Resawing

[Roy Harding]

Similar to Wayne in Australia, I was in school when Canada switched to metric. I remain comfortable in either system - most of my fences and measuring devices have both scales displayed on them.

It's interesting to note that when I'm designing furniture from scratch I work in metric, but when designing a construction project (a wall, or building a room or a shed and so on), I work in imperial. This is probably because most of our construction materials either come from the USA, or are also exported to the USA, so that 16" OC or 24" OC remains the logical dimensions to use - converting to mm would be silly when using materials sized to work in inches.

I still "think" in pounds and ounces when it comes to body dimensions (weight, height etcetera), but in metric when it comes to distances (kilometres instead of miles, metres instead of yards) - probably because our road signs are in km, not to mention 25 years in the military, sweating out ruck marches measured in kms, and using maps scaled in metres.

I don't think either system is inherently "easier", and ones preference for one over the other is an entirely personal and subjective choice. One's ability to "feel" the dimensions is not, at least in my case, dependent upon which system is in use. I'm capable of "feeling" that a board is 3 mm thick, as easily as "feeling" that it is ⅛" thick.

I have learned, however, that if one is using plans delineated in inches, it is never a good idea to convert to mm when in the shop - pick a system and stick to it from the drawing board (or computer screen) right through to completion.

[Rod Sheridan]

I disagree Rudy, I converted to metric for furniture construction and find it far easier to use than imperial.

You can easily tell 18mm from 19mm by comparison, just like you can tell 3/4" from 47/64" by comparison.

What you cannot do is tell without using any measuring tools, whether a single piece is 18mm, 19mm, 3/4" or 47/64".

Regards, Rod.

[Martin Wasner]

My sentiments exactly! Metric is for great folks that cannot learn multiplication
facts up to 12.

I like fractions. They are easy to do the math in your head with, and here's a fun fact, a fraction has a decimal equivalent that can be applied to the metrical system, but as you sorta say, you need to use factors of 2,4,8,16,32, etc for the fractions to be useable.

My biggest complaint with si is having only one unit of measure for length. That's just bizarre to me

[Rod Sheridan]

My biggest complaint with si is having only one unit of measure for length. That's just bizarre to me

Martin, mm, m and km are the commonly used metric length measurements, based upon the metre.

We have the same in Imperial, I'm sure you use inches, feet and miles, all of which are based upon the yard, which is defined as a certain part of a metre.

So while both systems only have one unit of length, they also have many units based upon a fraction or a multiple of a unit.....Regards, Rod.

[Martin Wasner]

A millimeter is 1/1000th of a meter. Milli=.001
A kilometer is 1000 meters. Kilo=1000
A meter = 1 meter

Whether you say kilometer or thousand meters, it's the same thing. So no, you do not have different units.

Professionally, I don't know what anything over an inch is, cabinet makers for whatever reason function only on inches here. Any unit of measure can be converted to another. 5280 feet to a mile, 16½ ft to a rod, 3 feet to a yard, 12 inches to a foot, 25.4 inches to a meter... [edit]- 39.37 inches to a meter. I had the wrong number in my head.

[mreza Salav]

I do - because metric claims to be scientific, but is actually totally arbitrary; while imperial is usually described as nutty and arbitrary but actually evolved through use to fit what we do and how we work.

A month or so ago I would have agreed that metric is better, however that was before I really thought about it and discovered how hopelessly out of sync with my own thought and work patterns tenths of inches is. Now I'm more inclined than not to argue that imperial is better because it fits with (and evolved to support) human work and perceptional patterning. Notice, please, that I give no credence to the easier arithmetic argument: fractions are not significantly harder to work with then powers of ten (i,.e. there is a difference, but it is not material).

As somebody who is grown up metric and now work with imperial and metric very easily and convert them very quickly (have a sense for both) I disagree to call metric "totally arbitrary". Your problem to think "tenths of inches" is because you are still thinking imperial.
Imperial is designed based on divisions by 2 (that's why you have 1/2, 1/4, 1/8, etc) whereas metric is based on divisions by 10 (1 meter = 10 decimeter = 100 centimeter = 1000 millimeter etc). Because we (humans) count in base 10 it is actually a lot more natural to consider measurement unit that is also base 10 (unless you are more comfortable to count in binary and write 1011 instead of 13).
Also, to think fractions are not hard to work with vs metric: without calculators, compute the following sums and tell us which one was faster/easier: 13' 5" 17/64 + 20' 8" 97/128" vs 4096mm + 6318mm

Again, I am very comfortable with both and because tooling is mostly imperial here I mostly work with imperial and rarely (almost never) use calculators.
Regardless, metric is the system that is used pretty much everywhere else in the world and if you ask the rest of the world they think it is more natural (and rightfully).

[Martin Wasner]

A cabinet maker wouldn't do 13' 5-17/64". It'd be 161-17/64"

You can make that a decimal if you like too, 161.265625" but what kind of psycho working with wood expects six decimal places of accuracy? It's probably going into a house, not outer space. LOL


What's easier to add in your brain? 32-7/8 + 12-7/16 or 32.875+12.4375. You know, realistic numbers.

[Martin Wasner]

Fractions exist in the metric system too, but good like finding a measuring device based around it in a sensible way.

[mreza Salav]

Measurement units are not developed to be used in cabinet making, or woodworking, or any specific industry.
They are developed as standard to be used everywhere. The two numbers were not intended to be in any specific field.
If your brain is wired to think in fractions of 1/2, 1/4, 1/8 (powers of 1/2) then you try to "read" things that are close to powers of it.
For me (as a mathematician) there is not much of the difference between the two (I often do the additions faster than a person with calculator at hand) but to think imperial is easier to work is just as surprising as somebody telling me they are more comfortable working with binary numbers
(101101 + 11101001) instead of decimal (45 + 233).

[rudy de haas]

Also, to think fractions are not hard to work with vs metric: without calculators, compute the following sums and tell us which one was faster/easier: 13' 5" 17/64 + 20' 8" 97/128" vs 4096mm + 6318mm
.

This example does what it's intended to do: show that fractions are harder. However, it isn't very realistic: i measure in 8ths most of the time, 16th some of the time, and 32nds when I'm imagining myself able to cut things to that tolerance. So (4 x 96 3/8th)+24 1/2 is more realistic, and much easier than 4096+6318 .

Think of this as a continuous approximation problem: if I keep making harder examples, and yours get easier we'll eventually find a level at which we agree that metric is simpler in concept but harder to use to some point and easier after that...

Then we can argue about how arbitrary each system is - and you will find yourself arguing that the geocentric world view inherent in defining the unit length in terms of the length of the meridian through Paris is less arbitrary than defining it in terms of human attributes like stride length or thumb width (i.e. that geocentrism is more scientific than humanism).

All joking aside, I'm starting to convince myself that imperial measure may actually be better because it fits human needs and human perceptions while metric [length measurement] is simpler but divorced from ergonomics and only pretentiously less anthropocentric because ultimately Ptolemaic.

[Martin Wasner]

Measurement units are not developed to be used in cabinet making, or woodworking, or any specific industry.
They are developed as standard to be used everywhere. The two numbers were not intended to be in any specific field.
If your brain is wired to think in fractions of 1/2, 1/4, 1/8 (powers of 1/2) then you try to "read" things that are close to powers of it.
For me (as a mathematician) there is not much of the difference between the two (I often do the additions faster than a person with calculator at hand) but to think imperial is easier to work is just as surprising as somebody telling me they are more comfortable working with binary numbers
(101101 + 11101001) instead of decimal (45 + 233).

As a mathematician you must agree that basic addition & subtraction is wicked easy in your head with fractions versus adding a number and up to four decimal places.

I get it though, you have an abstract view of measurements, I have a narrow application.

[Wayne Lomman]

To all of you, there is a third type of country as well - one that enabled Apollo 11 to be tracked while the USA was in shadow, not to mention that country providing the most desirable off shore posting for US military personnel (I used to work with them in the 90's). I could go on but I would remind you that I started this thread as a simple comparison of woodworking on opposite sides of the world. How a difference in measuring systems can be viewed as a threat to the world order is beyond me. Get a life.

[Martin Wasner]

But woodworking is my life! (We need a sarcastic font here)

[rudy de haas]

Measurement units are not developed to be used in cabinet making, or woodworking, or any specific industry.
They are developed as standard to be used everywhere..

That's the metric ideal, but evolved measures like imperial did develop to fit specific uses - and devolve the same way: hardly anybody still uses knots or stones, for example.

Thus the people who, over centuries of work, made the the transiitions from 1/2 to 1/4 and from 1/8th to 1/16th "standard" weren't thinking in powers of two (cf: russian peasant multiplication), they were codifying "about half that" and "maybe twice" by practice. For arithmetic powers of ten work nicely and make us think metric easier to work with for a wide range of uses, but both the numeric base (10) and the physical one for the meter are logical (abstract) rather than practical (evolved) - some wheelerite somewhere has to be defending octal and the wavelength of middle C at [their] STP as logically compelling in just the same way you proffer metric.

[Cody Colston]

There are differences in nomenclature even here within the US. What I call a flitch, most woodworkers nowadays would call a slab. To me, a slab is the outside, one side rounded, cut off a log. It's scrap to me. A flitch is a board/plank of any thickness with two natural edges. I think of resawing as slicing milled stock into thinner stock usually done with the band saw. Ripping is making stock narrower usually done with the TS.

Yes, it can be confusing at times when trying to understand when people are using different terms for the same thing but eventually it gets sorted out.

As for measuring, I use imperial but try to avoid measuring as much as possible. The fewer numbers flying around, the better. Marking stock in place or using story-poles and diagonal sticks is more accurate, IMHO. I used to work almost exclusively from plans (someone else's) but now build from my own "designs", usually just a very rough sketch. I have adopted Krenov's method of composing a piece, letting the wood and the desired "feel" dictate dimensions. I do a lot of mockups. Of course, I'm only a hobbyist and don't do production runs of anything. I can take my time and enjoy the process as much or more as the final result.