Sunday, June 10, 2012

Death to the imperial forces

PlasticWhat is it with railway modelling and the metric system ?

Why is plasticard still sold by the thou ?

I have no idea what a thou is but I do understand millimetres and decimals of these. It's really not difficult and every kid who has been in a school since the 1970's understand this. Metric measurements are easy with lots of tens to calculate. Despite this, you can't find 1.5mm thick plastic sheet, it has to be 60 thou.

Another bone of contention; America, it is the 21st Century and you lot still can't do metric either. Look at this lovely 1/2" tube, or 12.7mm diameter. Just do 13mm, or better still 14 which was what I wanted in the first place !

While using the plastic, I found this handy on-line converter from thou to mm.


Colin 't Hart said...

What about all the various scale definitions?

HO (USA) = 3.5mm to the foot
O (UK) = 7mm to the foot
1 (UK) = 10mm to the foot
SM32, SM45 = 16mm to the foot representing 2- and 3-foot gauge prototypes respectively

And there are many more...

Jim Musser said...

Phil -

Don't hold your breath as I doubt I'll ever see the metric system here in America during my lifetime. When I was in grade school they were teaching it universally under the premise that we would be changing over within a few years entirely. That was back in the 70's. I'm not sure what happened but its gone for good. I suspect that it all boils down to is that in adopting it we would be tacitly admitting that Europe was right and we were wrong. If Europe didn't include the despised French we might not be having this conversation. The whole thing makes my life a nightmare - I'm a builder so all day long I deal with fractions of inches - 1/16, 1/32, 3/32, 3/16...... etc. And then I have to convert back since many of my tools are German made, so only have metric scales on them. So finally, just as my head is about to explode I finish work and come home only to deal with mils, not millimeters, but mils or decimal imperial amounts - .040, .060. ...etc., which I have to many times convert back to fractional inch amounts since scale wood and some scale plastic come that way.

Phil Parker said...

Wow - You wonder if it wouldn't be easier to invent your own measuring system. Cubits anyone ?

Zabdiel said...

mm to the foot does make sense if you're building models things from before the metric system. Thou are thousandth of an inch, but I agre they're a stupid unit!

Pennine MC said...

Talk of metrication dates back to my schooldays, to be honest I can work in either and I know I'm not unique. I do tend though to use whichever suits the situation best - millimetres if it's a component on a model, feet and inches if it's a carpet :-)

Never had a great problem with 'thous', I know that 40 thou = 1mm, near as makes no difference, and work from that basis.