Back to Imperial

So, back in the sixties when Ingineering was supposed to change to metric in GB., it was hard to do a full change over so one had to become bi-sexual for not only lengths but later in money. Despite working in metric, I still did (and do) go through mental gymnastics converting back or forwards to get a "Feel" for a tangible size. Since dressmaking sizes are taught to the youfs, 25cm means s*d all to me but 250mm is about 10".

Then skipping on a few decades and job changes we go into the electronic industry and find that although the PCB panels are laid out to metric dimensions, the pre forms for things like transistors and ICs are IMPERIAL spacing thanks to Uncle Sams refusal to go metric. No problem for one offs but for thousands? and then having press tools made to punch hundreds of holes through the laminate to mount the components. Given that all measurements should be generated from an X-Y datum point, the use of sub datums to the individual component become more important, so dual dimensioning. This of course for wire ended components, pre Surface mounts. Must have been difficult for the Australians on Metric Day.

Regards Ian.

School science lessons were so much easier in metric, rather than buggering about with archaic rubbish like BTUs. One of the best events of recent years was dumping duodecimal money. Fart-hings, x 2 = one ha'penny, x 2 = one penny, x 3 =a threpenny Joey, x 2 = a tanner(6 pennies) x 2 = a Bob/ one shilling, x 2 = two Bob or x 2 1/2 = a half crown. Then 10 Bob notes × 2 = £1note x5 = £5note, which we still have.

What a load of old crap dating back donkeys years. Nothing wrong about the age, just the awkwardness of calculations. Same goes for weights and dimensions. For those who don't know, old penny noted as a 'd' which is an abbreviation of denarius being a Roman coin. The shilling likewise, was an 's' Roman solidus.

We just need to stop Networkrail from continuing to use 'Chains'. No doubt there are many more examples of the old medieval system.

I am happy to use whatever I am confronted with, all my machines having Imperial leadscrews and dials to match. Model engineering metal stock much easier to obtain in Imperial sizes and use metric screws or Imperial, depending upon what their use is. Tools/ accessories for mills/lathe etc use metric easily obtainable locally. Use conventional Imperial screws on models. Loco and clock drawings all Imperial, doesn't matter too much to me. Harold Hall's books and grinding jig drawings in metric with metric threads. Fine by me.

John

I was only taught imperial at school so had to convert to metric on the job so to speak. I have never used cm and we never used them at work so I don't understand why cm are taught in schools. For the sort of things we built at work, working to 1 decimal place in millimeters seemed a much better idea than working to 2 decimal places in cm.

I like to think of myself as "linearly ambidextrous", but there is no way I could go back to feet and inches now.

Peter

The problem with metric is that third digit on the DRO or digi-caliper.

The hours I spend setting it to perfection on the cross slide only to see it blasted out of existence the moment tool tip meets steel.

Come back thou, all is forgiven

France uses the cm a lot - imagine the surprise on the glazier's face when I asked for some picture glass 450 x 350 x 2.5 (45cm x 35cm x 2.5cm !!!)

Ignore the third digit

Tony

When woodworking I tend to go straight to imperial when measuring and marking out. Having said that if a plan or something that is in metric I can also use that equally as well.

Having worked for a Swiss firm for many years the there never was a split of metric measure, it was always meters/millimeters. 1.155 as an example. Not once in 37 years did i see cm used to give measure.

Pedant alert!

Alas not!, the beer glass Crown was an Excise Mark, confirming the capacity of the glass for both customer and the Government. CE is a conformance mark: sellers add it to assert the item meets relevant EU standards, which are usually safety related.

Provided it's honest, CE assures the customer the item is safe to a standard acceptable in all European member states. Governments don't care much about them. In sharp contrast, the crown mark was only valid in the UK, and the Crown cared very much! It was a reminder to the trade that alcohol was taxed. Customs and Excise made rigorous checks and had more extensive powers of entry than the police and inland revenue. Avoiding excise duty was a serious criminal offence, and the government dropped like a bomb on offenders. Being an offence against the crown, expect the maximum penalty!

Crown and CE Marks have nothing to do with quality. The beer in a Crown glass was often a bit 'off' as I remember, but once sold, then tax is payable. Likewise, CE marks can be stamped on rubbish, and there's no come-back as long as it's safe. And even if the item is hazardous no action will be taken unless Trading Standards give it priority, which is unlikely because they've all been slashed back since the 1970's.

These days the crown mark is unnecessary on glasses because pumps are calibrated for tax purposes. Putting Crown Marks on glasses now has no meaning other than nostalgia. About as daft as my local herbalist, who once claimed their shop to be a 'Nuclear Free Zone'. Yeah right!

Dave

Ale hand pumps are not measured delivery and most or the lager trees deliver as long as the tap is open. A hand pump might deliver half a pint per stroke on a good day but they are rare, if the bar staff are a bit green then a top up is often required. Electric pumps are rare in this part of the world.

Mike

At one time, measured pumps were introduced to serve beer into oversize glasses. ( exactly 1/2 pint at a time ) These proved to be unpopular with the licensees, as they couldn't make anything on the head. These days, at least around here, it's either hand pumps or free-flow into pint glasses. That way you get between one and two fluid ounces short of a pint and the pub makes more money. Probably doesn't apply down South where they like beer without a head.

Measured pumps are reliant on the rest of the system being up to scratch. As soon as the cellar/barrel/delivery line temperature changes, or the pipe cleaning is a day late, or the button isn't cleaned with the correct chemical, or the clouds across the moon are too thick, the measured quantity changes. So you end up with a row of glasses with varying quantities that you hope the customer will accept being poured into their glass. Wastage goes up through the roof, profit drops through the floor and the scrap pile gains another heap of expensive junk.

Here in the south, I won't accept a southern beer that's been forced through a sparkler to create a head that isn't appropriate. A northern beer also shouldn't need the sparkler to create a head; it should be a natural part of pouring the pint.

When I used to work offshore, practises were still dominated by American custom so most things were imperial. We had to measure the drill pipe and sum all the individual lengths up. To make it easier they decimalsed the feet, so a foot had 10 (long) inches in it. We were issued with specially made tape measures!

Hi, talking of pints and short measures of beer, back in the latter part of the 70's, slightly larger capacity straight pint glasses became more common which had a white line near the top to show a full point measure, which I guess allowed a pint to be drawn with a head and would be at least a full pint after any head had settled down. One night I was in a pub with some friends and we were at the bar ready to order, there was a guy who had just been served a pint and it was below the top of the glass and he asked why the glass wasn't full. Another guy standing just the other side of him pointed and said about the white line shows the full pint, at which the first guy turned to him and in a rather grumpy agitated voice "I was asking the bleeping barman not you" we all looked at each other with raised eyebrows and I think someone in our group said quietly "that shut him up"

Regards Nick.

I spent a few years in my youth working behind a bar where the glasses were the oversize straight type with a line but they didn't have the crown or the words "Pint to line" or whatever the wording was since they were rejects (read cheap). We just filled them so the beer was over the line and with a head on top. Then they introduced measured half pints for Guinness. That, as I am sure you all know, takes an age to settle but we started to get complaints to the point where some of the bar staff had a pre-poured half under the counter to top it up. Where I worked has been demolished now but it was a venue where the Beatles played a number of times in the sixties.

Martin C

.... not to mention spelling

+1

You think that's bad; whenever I try to work out anything using Pi I have to give up after just a few hundred decimal places.

I feel your pain. Unlike Gerber, AutoCAD defines an arc by angles rather than by end points, Stray from the cardinals and nothing quite fits

Is that true? In my youth I failed to get on with AutoCAD because it had so many features that I didn't have time to explore, but many people rated AutoCAD highly. I found it difficult to navigate. Now I happily use QCAD for all 2D plans. Although simpler than AutoCAD, QCAD has ten different ways of drawing arcs only two of which require angles. I'm surprised AutoCAD doesn't do much the same: possibly other arc options are hidden behind a sub-menu?

I remember reading an article about AutoCAD in MEW or ME where the author reported lines not joining. I wondered if he was driving AutoCAD wrong, either by not selecting the right tool, or not setting the appropriate snaps. The latter are important and not always obvious.

Dave