4 ms·

I agree that (at least part of) my preference comes from familiarity but I am not convinced that it is caused 100% by familiarity. I happened to see this brief

I agree that (at least part of) my preference comes from familiarity but I am not convinced that it is caused 100% by familiarity. I happened to see this brief interaction in a video [0] the other day that pretty accurately illustrates my point of view. In summary: 2 makers (one german, one american) working on a device are looking at parts in hand to design as they build and one says "...if you put this 15 millimeters in from the edge. about half an inch". They first physically see/feel the distance they believe to be correct is 1.5 or 15 metric units (cm or mm) or 1 imperial unit (half inch). This is the case I find comes up frequently for me. Measures where moving a cut to line up to whole cm is too far and I end up working with half and quarter centimeters or awkward counts of millimeters. Though, it is definitely possible that 15mm only felt right in that case due to familiarity with imperial measures and that 1cm or 2cm would have been fine. I guess the "trick" is that even though 1/16, 1/8, 1/4, and 1/2 inch are all technically divisions of an inch, they all function in practice as distinct whole units that are (typically) easily converted. So when you are doing work in that scale range you have many options to match what you are working with. Paper sizes are also another good example of what I am talking about. An imperial "letter" size page is 8 and 1/2 by 11 inches. To cut one in half in either direction, the calculation is easy: horizontal 8 divided by 2 is 4 plus 1/2 divided by 2 is 1/4 or vertical 11 divided by 2 is 5 and 1/2. The similar ISO size (A4) is 210mm x 297mm would be cut at 10.5cm or 14.85cm. Sure you could just pull two A6 out of the drawer instead of cutting one A4 but then you are using ISO216 as your units of measure instead of cm/mm. In terms of practicality, cutting material stock in half is a pretty basic operation. [0] https://www.youtube.com/watch?v=MxLOoriXkMc&feature=youtu.be&t=973 https://www.youtube.com/watch?v=MxLOoriXkMc&feature=youtu.be...

Jedd 6y ago
> 1.5 (cm) or 1 imperial unit (half inch). Can I ask why you consider consider 0.5 inches to be 'one unit' - but think 1.5 cm is not? For me, a unit is akin to atomicity. But units don't dictate what size something is or should be - that's what multiples are for. > Measures where moving a cut to line up to whole cm is too far and I end up working with half and quarter centimeters or awkward counts of millimeters. It's a poor tape measure that does not show mm. Similarly it would be a poor tape measure that does not show 1/32 of an inch. The fact that your measuring device shows these gradations doesn't mean your design needs to be aligned to any arbitrary subset of multiples / divisors though, surely? > I guess the "trick" is that even though 1/16, 1/8, 1/4, and 1/2 inch are all technically divisions of an inch, they all function in practice as distinct whole units that are (typically) easily converted. So when you are doing work in that scale range you have many options to match what you are working with. 1/16th of an inch isn't just technically a division of an inch. : ) When you're working down to something tiny, both measurement systems will be able to represent absolute distances just fine - do we agree on that? It's a matter of whether manipulating those numbers is easy or difficult (for me, working with wood almost always means working with integers - mm - so all calculations are delightfully easy). Refer my other post about the Leigh dovetail jig description of router bit and bush sizes - there's 4 different dividends in use in just that one short paragraph, so you have to convert them all to common denominators before doing any mental arithmetic with them.
- shuntress 6y ago
  > When you're working down to something tiny, both measurement systems will be able to represent absolute distances just fine - do we agree on that? Yes. I guess it was implied by omission but I don't think either system is bad. My original statement was: "I wouldn't call imperial measures 'broken'" > Can I ask why you consider consider 0.5 inches to be 'one unit' - but think 1.5 cm is not? >1/16th of an inch isn't just technically a division of an inch. : ) Because I don't think of 1.5 inches as 1 inch + 0.5 inches, I tend to think of 1.5 inches instead as three 1/2-inches. What I mean by stating that while 1/16 is (and 1/2, 1/4, 1/8 are) "technically" divisions of the inch, they are _practically_ (or effectively) separate whole units that you step up or down to the same way you convert up or down between mm and cm. I find sub-dividing material (or design) by a power of two to be very common. Working with metric units, this tends to always lead to handling multiples of 5 which I tend to find more difficult than handling multiples of 2. Working with imperial inches and subdivisions of an inch in this way (for "normal" sized projects of the type mentioned in previous comments) means there are more options to match "whole" units to the specific measurement and you generally make new measurements in your work by changing units and adding/subtracting integer values of that unit. It is literally practical because it was derived from existing practices and matches them inherently.

Jedd 6y ago

> 1.5 (cm) or 1 imperial unit (half inch). Can I ask why you consider consider 0.5 inches to be 'one unit' - but think 1.5 cm is not? For me, a unit is akin to atomicity. But units don't dictate what size something is or should be - that's what multiples are for. > Measures where moving a cut to line up to whole cm is too far and I end up working with half and quarter centimeters or awkward counts of millimeters. It's a poor tape measure that does not show mm. Similarly it would be a poor tape measure that does not show 1/32 of an inch. The fact that your measuring device shows these gradations doesn't mean your design needs to be aligned to any arbitrary subset of multiples / divisors though, surely? > I guess the "trick" is that even though 1/16, 1/8, 1/4, and 1/2 inch are all technically divisions of an inch, they all function in practice as distinct whole units that are (typically) easily converted. So when you are doing work in that scale range you have many options to match what you are working with. 1/16th of an inch isn't just technically a division of an inch. : ) When you're working down to something tiny, both measurement systems will be able to represent absolute distances just fine - do we agree on that? It's a matter of whether manipulating those numbers is easy or difficult (for me, working with wood almost always means working with integers - mm - so all calculations are delightfully easy). Refer my other post about the Leigh dovetail jig description of router bit and bush sizes - there's 4 different dividends in use in just that one short paragraph, so you have to convert them all to common denominators before doing any mental arithmetic with them.

shuntress 6y ago
> When you're working down to something tiny, both measurement systems will be able to represent absolute distances just fine - do we agree on that? Yes. I guess it was implied by omission but I don't think either system is bad. My original statement was: "I wouldn't call imperial measures 'broken'" > Can I ask why you consider consider 0.5 inches to be 'one unit' - but think 1.5 cm is not? >1/16th of an inch isn't just technically a division of an inch. : ) Because I don't think of 1.5 inches as 1 inch + 0.5 inches, I tend to think of 1.5 inches instead as three 1/2-inches. What I mean by stating that while 1/16 is (and 1/2, 1/4, 1/8 are) "technically" divisions of the inch, they are _practically_ (or effectively) separate whole units that you step up or down to the same way you convert up or down between mm and cm. I find sub-dividing material (or design) by a power of two to be very common. Working with metric units, this tends to always lead to handling multiples of 5 which I tend to find more difficult than handling multiples of 2. Working with imperial inches and subdivisions of an inch in this way (for "normal" sized projects of the type mentioned in previous comments) means there are more options to match "whole" units to the specific measurement and you generally make new measurements in your work by changing units and adding/subtracting integer values of that unit. It is literally practical because it was derived from existing practices and matches them inherently.