes I gave the US Imperial measure. The Canadian quart and gallon were the same as British. The inches were all the same though and that's because Britain had the US making Enfield parts around 1940 as British factories could not keep up. The British and US inches were slightly different such that some of the parts would not fit if tolerances were too far the wrong way. They got together and agreed that the unified new inch measure would be equal to 25.4 mm. So since about 1940 the inch has been metric based.


----------



## JFPNCM (Dec 13, 2009)

Many years ago a friend who was a math whiz and equally talented with his slide rule (that should date it) worked out a speed/distance problem on a physics quiz in furlongs per fortnight. He got an A on the exam along with a very nasty note 'Don't ever do that again".


----------



## Cherryville Chuck (Sep 28, 2010)

That's funny Jon. The teacher probably had to go read some reference books to be able to grade it.


----------



## JFPNCM (Dec 13, 2009)

Cherryville Chuck said:


> That's funny Jon. The teacher probably had to go read some reference books to be able to grade it.


No doubt. All in good fun if you're not the Prof.


----------



## papasombre (Sep 22, 2011)

Well... here we are, agaaaiinnn!!!


----------



## Knothead47 (Feb 10, 2010)

You can convert just about anything into something else. Clear as mud, huh? I use it for converting length, volumes, weight, etc. all the time.
http://www.onlineconversion.com


----------



## Herb Stoops (Aug 28, 2012)

Knothead47 said:


> You can convert just about anything into something else. Clear as mud, huh? I use it for converting length, volumes, weight, etc. all the time.
> Online Conversion - Convert just about anything to anything else


I make up my own. Mark and cut, remark and cut, mark and a smidgen more or less and cut. Throw that piece away too short, get a new piece mark and add a little bit and cut...........:grin::grin::grin::grin:

Herb


----------



## DaninVan (Jan 1, 2012)

Herb's system is Universal.


----------



## Herb Stoops (Aug 28, 2012)

DaninVan said:


> Herb's system is Universal.


Funy how pencil marks grow,a dozen pencil marks equals 3/4".:grin::grin:

Herb


----------



## JFPNCM (Dec 13, 2009)

Herb Stoops said:


> Funy how pencil marks grow,a dozen pencil marks equals 3/4".:grin::grin:
> 
> Herb


Only if you use carpenter pencils which are 1/16" wide at the tip. :wacko:


----------



## neville9999 (Jul 22, 2010)

Cherryville Chuck said:


> The cubit was probably around for a long time but I have no idea what it was based on. The inch was based on the distance between 2 knuckles on the king's thumb or the last knuckle and the tip and the foot was the length of his foot. Obviously the standard kept changing as one king died and another started his/her reign. That was what the French Royal Academy sought to change when they devised the metric system in 1792. It was meant to be reproducible no matter where you are or when you are. The only standard in metric that has changed in the 200 plus years it has been in existence is the length. It was originally 1/10,000,000 the distance from the equator to the north pole but they eventually realized that that distance is not a constant.


There is a Biblical reference that says a cubit is 22inches and that a cubit is the length from your elbow to your thumb but that would vary from person to person, Dr Google says its 18inches, the only point I tried to make is that it does not matter how you calculate a measurement what is important is that you use that system accurately and that you can then cut on your line, if you cannot cut on your line then it does not matter what system you did use as the joint will be loose, You could set out your dovetails in fractions of a mile so 1/63360th of a mile is an inch, whatever measurement is used if you can't cut on the line then the join will be loose. N


----------



## Herb Stoops (Aug 28, 2012)

neville9999 said:


> There is a Biblical reference that says a cubit is 22inches and that a cubit is the length from your elbow to your thumb but that would vary from person to person, Dr Google says its 18inches, the only point I tried to make is that it does not matter how you calculate a measurement what is important is that you use that system accurately and that you can then cut on your line, if you cannot cut on your line then it does not matter what system you did use as the joint will be loose, You could set out your dovetails in fractions of a mile so 1/63360th of a mile is an inch, whatever measurement is used if you can't cut on the line then the join will be loose. N


I agree, but the line keeps disappearing and then coming back down the line. So I have to average then compensate, then everything becomes equal and fits together. Soaking in the bathtub helps tighten the joints too. 
Herb


----------



## DaninVan (Jan 1, 2012)

"Soaking in the bathtub helps tighten the joints too.'
-Herb

I prefer a hot shower myself.


----------



## DesertRatTom (Jul 3, 2012)

On pencil marks. For fine cuts, can't beat a marking knife. For pencils, I keep a small sharpener and buy orange, Home Depot pencils with dark and skinny lead. Point is very sharp and maybe 1/64 th at most at the tip. Resharpen often. Then curse when its too short!!!#@$!. 

But now, for some pieces, I can use the Lion trimmer to shave to fit, easier than a block plane.


----------



## Cherryville Chuck (Sep 28, 2010)

My shop pencils are .5mm mechanical, never need sharpening, never get bigger than .5mm. That is about 1/51" Tom so same ballpark. I also use a marking knife or utility knife to make extremely accurate marks. I think a knife line is about 1/250" according to something I read once, probably in Lee Valley's catalog.


----------



## Herb Stoops (Aug 28, 2012)

Cherryville Chuck said:


> My shop pencils are .5mm mechanical, never need sharpening, never get bigger than .5mm. That is about 1/51" Tom so same ballpark. I also use a marking knife or utility knife to make extremely accurate marks. I think a knife line is about 1/250" according to something I read once, probably in Lee Valley's catalog.


I have a hard time seeing a knife line. The mechanical pencil sounds good might try that, in the past tho I kept breaking the lead. I have been using the LV 2B pencils ,but the are sort of soft and get dull fast. I too have a pencil sharpener handy, but the pencils get short pretty fast. I like the LV pencils for the ability to erase easily any extra pencil marks. 

Herb


----------



## Cherryville Chuck (Sep 28, 2010)

I tried the LV pencils but had the same result. Once I used the mechanical pencils for a day or two I was sold on them. Some prefer the .7mm size instead because they are tougher but I don't have a problem breaking the .5 ones anymore unless I'm trying to mark something with a really rough texture. If I'm marking something with a rough texture it isn't for a fine fit or finish so the regular carpenter's pencil is ok for that. For carpenter's pencils I normally only use the retractable one that LV sells for around $4. I admittedly don't pack it around in an apron much but I find it far superior to the wooden ones.


----------



## tomp913 (Mar 7, 2014)

DesertRatTom said:


> On pencil marks. For fine cuts, can't beat a marking knife. For pencils, I keep a small sharpener and buy orange, Home Depot pencils with dark and skinny lead. Point is very sharp and maybe 1/64 th at most at the tip. Resharpen often. Then curse when its too short!!!#@$!.
> 
> But now, for some pieces, I can use the Lion trimmer to shave to fit, easier than a block plane.


 Instant cure for short pencils, you can use them down to the metal tube that holds the eraser.
Pencil Lengthener by Creative Mark - JerrysArtarama.com
http://www.amazon.com/Derwent-Pencil-Extender-Pencils-2300124/dp/B002U0OX4C

I have both types, been using them since my apprentice days back in Scotland. I've got a couple of the fancy aluminum ones that must be made for a slightly larger pencil than the yellow ones that you can find everywhere. If you can find them locally, see if they'll let you try the fit on the pencils that you usually use.

I actually prefer the ones with the wooden end as they're the same diameter as a pencil, some of the aluminum ones feel clumsy at first.


----------



## woodknots (Mar 7, 2012)

Herb:

"I have a hard time seeing a knife line"

Use a marking knife then go over the knife line with a pencil - best of both worlds.


----------



## Stick486 (Jan 4, 2013)

vchiarelli said:


> Herb:
> 
> "I have a hard time seeing a knife line"
> 
> Use a marking knife then go over the knife line with a pencil - best of both worlds.


mechanical pencils...
4 sizes (0.3. 0.5, 0.7, 0.9) to pick from...
cheap too... around a buck 25-50 ea..
10 pack... 90-95 cents...
lasts for long time...
Pentel
lots of colors to pick from to help out w/ visibility...
Pentel


----------

