Elevator Lift

I prefer metric. I loathe and detest fractions. My sense of scale is 100mm is approx. 4in. So 300mm = 1ft and so on all dependent on a little head math. For small things around 5000mm (approx 200in) I think in mm any way. Larger than that I think in feet or miles. Most of the projects I work on are in the largish size for machining in the 500 to 5000mm size. I do not think in centimeters or anything else. MM, inches, feet or miles. Nothing else. I wish we would go metric so bad. I usually end up making multiple reference drawings where I have to convert to inch. Metric is easier. The running joke is about table tilt/rotations... metric or inch degrees.

:)

I much prefer metric... and this from a guy that was born and raised in an imperial system. No fractions to deal with and you're dealing with a--for the most part--metricated world. Units, equations, calculations... everything is just easier with metric.

On the design side, I equate working in inch only to having a 20-drawer toolbox and opting to only work from 2 drawers; it really limits design of machines. Not to mention, most of your 'design around' components are from Japan, Germany, UK, etc., so no need to convert.

And I'll go on to say that... most of our legacy stuff is imperial, all of our newer stuff is metric, and I played no small part in pushing that changeover home, painful as it was for some.

Same was true at a number of plastic-injection mold shops I worked at and the trend--anecdotal as my observations may be--seems to be a move 'away' from imperial.

I WOULD be interested in seeing sales numbers from companies like DME and others who offer both inch and metric componentry to see what their trends show. That might be interesting.

On the other end of the spectrum, you have Ford, GM, Caterpillar and others who've moved in that directions as well... which in turn forced their suppliers to move in that direction. So it's a slow creep of 'metrification' but when I look at the global marketplace as a designer, again, I want the most options available to me and I get that with metric.

CAD is not very good with the fractions that occur with imperial units. The workmen will be using tapes and rules that are marked with 1/2, 1/4, 1/8, 1/16, 1/32 and 1/64 of an inch. Back in the days of hand drawing these were easily put on a drawing. CAD likes decimal values 24.0625" is not as friendly to a workman measuring a part with a steel tape as 24 1/16". The same dimension measure with a metric steel tape would be read as 611mm. Much more convenient.

Lawrie,

I agree. Even worse is when you consider the number of significant figures in a drawing. If you have to use decimals it becomes difficult to convey 24.0625" when you are forced to display 24.1" on the drawing.

I worked for a few years in a production shop and had a great relationship with the manufacturing floor. We worked together to develop a drawing "standard" that worked best for them. The best option in that case was showing actual fractions on the drawings since that is what they were reading from their tools.

It took a little extra work in the design stage to make sure there were not going to be some errors from the stacking of fractions, and rounding up/down, but these products were not precision assemblies. I actually have one uploaded here:

Grabcad model

Genetic Research Rack

While looking through some old data, I came across the first batch of CAD models I made. A 700 piece assembly is not very large today, but back in 1999 it was pretty big, and daunting to a self taught SolidWorks user.

If I were in a similar situation today, I'd bring in some metric tapes from home which measure in millimeters. Then let the shop floor decide if they wanted to deal with fractional tapes, or mm tapes. I'm pretty sure there would be a few who would cling to their fractional tapes since they are used to them. But mm tapes are so much more convenient.

Most of the tapes I have at home show dual units. It is like the best of both worlds since you can make use of whichever scale has a marking in just the right spot :)