Folks Hate The Metric System

[tbellemare]

How difficult would it be to calculate three equal parts of 1 meter using Imperial measurements?

If I were designing something that was 100" using the Imperial measurement system and I wanted 3 equal parts with standard machining tolerance, I would likely describe them as 33.333" +/- .015".

I don't see mechanical engineering functions as supporting the Imperial system. I see greed as supporting it.

Tom

 

[tallgrass]

in a machine shop before the digital revaluation of measurement you would use calipers and gauge blocks and sine bars. in fact i have seen wire frequencies used to measure distances. in the metric system you are stuck with a system of units of ten. in the standard system you can decide what units you wish. 64th ,32nd, what ever, not only that you can stay in the ratio and not convert to decimal and keep it all fractions. also there are more factors of 12 than ten. not only that if you want you can use an engineers rule which is broken into tens . to me it is just a tool. not better or worse, just different.

i actually find them both useful.

but i think you are asking for trouble if you combine the systems. as i said i use both but i do not combine them in a project and i never convert them back and forth.

if using one system makes one feel special and better than someone using another system than than fantastic, may you find great happiness

 

[VictorL]

Sound wisdom tallgrass.

A company that I worked for was under pressure to convert it's manufactured products to the global standard (metric).  It also had pressure from U.S. customers to have their custom machines built with imperial dimensions.  The decision was made to continue with imperial and to also build the export machines in metric.  I spent over a quarter million dollars for precision measuring tools alone.  Most all of the machine tools were CNC so they could handle both systems.  A huge early mistake was to "dual dimension" the mfg. drawings -- this caused countless mistakes misreading the drawings and in turn scrapping parts.  We found a number of old school machinists that would sit at their bench converting metric drawings to imperial & writing the dimensions on the drawings - more mistakes!  I could go on & on with problems the company had but I wholly agree with tallgrass -- pick a system and stick with it as much as possible.    The metric system really is very simple however most mistake occur when converting and switching back & forth.   

Hmm. I don't know what kind of equipment you producing, but why you don't build it in metric only, and have imperial dimensions in the documentation only?  
Nobody will puzzled with 'mounting holes distance  29 13/64" ' As I understand you need precise measurement only when installing equipment on site. Modern electronic scales can show distances in any units such as millimeters, foots, fingers, name your own.  

 

[VictorL]

i do find it frustrating that the metric system being a 10 base system has issues when measuring geometry where ratios are so easy and i can decide when and how much rounding error i am will do deal with. for example if i have an object that happens to be 1 meter and i simply want to turn into three pieces i am screwed simply because of the ten base system .or opposite, i want to make 3 units that add up to one meter. i am glad the Greeks did not have it ...i wonder what their beautiful ratios would look like if it all had to be units of ten limited to what they could resolve?i can not imagine how hard it was before the digital age.

If you divide 1 meter, you'll get 333.33 mm. Why should you divide one meter only?  999 mm is better number for dividing by 3 or 1200mm or 1500mm or 300mm.

Here is sample how to measure everything in anything.

 

[mastercabman]

i do find it frustrating that the metric system being a 10 base system has issues when measuring geometry where ratios are so easy and i can decide when and how much rounding error i am will do deal with. for example if i have an object that happens to be 1 meter and i simply want to turn into three pieces i am screwed simply because of the ten base system .or opposite, i want to make 3 units that add up to one meter. i am glad the Greeks did not have it ...i wonder what their beautiful ratios would look like if it all had to be units of ten limited to what they could resolve?i can not imagine how hard it was before the digital age.

If you divide 1 meter, you'll get 333.33 mm. Why should you divide one meter only?  999 mm is better number for dividing by 3 or 1200mm or 1500mm or 300mm.

Couldn't agree more

 

[RONWEN]

Sound wisdom tallgrass.

A company that I worked for was under pressure to convert it's manufactured products to the global standard (metric).  It also had pressure from U.S. customers to have their custom machines built with imperial dimensions.  The decision was made to continue with imperial and to also build the export machines in metric.  I spent over a quarter million dollars for precision measuring tools alone.  Most all of the machine tools were CNC so they could handle both systems.  A huge early mistake was to "dual dimension" the mfg. drawings -- this caused countless mistakes misreading the drawings and in turn scrapping parts.  We found a number of old school machinists that would sit at their bench converting metric drawings to imperial & writing the dimensions on the drawings - more mistakes!  I could go on & on with problems the company had but I wholly agree with tallgrass -- pick a system and stick with it as much as possible.    The metric system really is very simple however most mistake occur when converting and switching back & forth.   

Hmm. I don't know what kind of equipment you producing, but why you don't build it in metric only, and have imperial dimensions in the documentation only?  
Nobody will puzzled with 'mounting holes distance  29 13/64" ' As I understand you need precise measurement only when installing equipment on site. Modern electronic scales can show distances in any units such as millimeters, foots, fingers, name your own.  

If only life were that simple...  [smile]  The machines were extremely complex electro/mechanical/hydraulic systems.  The customer documentation would include manuals of repair parts, etc. but certainly no dimensioned drawings.  Customers typically stock a large inventory of all sorts of repair parts -- as an example (imperial) fasteners, pins, hoses, etc.  Obviously they wouldn't be happy to hear with the purchase of a metric machine (~$2M) they would also have to double the repair parts inventory to support both old and new machines that have a typical life cycle of 15 to 20 years.  
Some companies choose to go the route of "soft" metrification where ~99% of the product stays imperial but documentation, etc. is metric -- as an example a 1.000" diameter shaft is listed as 25.4mm.  Most European companies want no part of that nonsense.  

 

[tbellemare]

Using a CNC machine, it doesn't matter what the dimensions are or what the units are. The incredibly vast majority of metal machining and production style (or big shop) woodworking is done on CNC machines. What matters in metal machining to achieve results within tolerance, is the process. The same is true when machining wood.

If you're designing something that you are going to make using non-CNC machining methods, as the previous posts pointed out, it only makes sense to make it work out to even numbers. There is no inherent advantage to having multiples of 3 or 4 in the equation.

We are taught from 1st grade to think in base ten systems. In my elementary education, I wasn't taught to use fractions until later. I'm good at it but it's more difficult than just using decimal based calc's.

Ron posted while I was writing this so I'll address his post here...

I completely agree with you, Ron. There is a huge legacy machine and spare parts issue. The only way to break the stranglehold of such things is to agree as a nation. We can't agree on anything even if it cripples us to not agree.

Tom

EDIT: I own a nice Pickett slide rule that I bought as a sophomore in High School. It is base ten and was my first "calculator". I used to be REALLY fast and would spend significant time fine tuning it for speed. All of the precision measuring instruments I've used are in decimal equivalents.

 

[Joe Jensen]

I don't hate metric, I actually like it better.  I hate having mixed systems.  Sucks, some tools imperial, some metric. I have like 200 router bits, all imperial.  My Felder Slider has both, the shaper cutters are Italian and metric.  Most sheet goods are now actually metric and not imperial.  Lets just shoot the imperial system and get on with life.  Heck, most everything we buy in the US is now made in Asia, where the baseline is metric.

The worst example of cross systems was a Powermatic tool I bought new in 1990.  Complete crazy fasteners.  Most were metric threads with heads that were intended to be imperial, but they were basically the closest they could get in their metric world.  No wrench really fit.  Swapped them all for true metric heads and life was ok.  I think the Taiwanese factory was confused and Powermatic must have specified imperial bolts. That became imperial heads on metic bolts.

 

[andy5405]

I have always been amazed that the country that put a man on the moon over 40 years ago is still using imperial so much. It just doesn't make sense to a Brit. That said there are some things we will never change. We will always drink beer in pints, anything else would be unthinkable. We still think in miles as well but other than a few things it's a metric world here. Oh and it is obviously silly to drive on anything other than the left!

 

[RONWEN]

I have always been amazed that the country that put a man on the moon over 40 years ago is still using imperial so much. It just doesn't make sense to a Brit. That said there are some things we will never change. We will always drink beer in pints, anything else would be unthinkable. We still think in miles as well but other than a few things it's a metric world here. Oh and it is obviously silly to drive on anything other than the left!

I've been to the UK several times and usually ask why the roads are driven on the left -- I've gotten about as may different answers as times asked.  It does seem to go back to the around 1300 A.D at the request of the Pope. 
I admire the efficiency of the clockwise roundabouts in England, a much better way to move busy traffic.  I suppose it would be possible for the U.S. to create counter-clockwise roundabouts instead of our silly 4-way stop intersections -- that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

 

[jonny round boy]

that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

You see - you got rid of us, but you obviously regret it and are desperate to hang on to some vestige of your British heritage....

That's why you still use imperial! [poke]

 

[Ken Nagrod]

I have always been amazed that the country that put a man on the moon over 40 years ago is still using imperial so much. It just doesn't make sense to a Brit. That said there are some things we will never change. We will always drink beer in pints, anything else would be unthinkable. We still think in miles as well but other than a few things it's a metric world here. Oh and it is obviously silly to drive on anything other than the left!

I've been to the UK several times and usually ask why the roads are driven on the left -- I've gotten about as may different answers as times asked.  It does seem to go back to the around 1300 A.D at the request of the Pope. 
I admire the efficiency of the clockwise roundabouts in England, a much better way to move busy traffic.  I suppose it would be possible for the U.S. to create counter-clockwise roundabouts instead of our silly 4-way stop intersections -- that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

Funny, in New Jersey, all they've been doing is getting rid of "circles" or round-a-bouts and replacing them with large multi-lane intersections due to the traffic.

 

[Steve R]

that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

You see - you got rid of us, but you obviously regret it and are desperate to hang on to some vestige of your British heritage....

That's why you still use imperial! [poke]

JRB,

Actually we have messed it up even more.....   Go to a conversion site..... and you will see US gallons...and Imperial gallons....  [doh]  When living in Ireland for a year.... I found that out when a guy told me their gas would cost so much US$ a gallone and told him no.... that's imperical.... we have US gallons... and it got ugly from there... could have been the 8 Guinness he had.... [eek]

Cheers,
Steve

 

[Alan m]

that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

You see - you got rid of us, but you obviously regret it and are desperate to hang on to some vestige of your British heritage....

That's why you still use imperial! [poke]

JRB,

Actually we have messed it up even more.....   Go to a conversion site..... and you will see US gallons...and Imperial gallons....  [doh]  When living in Ireland for a year.... I found that out when a guy told me their gas would cost so much US$ a gallone and told him no.... that's imperical.... we have US gallons... and it got ugly from there... could have been the 8 Guinness he had.... [eek]

Cheers,
Steve

whats all that about. make up yer mind/ if ye want one pick one and not make up an in between.
what is the reason for the difference

 

[Steve R]

I have always been amazed that the country that put a man on the moon over 40 years ago is still using imperial so much. It just doesn't make sense to a Brit. That said there are some things we will never change. We will always drink beer in pints, anything else would be unthinkable. We still think in miles as well but other than a few things it's a metric world here. Oh and it is obviously silly to drive on anything other than the left!

I've been to the UK several times and usually ask why the roads are driven on the left -- I've gotten about as may different answers as times asked.  It does seem to go back to the around 1300 A.D at the request of the Pope. 
I admire the efficiency of the clockwise roundabouts in England, a much better way to move busy traffic.  I suppose it would be possible for the U.S. to create counter-clockwise roundabouts instead of our silly 4-way stop intersections -- that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

Funny, in New Jersey, all they've been doing is getting rid of "circles" or round-a-bouts and replacing them with large multi-lane intersections due to the traffic.

It was Napoleon that changed things to having on coming traffic on the left.... Why.... because he was left handed!  Which meant he was more able to defend himself... under the normal have oncoming traffic  on your right he lost. He wanted it changed so he could draw his sword from your his right side and use his strong arm to fight off an attack. Righties lost....

We don't have to go into the whole English and French.... love/hate thing....

Cheers,
Steve

 

[Steve R]

that will probably happen in about the same century that we finally get rid of imperial units (thank you very much British Empire!).  [wink]

You see - you got rid of us, but you obviously regret it and are desperate to hang on to some vestige of your British heritage....

That's why you still use imperial! [poke]

JRB,

Actually we have messed it up even more.....   Go to a conversion site..... and you will see US gallons...and Imperial gallons....  [doh]  When living in Ireland for a year.... I found that out when a guy told me their gas would cost so much US$ a gallone and told him no.... that's imperical.... we have US gallons... and it got ugly from there... could have been the 8 Guinness he had.... [eek]

Cheers,
Steve

whats all that about. make up yer mind/ if ye want one pick one and not make up an in between.
what is the reason for the difference

Alen

go to http://www.csgnetwork.com/fuelvolumeconverter.html

and you will see one US Gallon is 0.8327 Imperial gallons or 3.785411784 Liters...

Why?.....  Sorry don't know......

Just like Churchill said two countries separated by a common language. 

Cheers,
Steve

 

[tallgrass]

got to the moon with standard....

so who here uses the mm as the smallest unit and if so how do you accurately measure and mark a smaller unit. in your shop,repeatably.

 

[jonny round boy]

got to the moon with standard....

so who here uses the mm as the smallest unit and if so how do you accurately measure and mark a smaller unit. in your shop,repeatably.

Most metric steel rules are marked in 1/2mm increments. Most tapes are just marked in 1mm increments, but it's easy to place your mark to a 1/2mm by simply placing your mark half-way between the 1mm marks. It's also quite easy to 'guesstimate' to 1/4mm, but who really needs that level of accuracy?

TBH, very little I do really needs to be more accurate than a mm. There's no real point trying to mark to 1/2 or 1/4mm when a tape measure might be that far out anyway.

Anything that really needs a high level of accuracy would be marked directly from one piece to another, rather than measured & marked (if you know what I mean).

 

[VictorL]

so who here uses the mm as the smallest unit and if so how do you accurately measure and mark a smaller unit. in your shop,repeatably.

Could you please give example? How do you mark with 1/64 and 1/128 accuracy in your shop?

 

[tbellemare]

I can't think of a reason to do so. Can someone please describe a reason why one would need to define any aspect of a project in smaller increments than 1mm?

I'm not asking for shims, foil, or other such stuff either.

Thanks in advance,

Tom