Imperial Vs metric

[Cato]

It's easy to forget what a royal PITA imperial measurements are compared to metric.

I'm doing a refresher on engine tuning ready for mapping the EFI conversion. That involves going over volumetric efficiency, air density etc. all of which I learned in metric. The info I'm working with is from a Kiwi outfit and it's very good. But. Jesus wept does imperial complicate things.

For example to convert cubic inches to cubic feet, multiply by 1728. To convert litres (already 'cubic') to cubic metres move the decimal point three to the left.

 

[Porkypine]

I'm from the imperial era, but I use both, I find metric better for small measurements, but feet and inches far more sensible for longer dimensions, metric gets crazy unwieldy numbers fairly quickly

 

[roofman]

It's easy to forget what a royal PITA imperial measurements are compared to metric.

I'm doing a refresher on engine tuning ready for mapping the EFI conversion. That involves going over volumetric efficiency, air density etc. all of which I learned in metric. The info I'm working with is from a Kiwi outfit and it's very good. But. Jesus wept does imperial complicate things.

For example to convert cubic inches to cubic feet, multiply by 1728. To convert litres (already 'cubic') to cubic metres move the decimal point three to the left.

Tell me about it, even basic stuff...when i was on the spanners in the states it was like "can you pass me a 126th 5/17th wrench wtf

 

[ajlelectronics]

I'm from the imperial era, but I use both, I find metric better for small measurements, but feet and inches far more sensible for longer dimensions, metric gets crazy unwieldy numbers fairly quickly

Oh yes. Many measurements are far better in real money, but there is room for both in what I do. As an aside, I had to teach my assistant how to measure 315mm on a steel rule yesterday!

 

[Chippie]

Educated in the 60’s on the Imperial workings of this world until we went to Metric in the early 70’s….
Physics and Chemistry obviously lent themselves to Metric for calcs.

Can’t remember what we used unit wise 1st year of my apprenticeship in the training centre….suffice to say the instrumentation courses were in PSI for Pressure…3-15 psi….
But then when I went abroad to work in South Africa…..it was all Bar and kPa….….

Now retired at home in the workshop it’s all mixed now….Inches or mm…it don’t matter…..I have sets of drills/ milling cutters for both, metric taps and dies, Imperial taps and dies ( BSW/BSF ) BA taps and dies and some American white where they couldn’t make up their minds, so they had imperial diameters but with 60 degree thread angles….

Its all good fun….

 

[Cato]

I'm from the imperial era, but I use both, I find metric better for small measurements, but feet and inches far more sensible for longer dimensions, metric gets crazy unwieldy numbers fairly quickly

The thing is with large metric numbers being converted to larger metric units it's so simple, so there aren't really any unwieldy metric numbers. None of this "468 pebbles to a horses fetlock" nonsense.

I find these days I use metric more and more because it's just quicker to do so. I say that having been educated in both, then started my apprenticeship in '83 and college was both but in the workshop imperial still ruled (see what I did there? ) but since then there's been a progression to almost exclusively metric.

 

[tom2207]

I only ever go out with younger women ,,


they measure everything in centimeters ...

 

[brightspark]

I only ever go out with younger women ,,


they measure everything in centimeters ...

thats what some blokes do i ask them if they do needlework and make clothes just use milimeters and meters tell someone it measures 1800 and they look at you blankly i use metric and imperial just look at the rule and which ever looks the quickest to see thats the one i use. the lathe is imperial so i use imperial measurments using the digi vernier calipers that convert both

 

[roofman]

So what size is a gnats d1k in metric? or convert a large inch or small inch

 

[brightspark]

So what size is a gnats d1k in metric? or convert a large inch or small inch

same as a midges dick either way

 

[tom2207]

Like a few here , Im of the age where I was caught in the cross over from imp to metric ,,, anything over a foot I think in feet and inches , I can picture 12ft no bother , but 3.8m I have to convert roughly in my head and then work in feet to get a scale , but under an inch its so much handier to work in mm
but its not the first time ive gone to get 8 feet of 100mm x 50mm box
same as 2 meters of 4x2 ... funny old world .

 

[tom2207]

same as a midges dick either way

give or take a smidge ,,, lol

 

[ajlelectronics]

So what size is a gnats d1k in metric? or convert a large inch or small inch

Many real units like inches and yards are based on real and everyday items, which is where the phrase "Rule of thumb" comes from.

 

[tom2207]

Many real units like inches and yards are based on real and everyday items, which is where the phrase "Rule of thumb" comes from.

buy your rope from a tall man in that case ,,,,

but sell it to short folk.

 

[Porkypine]

So what size is a gnats d1k in metric? or convert a large inch or small inch

Une coq de moucheron??

 

[Keithmac]

I watch a few American machinists and it just doesn't make any sense when they're working stuff out in imperial!.

 

[Dragnet]

There is a reason that every culture used a base other than ten when coming up with numerical systems, even if they had a concept of zero. The Babylonians used base 60! Base 12 for what we know as 'Imperial' for instance is far more useful than metric base 10 as it has more factors and can thus be broken down and multiplied or divided with more straightforward parts rather than recurring decimals. This makes mental arithmetic much simpler. For those brought up with base 10 like me, it initially seems very difficult, but as soon as I started investigating Imperial units I find myself using them a lot more for workshop-size projects. During my time in a Swedish university workshop, being able to use fractions in projects was a great boon. Many times I was setting up dividing a board or something that required equal parts and I'd have it marked out in inches while the Swedes had to get their phones out to use the calculator, then try to measure things to five decimal places.

It isn't chance that we have 12 months, 12 hours, 60 minutes etc. This worked for pre-calculator cultures for hundreds of years. I guess the volumes are more complicated, but perhaps if you were brought up with it and taught rigorously it would just be another dialect of the same language. It obviously didn't hold back Trevithick, Brunel, Watt, Davy etc. etc.

 

[Porkypine]

I've been known to use ancient Egyptian / Roman type measurements, like cubits and spans of the hand etc.
It's worth measuring certain dimensions on your body / hands for rough reference if you've not got a tape measure on you!

 

[roofman]

I've been known to use ancient Egyptian / Roman type measurements, like cubits and spans of the hand etc.
It's worth measuring certain dimensions on your body / hands for rough reference if you've not got a tape measure on you!

There are some customers who would take exception to whipping out a 9" meat rule when fitting a kitchen

 

[James1979]

There are some customers who would take exception to whipping out a 9" meat rule when fitting a kitchen

It’s obviously cold in the kitchens you work in