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When you say “imperial system” you almost certainly mean US Customary Units. These are not the same system. The United States has never used the Imperial Syst

by mulmen 5y ago

When you say “imperial system” you almost certainly mean US Customary Units. These are not the same system. The United States has never used the Imperial System. Also, US Customary Units have been defined in terms of SI units since 1893. Personally I don’t find multiplying by two any harder than multiplying by 10. https://en.m.wikipedia.org/wiki/United_States_customary_units https://en.m.wikipedia.org/wiki/United_States_customary_unit... https://en.m.wikipedia.org/wiki/Mendenhall_Order https://en.m.wikipedia.org/wiki/Mendenhall_Order

eternityforest 5y ago
Multiplying by all numbers is equally easy or hard with calculators, the problem is fractions break UIs. Try adding 3/16 plus 1/2. On a calculator that is three separate operations, and if the output is decimal, you have to convert back to a fraction. And when automated systems convert to fractions, the amount of error is not obvious. With decimals, the computer just adds more digits unless you limit it to a certain number of places. It is safe to add a few extra because you can ignore them. With fractions the whole point is smallish integers. If a computer says 3/8 inch I have no idea if it's really 3/8 or if its 11/32 and the computer rounded. It can't just always show the value in 128ths of an inch because... nobody knows what those are and rulers aren't marked that way. So to have a computer display fractions means understand how it does so, it's not obvious(Unless you displayed explicit error values, which would be pretty great) The whole thing came from a time when very skilled humans with no tech did everything themselves and seems optimized for that at the expense of everything else. Decimals way easier for applications where all the math is 100% done by the CAD program.
- mulmen 5y ago
  Nobody is using 128ths of an inch. That’s 7 thou. Realistically anything smaller than a 32nd is going to be in thousandths of an inch and using specialized tooling. 3/16 + 1/2 is 3/16 + 8/16 which is 3+8 or 11/16. That’s simple arithmetic. No calculator needed.
  - eternityforest 5y ago
    No calculator needed assuming you can remember multiple intermediate variables or have the conversions memorized. It's a great "power user" system for skilled professionals in the pre computer age who practiced with it regularly, and it works well in things like woodworking where you still have a lot of things done on paper or just in someone's head. It's not the best for CAD first workflows, when you're trying to model everything down to where to clamp the edge guide blocks for the saw, and changing something without changing the model and confirming it will all fit isn't a thing. In 3D printing you get down to 0.4mm or occasionally even 0.2mm gaps between things, although none of it is really an exact science, and you assume some sanding may be needed to make things fit unless you have an amazing tuned printer. But I suppose woodworking is less of an issue, because you're probably not going to get even 1/16th precision by hand unless you're really skilled, in which case you probably have fractions memorized.

by mulmen 5y ago

eternityforest 5y ago

Multiplying by all numbers is equally easy or hard with calculators, the problem is fractions break UIs. Try adding 3/16 plus 1/2. On a calculator that is three separate operations, and if the output is decimal, you have to convert back to a fraction. And when automated systems convert to fractions, the amount of error is not obvious. With decimals, the computer just adds more digits unless you limit it to a certain number of places. It is safe to add a few extra because you can ignore them. With fractions the whole point is smallish integers. If a computer says 3/8 inch I have no idea if it's really 3/8 or if its 11/32 and the computer rounded. It can't just always show the value in 128ths of an inch because... nobody knows what those are and rulers aren't marked that way. So to have a computer display fractions means understand how it does so, it's not obvious(Unless you displayed explicit error values, which would be pretty great) The whole thing came from a time when very skilled humans with no tech did everything themselves and seems optimized for that at the expense of everything else. Decimals way easier for applications where all the math is 100% done by the CAD program.

mulmen 5y ago
Nobody is using 128ths of an inch. That’s 7 thou. Realistically anything smaller than a 32nd is going to be in thousandths of an inch and using specialized tooling. 3/16 + 1/2 is 3/16 + 8/16 which is 3+8 or 11/16. That’s simple arithmetic. No calculator needed.
- eternityforest 5y ago
  No calculator needed assuming you can remember multiple intermediate variables or have the conversions memorized. It's a great "power user" system for skilled professionals in the pre computer age who practiced with it regularly, and it works well in things like woodworking where you still have a lot of things done on paper or just in someone's head. It's not the best for CAD first workflows, when you're trying to model everything down to where to clamp the edge guide blocks for the saw, and changing something without changing the model and confirming it will all fit isn't a thing. In 3D printing you get down to 0.4mm or occasionally even 0.2mm gaps between things, although none of it is really an exact science, and you assume some sanding may be needed to make things fit unless you have an amazing tuned printer. But I suppose woodworking is less of an issue, because you're probably not going to get even 1/16th precision by hand unless you're really skilled, in which case you probably have fractions memorized.