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Re: SI units..



Original poster: Steve Conner <steve@xxxxxxxxxxxx>


who write that something was built out of "lumber 5.08 x 10.16 cm" instead of "2x4's"

I've seen a lot of stuff like this as the UK gradually gets more and more metricated :-) I remember an advert for one piece of software that came on a "89mm" floppy disk. Which is just plain stupid, as you have to get out your calculator to figure out that it's a 3 1/2" disk. Another crazy thing I saw recently was architect's plans for a multi-storey building with all the dimensions in millimetres.

Probably the worst thing is printed circuit boards. These were traditionally done in grids that are sub-multiples of 0.1 inch: 1/10", 1/20", 1/40", 1/80", 1/160" etc. But most new component packages have metric pitches and when you mix the two types on one board (as you very often have to) the result is just a total pain in the ******

At least John Freau hasn't started selling 100 x 330mm spun toroids though. I don't know why, but I always end up building my Tesla coil equipment to inch dimensions. Having said that, my idea of precision engineering is "I think I'll drill a hole hereabouts" so you probably couldn't tell if it was meant to be metric or imperial in the first place.

Steve Conner
http://www.scopeboy.com/
"Give a man an inch, and he'll take 1609.344 metres"