New to metric but not to Festool - need advice for measuring

[guybo]

A smart way to get metric naturally

1million mircophone=1 megaphone 52=1 decacards 1/2 lav=1 demijohn and 1 millionth of a fish=1micro fish [big grin]

 

[Crazyraceguy]

Exactly Crazyraceguy, I remember this was a part of transition to metric (48x98mm)
Then I thought, why on earth not 50x100? so much easier - then someone said it’s about adding with other dimensions and drying of lumber.. slippery slope - I think that’s why 2x4 stayed.. easy to remember and speak out - and visualise.

Should I advise, try round up (or down) to closest fully centimetre - leave the metric fractions out when thinking metric.

A systainer is something you all are familiar with: It’s built to fit a 30x40cm space with slight wiggle room [wink] - Euro packing size..
Visualising in whole, round numbers are easier. If you must have it in Millimeters - add a “0” and you have it.
Or, subtract a “0” from Millimeters, and you have centimetres.

I am slowly getting it, which is generally better for me. That means it can stick and become automatic. It really would help if everybody in the shop did it. When everybody is on the same page, converting back and forth doesn't need to happen. Then a typical 24" or 30" cabinet would "look" like 610mm or 760mm. and probably get simplified even more to 600 and 750.

 

[Ron B]

I remember about 1980 when Shell Oil gas stations tried to sell gas by the liters in the U.S.  Since every gas station always sells gas at XXX and 9/10 of a cent it was considered just another marketing ploy and went over like a lead balloon. 

Although I agree that metric is easier to work with, I think imperial works better for land measurements, especially for the early surveyors trying to survey land without getting scalped by the people whose land they were surveying.  It is easier to take a square mile and divide into half, then half again (fourths) instead of tenths and tenths again.  So a square mile (section or 640 acres) becomes a quarter section (160 acres), then that is again divided into fourths to get 40 acres or 1320 feet by 1320 feet. So 1320 times 1320 divided by 40 equals 43,560 square feet per acre-see how simple that is?  Everything was measured by rods at 16 1/2 feet (5280 feet per mile/16.5 feet per rod equals 320 rods per mile) or chains at 66 feet. The surveying chain must be an attempt to be metric since it has 100 links.  So that makes a link 7.92 inches.  I have read 200 year old surveys of farm property where it was surveyed to within 1/2 link.  Today, people cannot even read a tape measure. 

I have my grandfather's math book from about 1905.  One of the problems gave the dimensions of a cabin with a certain overhang, and the pitch of the roof.  It then said how many square feet a bundle of shingles would cover, and asked how many bundles you needed to order.  Remember this is one room school houses where you graduated at eighth grade.  How do you think kids would do today with that problem?

 

[Michael Kellough]

80 centimeters or 300 centimeters would just sound funny.

Or abbreviated...800 mils vs 80 cents. Cents sounds funny to me. Does anyone abbreviate centimeters to cents?

Once upon a time I was installing some paintings in Soho for the artist Cy Twombly. He grew up in South Carolina and although he’d been living in Rome for a couple decades he still had a southern accent. I told him how many inches one  painting was from the next and he wrinkled his face and said “Give it to me in sin-tim-iters”.

 

[Coen]

Although I agree that metric is easier to work with, I think imperial works better for land measurements, especially for the early surveyors trying to survey land without getting scalped by the people whose land they were surveying.  It is easier to take a square mile and divide into half, then half again (fourths) instead of tenths and tenths again.  So a square mile (section or 640 acres) becomes a quarter section (160 acres), then that is again divided into fourths to get 40 acres or 1320 feet by 1320 feet. So 1320 times 1320 divided by 40 equals 43,560 square feet per acre-see how simple that is?

Haha "for x I think this dumbass system is easier .... [giant explanation following]".

No it's junk. A square km = 1.000.000 square meters. 10.000 square meters = 1 hectare.

 

[Michael Kellough]

See, that's just funny  [blink] Everybody "knows" what a 2 x 4 is, yet there is literally no such thing. LOL They are 1 1/2" x 3 1/2" here. That was standardized decades ago when most of them were actually 1 5/8" x 3 5/8" and it made for odd dimensions during construction. A residential interior wall would be covered with 1/2" drywall (gypsum board) resulting in a total thickness of  4 1/2". Getting rid of those 1/8ths seemed to help.

I am always surprised by the simple things that are done in other countries, which are based on American standards. Years ago, when I first heard about "Baltic Birch" plywood and that it was supplied in 60 x 60 sheets, I thought it was odd? Why be different in the first place? but also why in inches? 1500mm? that would be 59"

I just can't get with the folding rule thing. I don't really know why, but they seem crude and clunky. They were commonly used when I was a kid, but not any more.

The 1220 x 2440 thing was just metric conversion from American 4' x 8', but again, why? Is it just that common over there to stick with it as a standard, even though it does not "fit" with the metric measurements?

The studs in my 130 year old house are full 2x4 inches.

Folding rule. Back in my old days my boss got heavily into Sufism. He decided to convert one of his buildings into a Mosque and brought two carpenters over from the Istanbul Archeological Museum and my task was to set up a woodworking shop for them. When it got to the small stuff they wanted metric tools. The best I could find then was big fat Stanley tape measure. They hated it. One of the guys had brought a beat up old folding metric rule so they broke it in two and built some incredible stuff. One of them built the minbar and the other made the mihrab.

Sort of like these.

At one point one of the guys was nailing molding in place and a visitor asked (in shock) why he wasn’t using something like a dowel. The carpenter held up a nail and said “steel dowel”.

 

[Mini Me]

We still struggle in the UK though because our schools teach metric - in centimetres! 

My wife is a qualified fashion and design person and the sewing industry uses centimetres which I find totally frustrating and confusing. If I am working with someone we never use millimetres just saying the actual measurement and there is never any misunderstanding.

 

[Bob D.]

"I just can't get with the folding rule thing."

First tool I pick up when I enter the shop. Been using one since I started my apprenticeship and never stopped.

I find a folding rule easier than a tape in many situations. Not better just easier for me to use since I have been using them for 50 years. I still have the rule I got when I started. It's no good anymore as the joints are worn out but my Father-in-Law gave it to me when I started and he passed only a couple years later so I've hung on to it.

 

[rmwarren]

"I just can't get with the folding rule thing."

First tool I pick up when I enter the shop. Been using one since I started my apprenticeship and never stopped.

I find a folding rule easier than a tape in many situations. Not better just easier for me to use since I have been using them for 50 years. I still have the rule I got when I started. It's no good anymore as the joints are worn out but my Father-in-Law gave it to me when I started and he passed only a couple years later so I've hung on to it.

I'm trying, started keeping one in my apron along with the Hultafors tape, 150mm steel rule and Paolini rule. I still grab the tape for most stuff but when I do use the folding rule it works no problem.

I think it's just muscle memory.

RMW

 

[Crazyraceguy]

A folding rule is just not practical for the size of the things that I build, but even for smaller things, I just can't get past the joints. It just seems to me that those are dead spots. I realize that you could place a pencil mark at a particular even inch/centimeter point, then move the rule to that point and complete the measurement. But why would you want to do that? Not only is it 2 steps, it increases the chances of mathematical errors. The "burning an inch" that has plagued people for years is a similar problem.
This seems to have morphed a bit, but a very interesting study of the differences of how we do things.

 

[Mini Me]

I despise push sticks but someone pointed out to me that with a folded rule in your pocket you always have a push stick to use.

 

[Coen]

Exactly Crazyraceguy, I remember this was a part of transition to metric (48x98mm)
Then I thought, why on earth not 50x100? so much easier - then someone said it’s about adding with other dimensions and drying of lumber.. slippery slope - I think that’s why 2x4 stayed.. easy to remember and speak out - and visualise.

Should I advise, try round up (or down) to closest fully centimetre - leave the metric fractions out when thinking metric.

A systainer is something you all are familiar with: It’s built to fit a 30x40cm space with slight wiggle room [wink] - Euro packing size..
Visualising in whole, round numbers are easier. If you must have it in Millimeters - add a “0” and you have it.
Or, subtract a “0” from Millimeters, and you have centimetres.

I am slowly getting it, which is generally better for me. That means it can stick and become automatic. It really would help if everybody in the shop did it. When everybody is on the same page, converting back and forth doesn't need to happen. Then a typical 24" or 30" cabinet would "look" like 610mm or 760mm. and probably get simplified even more to 600 and 750.

Standard kitchen cabinet is 600mm here. Than you change it out from shelves to drawers to oven, to fridge... without a problem, as all are designed for 600mm. Or take out a mid cabinet and put in a dish washer.

Not sure if you want a 2nd oven in the new kitchen? Put in the outlet, pick a 600 mm cabinet and you always have the option to change.

 

[Bob D.]

I despise push sticks but someone pointed out to me that with a folded rule in your pocket you always have a push stick to use.

LOL, that would be risky and a waste of a good rule to boot. Too much metal in a typical folding rule.

They DO make very good back scratchers though.  [big grin]

 

[woodbutcherbower]

Once upon a time I was installing some paintings in Soho for the artist Cy Twombly.

That just has to be a made-up name. Like Gaylord Focker.

 

[Michael Kellough]

Once upon a time I was installing some paintings in Soho for the artist Cy Twombly.

That just has to be a made-up name. Like Gaylord Focker.

You are right and I was wrong. He grew up in Virginia and his given name was Edwin Parker. The nickname Cy (after Cyclone Young) was inherited from his father who had been a professional baseball player.

The paintings. Fifty Days at Iliam Now owned by the Philadelphia Museum of Art

 

[tsmi243]

One of them built the minbar and the other made the mihrab.

Had to read this twice.... was wondering how all his Muslim friends were gonna feel about a mini-bar in the mosque? 

 

[Bob D.]

"The paintings. Fifty Days at Iliam Now owned by the Philadelphia Museum of Art"

My grandson scribbles like that. Maybe he's a budding artist.

I better stop tossing all his stuff stuck on the fridge and stash it
away for when he becomes famous then sell as his 'early works'
at a hefty price. 

 

[mino]

Just a short nip.

When your tape is 1.5 mm off over its /say/ 5-meter run, that is NORMAL for a casual "non-Class 1" tape /EU parlance/.

The /European/ norm for "Class 1" is up to 0.6mm off on a 5-meter tun for tape measures. Twice that for "Class 2". Tape measures are generally seen as "approximate" in the metrology world due to their mechanical susceptibility to be stretched or otherwise compromised easily.

That is why it is best to get one Class 1 accurate tape AND have it calibrated against a known-good reference. Good metrological shops offer this as a matter of course.

THEN use that tape as a point-of-reference for all other measuring tools you use.

Now, you say, why calibrate. Is it not overkill ?
Well, the problem with tape measures is they are fragile so can be "stretched" on the begining and "shrunk" at the end etc. So a 2  meter tape can measure 1001mm for real 1m but still measure a very good 2000.5 mm over the 2 meters. If this happens, your two "1000 mm pieces" will suddently add up to 2002 mm ... Yes I have seen this in tapes.

When you have at least one calibrated, you can spare it and then buiy cheapo ones, being able to easily check which are good and which are crap. Without a known-reference, you are in the blind.

Then there is another problem - materials size changes with temperature A LOT. And your metal tape shrinks and expands with temperature at a different rate than wood does. So if you want accurate fits on a project, you want to measure all parts around the same temperature. I.e. you do not want to be cutting your boards to size outside when it is cold and cutting shelving inside at 25C, for example.

All above is the same for Metric as for Imperial. Of course.
But it is IMO more "visible" as the common unit is 1 mm while with Imperial that would be just 0.04" and people psychologically care more about "whole unit off" than "just a fraction off" even if it is the same actual length.

 

[mino]

One add for LR32 that was mentioned here on why not 25 etc.

Well, guess how much is 2*2*2*2*2 or 2^5, yes, 32.

So you can divide 32 into 16+16 then 8+8+8+8 then ... so this is much better than, say 100.

In a way, "32mm" system is actually "x*2^n" system where everything is a multiple of (a power of 2) and while the base unit is 32, one can easily divide it up into smaller base units that align to base-32 without fractions.

You can divide 100 into 50x2 then 25x4 and then you are screwed, you need to start dividing by 5 which is rarely desired.

Thanks to this the "32 system" completely avoids non-whole units when referenced in milimeters. Need 3/4 of something, no issue => 3/4*32 = 24. Need 3/4 (of 1/2 )of something ? No issue. 3/8*1/2*32=12. Need another half od that. No issue, 12/2=6mm ...

Why not 64? Well, that would be too big for a "base" distance while 16 would be needlessly small. When one works in 32mm system, one can easily count everything in multiples of 32mm, and simplify all the maths immensely as a result. Kinda like the "simplicity" of inches without the complexity of Yards and non-whole fractions when converting to mm.

 

[Coen]

Exactly Crazyraceguy, I remember this was a part of transition to metric (48x98mm)
Then I thought, why on earth not 50x100? so much easier - then someone said it’s about adding with other dimensions and drying of lumber.. slippery slope - I think that’s why 2x4 stayed.. easy to remember and speak out - and visualise.

Isn't Metal Stud nice eh... 50mm actually being 50mm.

Makes me wonder... the USA being the country of litigation... has anyone sued yet over these timber sizes?