52 replies to this topic

[gray_cat]

Does anybody know which measurement units are used in F1 car manufacturing - metric or imperial ?

I suspect metric, but don'y know for sure. If that is so (I mean metric is standard) it is interesting to know if F1 cars ever been designed on imperial system ?

[david_martin]

Undoubtedly metric today, but I guess it would have been Imperial for many of the UK based teams, probably up until the early 70's. Today I suspect it is a simple product of necessity. Universities in most parts of the world from which F1 engineers are drawn only teach their student in metric. This would dictate most design and manufacture would have to be done in metric.

[gray_cat]

Thank you

[MrAerodynamicist]

Metic, metric, metric - in general, the UK has happily accepted metric. The only reason not to switch to metric is old equipment, and I can't see F1 teams having but the latest toys to play with.

Oh, and Imperial sucks!

[Ray Bell]

I wouldn't mind betting there are imperial nuts, bolts and rod ends around somewhere....

[SalutGilles]

is imperial american, you know, 5/32nds? if so, it SUCKS HARD. when i'm working on my car, i don't appreciate having to reduce 6/32nds to it's lowest common form if i want to go up a size, while searing hot old runs down my arm. any idiot can go from 5cm to 6cm without third degree burns

[Ray Bell]

Try telling that to the Aero industry, and then think about where a lot of race car fasteners come from....

[rmw00]

Read in an article about the Jordan car a couple of years ago. They used what ever fastener best met their needs without regard to metric or imperial. They said it did make things more complicated, but that's life in F1.

[palmas]

Well, do not forget tyres.What is the rim size? 13" - not metric is it?

But I bet it is the only one.

[Ursus]

Sorry to dissapoint you palmas but the rims must be 328-332mm in diameter! (13in=330.2mm)

[MrAerodynamicist]

Originally posted by Ray Bell
Try telling that to the Aero industry, and then think about where a lot of race car fasteners come from....

IMO, the main blocks to metric are old equipment, and legacy support [if you built the original aircraft in imperial, then you pretty much have to build in imperial until you redesign the aircraft from scratch] However, I imagine that all design work in-house of the F1 teams is done in metric. As my sister works for Ilmor, next time I speak to her, I'll see what the situation is with them.

[palmas]

[Halfwitt]

From what I understand, the best thread to use for strength and durability (fatigue life) is Whitworth /BSW. There isn't a metric equivalent of this (as far as I know). So, I suspect that until there is a metric whitworth, people will continue to use this in critical areas.

Hurrah for Mr. Whitworth.

[Billy Gunn]

Whoooo there Mr Aerodynamacist!

Why do you think Imperial measurement sucks? Do I have to remind you the Imperial system is mathmatically superior to a 10 base system from the point of view of scaling?? As any draughtsman will tell you 1/5 th scale sucks, and you never ever draw components at 1/2 scale.

As for the Aero industry and metrication in engineering there is only one comment ~ it's a non starter. Why do they use Whitworth formula threads for highly stressed parts I ask you?

Even Mr Seller's thread system got it wrong, whereas Mr Whitworth was spot on; and he worked it out without the help of whizz bang computors. Just to placate the metricists out there the British Association thread system (known as BA!) is based upon a metric formula which is delightfully simple. For example the next size smaller is 90% of the previous larger size and the thread form is 73% of the former size; all based on 0BA which is a 6mm major diameter thread x 1mm pitch. Hence 1BA (the next size down) is 6 x 0.90 = 5.4mm M.Dia and the thread is 1mm x 0.073 = 0.73mm pitch!

Just tell me why you can't get a MJ diestock! and why they had to introduce the MJ tap!!

Bonus points for telling me who Mr. Sellers was!

Billy G

[MrAerodynamicist]

Ah, imperial does suck. So it has a few good points, it still sucks And system which has pounds per pound as a unit doesn't deserve respect. I'm just glad I've never had to work with slugs. (the unit kind, not the eat your garden kind)

[Billy Gunn]

Now what really sucks is a system designed around the available digits of your average (i.e. 10 digited) knucklehead! The imperial system on the other hand (!) has an expansive role in the development of mathmatical thinking for your Junior school kids - this is a proven fact. Children taught the Imperial measurement system grasp Octel, and Hexadecimal far easier than those who have been taught the metric system.
The only move to metrication within the States has been the Auto industry - and this was done to open up supply channels from foreign industries. In just about all other ares of engineering commerce metrication has virtually ceased.

If metric is so brilliant why don't computors use it??

And as Halfwit endorsed my earlier ascertation that Mr. Whitworth got it right, where is the MJ diestock?? and why did they have to introduce MJ in the first place; in fact why did they introduce UNJ??

[DangerMouse]

Decimal is convenient, as pointed out a lot of (especially whit-worth) sizes were based on sound engineering re maximising the strength of threads etc.

Now what really sucks is a system designed around the available digits of your average (i.e. 10 digited) knucklehead! The imperial system on the other hand (!) has an expansive role in the development of mathmatical thinking for your Junior school kids

Absolutely spot on BG. Ask any kid today to add up and they are flummoxed, all the old biddies can do complex calculations in their head. The British Code breakers in WWII were ordinary people off the street not mathematicians; The guy that devised the electronic programmable ALU for the worlds first electronic programmable computer (to break the said codes) was a uneducated post boy!

This is a true story…
I was in my local pub and ordered two packets of Crisps from the barman (a student doing an engineering degree.) He started to tap “45+45” into the calculator on the bar (yes really!) before he hit “enter” I said 90p, he looked astonished when he hit the enter key only to get the same result!

And yes that scares me! – if he ends up working for an auto company I’m gonna start walking!

[Ursus]

So Witworth do some solid engineering work, measuring things in imperial units.

The conclusion is naturally that imperial measurments are superior to metric measurments.

OR,
isn't it that sound engineering is sound egineering wether imperial or metric measurments are used.

BTW binary code and metrics are completely different things.

[gray_cat]

Originally posted by Billy Gunn
The only move to metrication within the States has been the Auto industry - and this was done to open up supply channels from foreign industries.

Looks like that is the case in other 'imperial' countries like UK - the growing dependency on hi-tech equipment and tools from 'metric' countries is forcing traditionalists to change their engineering habits

[Ray Bell]

Is Whitworth/BSW really so superior?

With the variety of threads available in Metric, I wouldn't have thought so.

And Billy Gunn, what the hell is MJ etc? The 'J' has me stumped, obviously 'UN' stands for 'Unified' as in UNC and UNF, a system with which I am well familiar despite owning Peugeots for 35 years (with Lockheed brake lines, mind you, in both 7/16 and 3/8 UNF).

According to Big Dave, who would love to join in this conversation (if only he could! What a lecture you'd all get!), Metric was only universal in that it made it possible for everyone to universally pick their own threads...

As for the younger generation lacking mental acumen due to the loss of brain exercise in learning and using the imperial systems, I have to agree. This is probably why our Antepodean lot have always been so well accepted in F1 teams - having been brought up with both.

[Ray Bell]

Originally posted by gray_cat
Looks like that is the case in other 'imperial' countries like UK - the growing dependency on hi-tech equipment and tools from 'metric' countries is forcing traditionalists to change their engineering habits

Bear in mind that Morris bought a large supply of equipment in the thirties or forties that led to the metrication of their engines.

Most people thought that the fine threads they used were BSW, however, and swore all the more...

MG TC owners should know this...

[desmo]

Nice to have you back BG.

Re: Mr Sellers, a quick look about revealed that William Sellers proposed in 1864 a standardized threading system based on a 60 degree thread form with flat crests and roots and pitches that are proportional to the diameters. This system appears to have evolved into the present-day American NC and NF threading standards.

By MJ, do you mean mechanical joint as used in piping and plumbing joints?

Fresh out of high school I purchased a basket case BSA A65 Lightning and was forced to confront a plethora of threading systems. When I took some mystery fasteners down to the university machine shop to test on their thread gauges, I was astonished to learn that my purchase utilized if I remember correctly at least UNF, UNC, BA, BSC, BSF, Whitworth and Metric designated threadings or measurements! In spite of, or perhaps perversely because of, my having overcome the challenge of dealing with all those threads and putting together a working motorcycle in spite of all that, I was daft enough to buy a 441 Victor and go through a similar process again! I guess I'm a masochist when it comes to Brit Bikes as I actually enjoyed the whole cursed exercise.

[PDA]

Quite right BG. We should also go back to pounds, shillings and pence to generate genuine mental flexibility. I'd like to see what the average programmer wopuld make of that for spread sheets. I already know that they can't handle 24 hrs, 60 minutes, 60 seconds for timing systems (I do handicap results systems for sailboat racing).

[Halfwitt]

MJ is a metric threadform with a radiussed root. Standard M profile has a smaller radius. MJ is better in terms of fatigue for studs etc because the larger root radius effectively gives a lower stress concentration factor.

However, I think Billy Gunn will find only the Whitworth tap has a properly formed radius at its crest (thus producing an internal thread with a nice root radius).

Using Mr. Whitworth's nice thread to extol the virtues of the imperial system is not a worthwhile argument. If Whitworth were alive today, his thread would probably be conceived based on a metric system.

I've used both systems of units, and I find metric easier to deal with. The units make more sense.
i.e thermal conductivity (I only chose it because it illustrates the point well)
metric: Watts per metre per Kelvin (W/mK)
imperial: British Thermal Units per sqaure foot per hour per degree fahrenheit per inch (Btu/sq. ft/hr/F/in)

And I draw things half and twice scale; it never occurred to me not to. Why is that??

[Ray Bell]

If we want to get into complications, how about we discuss number drills?

[Billy Gunn]

Well done Desmo and Halfwit!

Mr. Sellers was the all American equivalent of Mr. Whitworth! It was his thread system that eventually became UNF and UNC via the AN format. If you look at the t.p.i for UNC and BSW the only divergence is 1/2" where one uses 12 t.p.i and the other 13 t.p.i. The Unified thread series was established around 1943 between USA, Canada, and Britain in an attempt to standardize threads for wartime equipment, remember that British planes were being built in Canada (the Lancaster bomber for one), and many spares for planes like the Mustang were 'country of origin' related rather than type related! (i.e. the Rolls Royce Merlin engine used in the Spitfire was not exchangable with the Packard 'built-under-licence from Rolls' Merlin as fitted in the Mustang)

The UNJ and M(etric)J form threads were introduced by the aero industry to replicate the Whitworth BSW form thread where the root radius is a significant advantage in mechanical strength and fatigue improvement (by NOT promoting stress raisers at a critical point in the thread form)

Just as an aside; I know that at least one F1 engine has used (and probably still does use!) Whitworth BSW threads for the main bearing retainers precisely for this reason. It was designed with a Metric thread form main bearing/lower crankcase retainer but after block cracking caused by the stress raisers of the sharp angled Metric thread was changed to a Whitworth form and the problem went away!!

Ray - my research into Pounds, Shillings and Pence has revealed that it allowed the British to divide One pound evenly between 3 children! A feature that would have been useful with the Dollar (US, Oz, or Kiwi) I think it worked out at 6 Shillings and 8 pence, 2/3rds being 13 Shillings and 4 pence. Any Brits out there to confirm this??

DangerMouse ~ You are right on there, good buddy! The thought of some of the grads coming out of University these days getting their hands on life or death decisions is frightening. I heard a tale recently of an electronics grad (with honours!) at a placement interview not knowing what a resistor was!
I do know that there are some good ones out there, and that I should not denigrate all youngsters, but it is awfully tempting at times.

[DEVO]

I agree that metric makes everything easier and so does everybody else in the world, the problem comes during implementation. While metric makes calculations and design very easy the granularity of precision is not there (slowly but surely getting there). The reason that I'm stating this is because I read an article about the building of the Boeing 777. They couldn't build the thing using the metric system because the tools needed to build the plane to the tolerances that the engineers wanted were not there. So they went with the imperial system because the tools existed there. The standard meter length has been changed at least 2 (possibly more) times. The first definition of a meter was 1/??? the distance between the pole and the equator. Not very accurate. The second being the amount of distance some frequency of light travels or the length of the frequency of some stable element (can't remember). I don't know the details but you can see why the tools for metric measurements have had a tougher time of catching up.

[kartpete]

Hart engines up until the 99 season used predominantly imperial UNC/UNF fixings. I was told at the time that part of the reason was that the imperial threadforms were better suited for certain applications, for example standard metric coarse was not actually coarse enough for the block studs, as the slightly relatively coarser UNC was more resistant to stripping the threads in the block when the heads were torqued down.

[turin]

Hey Devo!
And what is the origin of the metric system. One foot? not very accurate as well.
At the end the whole thing is about some convention. If from the very begining everybody had used the same system, we would be talking about the same measure, and not doing the mental process to convert from one system to the other. Like the temperature. Or the Megabytes, or kyloBits. Some people count them like factors of 1024, other does like factors of 1000. ( 1 Mb=1024 Kb or 1000 Kb ??? ). At least we use the same scale of time everywhere.:-)
Ah... the tyre pressure is in psi. Not metric once again.

Turin

[Marco94]

I have read some of the comments here and am shocked by the lack of Metricists (for lack of a more silly word).

Now what really sucks is a system designed around the available digits of your average (i.e. 10 digited) knucklehead!

Billy, what do you mean by this?

The imperial system on the other hand (!) has an expansive role in the development of mathmatical thinking for your Junior school kids - this is a proven fact. Children taught the Imperial measurement system grasp Octel, and Hexadecimal far easier than those who have been taught the metric system.

I fail to see why this would be true. Beside that, the way I read it you are mixing up things. As far as I know, the Imperial system also uses decimal (base 10) notation for numbers. I fail to see the difference with octal (base 8), hexadecimal (base 16) or binary (base 2) notation.

If metric is so brilliant why don't computors use it?

It is very convinient for CPU manufacturers to build their circuits using a binary implementation of the decimal notation. From what I remember, in the very early days of computers some people tried decimal circuits, and octal circuits.

Absolutely spot on BG. Ask any kid today to add up and they are flummoxed, all the old biddies can do complex calculations in their head.

BG, DM, you are both right in complaining that people are "********" when it comes to hand calculations. Hell, I consider myself a dog in that area. But that is not due to Imperial/Metric. My father was taught Metric, as was I. However, he has probably never used an electronic calculator until the end of the 1970's. I have and therefor I never had the training during an early age. Of course I know how to do it, I am just not extremely fluent at it.

Calculating skills are indepent of the Imperial or Metric system. These days the Japanese are generally considered the champs of hand calculations, because they still get taught using a counting frame.

The British Code breakers in WWII were ordinary people off the street not mathematicians; The guy that devised the electronic programmable ALU for the worlds first electronic programmable computer (to break the said codes) was a uneducated post boy!

I wouldn't call Alan Turing "an ordinary person of the street," he was a brilliant mathematician as were his collegues at Bletchley Park, see these Alan Turing pages. As for the uneducated post boy, there have been more. Albert Einstein was a clerck when he first developed his Theory of Relativity. Talent and education are independent, they only complement each other.

The true story si just a case of plain stupidity. The sum BTW is expressed in base 10, without reference to Imperial or Metric. ;-)

In the end it comes down to what is more convinient for a particular application. When using money I like the consistency of decimal notation. I was horiffied to learn the 2/3rd of 6 Shillings, 8 pence is 13 Shillings, 4 pence. To me it sounds like it's getting more when dividing. No wonder the Euro is doing bad. On the other end using Whitworth thread as more appropriate for the engine BG mentioned.

Marco.

[Halfwitt]

6 shillings and eightpence is the legendary "Third of a Pound" (old pound) as mentioned previously. Not sure how much use that was.

13 shillings and fourpence is twice that, and not two-thirds of it.

[Peter]

WO Bentley, designer of those very British, le Mans winning vintage cars, designed the cars using metric measurements. The construction used BSF and Whitworth threads because that was what was readily available, but the main chassis measurements are all metric.

He believed that metric was the way to go even in the days when everything else was "Imperial", so there is nothing really new, is there?

Hexadecimal - Ah that will be pounds and ounces then!

I think I have finally realised why F1 cars all have to have 10 cylinder engines! It is Euro-metrication gone mad!

[Peter]

Originally posted by Halfwitt
6 shillings and eightpence is the legendary "Third of a Pound" (old pound) as mentioned previously. Not sure how much use that was.

13 shillings and fourpence is twice that, and not two-thirds of it.

Why call it an "old pound"? - it is still the same thing!

But there was also the famous "three and fourpence" or one sixth of a pound.

The great thing was the flexibility: with 20s in £1 and 12d in 1s you could get half, third, quarter, fifth and sixth of a pound. Conage was more fun too: 1d, 3d, 6d, 1s, 2s, 2/6 = half a crown (2s 6d = one eigth of a pound)

Now the Guinnea was a much more bizarre value (£1 1s)

There is no point endlessly trying to metricate everything until we can do the same with that universal problem: time.

Fortunately, kids still have to deal with the 12 hour clock and 24 hours in a day, 7 day weeks, etc.

There have always been inconsistencies too: US engine capacities are imperial (cubic inches) whilst British ones have always been metric (litres or CCs) whilst the $ has been metric all along.

[MrAerodynamicist]

Of course there are two metric systems which I will defend to my death - mph and pints (of beer)

[Halfwitt]

Originally posted by Peter


Why call it an "old pound"? - it is still the same thing!

There is no point endlessly trying to metricate everything until we can do the same with that universal problem: time.

An old pound was 240 pence, and six shillings and eightpence went into it three times exactly. The new pound still contains 20 shillings, but of five pence each, and not 12 as previously. The strange bit was the period when an old sixpence was still legal tender, and worth two-and-a-half new pence

Now the interesting bit...
The ancient Egyptians used their digits to count almost everything in tens. They used a solar calendar with 36 ten-day weeks or twelve months of 30 days plus five dog days and, later on, a leap day at the end of the year. They divided daylight into ten hours and then added another two hours for twilight and twelve hours for night, which varied with the seasons. Many Egyptian ideas were adopted by the Greeks and then the Romans. Instead of dividing the day in a decimal way, Greek astronomers used 24 equal hours then divided these in the Babylonian sexagesimal way into 60 firsts and 60 seconds, which they could not measure very accurately.

This system was used in mechanical clocks until the French Revolution
when DECIMAL CALENDARS AND CLOCKS WERE ADOPTED, then abandoned when Bonaparte reverted to Roman Catholicism, shortly before invading Rome.

Decimal time divides days into a thousand tims (1 tim = 1.44 mins).
These can be subdivided in the usual fashion into millitims, microtims...

The source for this was The Decimal Time Society (!!!)

http://www.decimalti...co.uk/main.html

[regenmeister]

I think no high-tech constructor uses imperial system when drawing.

Old Enlish Monetary system:
Two Farthings = One Ha´penny
Two Ha´pennies = One Penny
Three Pennies = A thrupenny Bit
Two Thrupences = A Sixpence
Two Sixpences = One Shilling, or Bob
Two Bob = A Florin
One Florin and One Sixpence = Half a Crown
Four Half Crownes = Ten Bob Note
Two Ten Bob Notes = One Pound(or 240 pennies)
One Pound and One Shilling = One Guinea

The British resisted decimalized currency for a long yime because they thought it was too complicated.


Metric vs. Imperial (Round One)

Metric:
If you have a floor that is 10*10 metres and is covered with 1 centimetre of water, how much water is that in litres?
Easy:100*100*0,1 = 1000 litres.

Imperial:
If you have a floor that is 10*10 yards and is covered with 1 inch of water, how much water is that in gallons??

Could someone answer me that in 3 seconds please?

I think metric won on T.K.O.

[gray_cat]

Originally posted by Billy Gunn
If metric is so brilliant why don't computors use it??

So what do computers (or computors if you wish) use, Billy ? Pounds and inches ?

Doesn't seem you know anything about computers and electronics.

Binay system of numbers is not metric nor imperial, it has nothing to with measurement at all - it is system of numbers.

Binary numbers 0 and 1 are representing states of electronic gate or valve. Since the most efficient and flexible valves(gates) operate two states - low and high - they are 'binary' by nature. Octal and hex numbers are used for convenience in presentation only - compare 1F0 (hex), 496 (dec), 720 (oct) or 111110000 (bin).

[Timm]

Grampa Simpson;- "The Metric system is the tool of the devil"

Jeez, roll on the F1 season and its fortnightly supply of more interesting technical topics!

I'm an aerospace engineer educated entirely in metric and curse the imperial system! When is 10-32 not 10/32, etc., etc. I cannot picture a measurement until I've converted it to metric.

I totally accept that the imperial systems longevity in the Aero industry is due to (a) The effect of the superb R&D done by US and UK aero companies pre-metrification which is still relied upon (b) The dominance of Boeing & the US military aerospace companies

Keith Duckworth himself said in an early '90's interview for 'Car Design & Technology' magazine that the engineering industry had "the perfect thread" but discarded it. It was, of course, the Whitworth. A few years ago when working for a company 'reverse engineering' US auto parts that dated from the '30's onwards, I tryied to get a supply of Whitworth bolts and failed miserably. Our supplier said there was no demand for them and that I should use UNC items because "....they're way better". Mmm, Keith Duckworth or a fastener salesman, who'd you side with?

Didn't the structural failure of the Russian Concordski have something to do with fastener conversion?

p.s Does anyone want to pull the pin on the fluid connection topic??

[Ray Bell]

I'd like to know more about number drills...

[Timm]

Billy Gunn, I agree with your comment concerning the ability of graduates.

I graduated with an Aero degree in '96 after taking 6 years to get my degree, during which time I'd been on placement and had enjoyed two years in a more practical course where I learnt about measurement & manufacturing.

A year 2000 graduate of a UK University (Aerospace) stunned me recently by complaining about a job interview he'd recently had. Apparently, the interviewer had the temerity to ask this guy to measure the diameter of a cable using a miocrometer. The result........."but I didn't do Micrometers in college". Unbelievable!

[palmas]

Originally posted by regenmeister



Metric vs. Imperial (Round One)

Metric:
If you have a floor that is 10*10 metres and is covered with 1 centimetre of water, how much water is that in litres?
Easy:100*100*0,1 = 1000 litres.

Imperial:
If you have a floor that is 10*10 yards and is covered with 1 inch of water, how much water is that in gallons??

Could someone answer me that in 3 seconds please?

I think metric won on T.K.O. [/B]

Easy: 10*36*10*36 = 129600 cubic inches

[Bjorn]

Hmm... make that 10*10 feet since a yard is pretty much the same as a metre

Is a cubic inch = gallon? Because the answer was supposed to be in gallons...

[Ray Bell]

Gallons in cubic feet is one of the tricky ones... I think it's 6.4, but some say it's 6.5, and that's imperial gallons... US are smaller, but their feet the same... still smelly.

[Ray Bell]

Something that's not been mentioned in this discussion is links...

[Halfwitt]

Don't start that one. Imperial is nasty, but proper old imperial dealing with bigger units is very nasty.

[f91jsw]

Just want to clarify some things about the misconception that imperial units would be somehow more accurate than metric, and about the definition of the meter.

The meter was originally defined as 1/10,000,000 of the distance from the north pole to equator. Very quickly (in 1799), the definition changed to be the length of a certain platinum bar in Paris.

In 1875, USA adopted one of 30 prototype platinum standard meters, derived from the one in Paris, as the nation's official fundamental standard. The foot, yard, inch etc. were from then on related to the standard meter. So, saying that imperial units are more accurate than metric doesn't make much sense, since the two systems have been directly connected for more than a century (with the imperial system defined by the metric).

In 1889, a new standard meter and new secondary prototypes were made in Paris. This time made of a platinum-iridium alloy.

In 1960, a new definition of the meter was adopted, as 1,659,763.73 wavelengths of a certain energy transition in a certain krypton isotope.

In 1983 we got the definition used today: the meter is the distance traveled by light during 1/299,792,458 of a second. This ties the meter to the definition of the second, because time can be measured more accurately than anything else in physics.

[palmas]

Originally posted by Bjorn
Hmm... make that 10*10 feet since a yard is pretty much the same as a metre

Is a cubic inch = gallon? Because the answer was supposed to be in gallons...

A yard is 3 feet 3*12*25.4 = 914.4mm

don't get me wrong: I only use metric, and only know imperial to be able to say evil things about it!

:lol:

[Ray Bell]

Right, f91etc... I'll get the stopwatch, you grab the tapemeasure, who's turning on the light?

[desmo]

What's that in cubits? I got the hourglass ready...

[Ray Bell]

Sorry, des, the standard for the cubit was left on the Ark, and Nimrod and the boys caused such havoc that everyone forgot where they beached that...

They were going to go back for it, too, but some venison was cooking and, well, you know how it is!