Imperial measurement

[marcros]

i wonder if that is why i prefer it- it makes me think that bit more and double check everything. And fractions are often easier to do mental arithmatic on than millimetres are.

 

[condeesteso]

And fractions are often easier to do mental arithmatic on than millimetres are.

It's a good thing we are not all the same! I grew up imperial but now work metric almost entirely - I can halve (or thirds, on a Barocca day) 63mm far quicker than say 2 and 19/32nds (not the same thing, it's just an example).
But I have noticed two occasions for imperial: benches are for me overall inches, but round numbers. They are as long as you fancy, but 33" high (for me) and 21 or 22" deep.
And the various wood yards... they pretend to be metric but I watch them doing the conversion as we speak about a board. I'm sure most yards still cut imperial, then call it the metric equivalent. It will be a few years yet before the yards truly adopt metric I reckon.

 

[Digit]

As far as I'm concerned it should be based on logic. I don't want my Beer in CCs and I don't want my injections in Gills!

Roy.

 

[marcros]

And fractions are often easier to do mental arithmatic on than millimetres are.

It's a good thing we are not all the same! I grew up imperial but now work metric almost entirely - I can halve (or thirds, on a Barocca day) 63mm far quicker than say 2 and 19/32nds (not the same thing, it's just an example).
But I have noticed two occasions for imperial: benches are for me overall inches, but round numbers. They are as long as you fancy, but 33" high (for me) and 21 or 22" deep.
And the various wood yards... they pretend to be metric but I watch them doing the conversion as we speak about a board. I'm sure most yards still cut imperial, then call it the metric equivalent. It will be a few years yet before the yards truly adopt metric I reckon.

1/3rds, I'll give you, although i think you have taken advantage with your example.

 

[SammyQ]

Tony? I concur! Sam

Wildman? See?

 

[adzeman]

Its interesting to read in these posts how man say they prefer the old Imperial measures especially for woodwork. This is because it was devised by builders I do not know if it was the masons or the carpenters way back in the Middle Ages when the Crusaders returned to blighty. Those guy's found arabic numbers easier to work with than the X's IV' and so on. At college (Leeds) we were taught Duo Decimals which are similar to Deco Decimals but have a base of 12 instead of 10. With a base of 12 you can describe a number more accurately in duo decimals, Have you ever queried why feet and inches are shown as 0' 0" these marks show which set is being described and can go on indefinately e.g. 0' 0'' 0''' 0''''' and so on. What we are short of is 2 extra numbers and those that are used internationally pror to 1971 were as follows 1. 3, 3, 4, 5, 6, 7, 8, 9, @ * 10. Sizes are not defined by size but by nature 4x3, 6x3 a brick an 8'0"x 4' 0" sheet of ply a 6 6 x 2 6 door rise and go of a stair ceiling heights I am sure you can think of others. All trades were taught this system except the pattern makers who were a 100% metricated (painfull) Muliplication was easy you only needed your two times table and heavens a betsy there were 12 pence in a shilling.

 

[Digit]

The metric system was introduced mainly as an attempt to discard all that had preceeded it, a sort of 'year zero'. The French revolution even had a 10 day week! Apparently that went down like lead balloon with the 'Citizens.'
In 'nature' 1.2.4.8 is much easier to work with than 1.2,5.5.10.
Some how I doubt that our European friends cut their birthday cakes in metric portions.

Roy.

 

[adzeman]

How nice to here from someone who has studied this subject. Yes eight is better The decimal system only uses 10 because we have 10 fingers. Apparently the Arabs icounted on their knuckles of which there are 12. Octupuses are very good mathamaticians can predict football games!. Now we have computers the binary system is used that is 2 fingers to Napoleon

 

[bugbear]

Sizes are not defined by size but by nature 4x3, 6x3 a brick an 8'0"x 4' 0" sheet of ply a 6 6 x 2 6 door rise and go of a stair ceiling heights I am sure you can think of others.

I'm not fully sure that 8x4 sheets of ply occur in nature!

BugBear

 

[JakeS]

I'm not fully sure that 8x4 sheets of ply occur in nature!

All the same, I think you'll find that they're a perfect integer number of Planck lengths in each direction! ;-)

 

[Cheshirechappie]

Imperial measurements are based on the human body, and on what used to be common activities. So a foot is about as long as a human foot, an inch was three barleycorns end to end, an acre was the amount an ox-team could plough in a day, a fathom is the length of a man's outstretched arms, a furlong is 'a furrow long' when ploughing, and so on. All very sensible if you haven't invented the tape-measure yet.

I used to listen the advice and obsessively separate imperial and metric measurements. In commercial and industrial work, that's vital to avoid confusion, but in the privacy of my own workshop I now quite happily mix both. If it's handy to make something 100mm x 2" I will.

By the way - I think the standard plywood sizes came about because they were made 6" wider and longer than you can conveniently get in your car!

 

[adzeman]

I am not a material technologist a worthy profession but the ply is knifed from a rotated log 8' 0" is probably 3 lengths out of a 25'0" long baulk (you can get 10' )"
and cutting the sheet in half to glue the across sheet. There will be a relationship between the length of the log and getting the makimum sheets out with the minimum of waste and the maximum of profit.

 

[Digit]

And a pint was supposed to be the capacity of a man's bladder!

Roy.

 

[condeesteso]

Just working on a cabinet today and needed the centre of a stretcher. Laid the steel rule down wrong side (imperial up) and noticed it measured 35 and a half and 3 and a bit Bits. The bit being about 1/3rd of a Bit - in fractions for consistency. I needed to check what bits (sorry, Bits) we were in here - turned out to be 16ths. That's why I like metric. I have an old steel rule somewhere calibrated in 10ths, 20ths, 8ths... down to an inch somewhere in 64ths. It opens paint tins quite well.

 

[Digit]

Would you have been better off with 906.4265 mm?

Roy.

 

[condeesteso]

Indeed Roy I surely would - let's call it 906.5... so easy 453.25. I did round it by 3 thou I admit but that's close enough for me... funny the rounding is done in thou :lol: I still do that a lot - .1mm is 4 thou, my smoother gets set to about 3 thou as a start-point. I'm English > I like imperial >it's just that it's a British Leyland measuring system.

 

[Digit]

Like I said earlier, I use both, but when the architect came up with dimensions for a house we planned on building with dimensions in thousands of mm it becomes plain ridiculous, and if you were transferring dimensions it matters not what the units are.
For long dimensions I transfer using an extendable clothes prop! Every dimension is one unit long! :lol:

Roy.

 

[adzeman]

Why all this measuring? did you not make a rod? or, put the peice of timber up to the work and mark off the dimension?

 

[condeesteso]

Agreed, I don't use rules much at all and think the rod approach and what looks right proportionally is far better. The finding of centre-point was just a rare example - i think a rule is useful for that. All the legs, stretchers and joint positions were taken from the first of each component - the most accurate rod.

 

[Sawyer]

Agreed, about rods; by far the best way to proceed with anything even remotely complex. But to make a rod, we first have to measure. There's no hiding place!!