I think a brief discussion of "English vs. Metric" system of measurement and the trade-offs for each as it is pertains to ship modelers and other modelers in general is appropriate to this forum.
(Dana L. McCalip)

Let us be certain to impress on the list members who are new to modeling that they should pick either metric or English measurements for a project.

If there is anything out there which can screw up an already mysterious (as seen by the eyes of a newcomer to ship modeling) undertaking, it is trying to wend back and forth between metric and English. With the exception of Dana's observation concerning the availability of ready-made parts, it really doesn't matter which you use. But only use one method per project!!! Beware, beginner, thou hast been warned!

This comment was and is directed to the beginning modeler. As the beginner develops his or her skills the ability to rapidly flip-flop between the two measurement systems will be attained. I would be most surprised if you experienced modelers could not interchange at will. Let us all remember that in addition to helping one another, our mission here (as I see it) is to help train the novice.
{Mickey Martelle}

I personally think all you guys (and gals if there are any) are making a mountain out of a molehill regarding metrics and English. Both are units of measurement. There may be a slight difference between a metric part and English, but it is very close in the scales we deal in. I put both English inches and millimeter units on my plans, so the US guys can use inches, and the overseas guys can use millimeters. Its more of a familiarity with one system vs. the other.

With models, what I have seen is equivalents that are really not equivalent. I am currently working on a project done in Italy, and the Italian firm gives basically millimeters. However, they have also given equivalents in inches. For example, they wanted certain parts cut from 1mm thick wood. They said this is 3/64" in inches. Well, that's not exactly true because 3/64" is 1.19 millimeters. But does it really make a difference? Use 1mm wood cut in Europe or 3/64" cut in the US and at a small scale the difference is hardly noticeable. Am I making myself clear? I f not I would like to hear more from those interested, and be more specific. The last few messages I read were too general. This one I am responding to is an example. "Stick to one system. Why? I often use inches and millimeters on a project. Sometimes I find it easier to divide things or measure things in millimeters than inches. I relate to full scale sizes better in inches, but I am talking about the process of model building. I think everyone who is involved in technical stuff like model building should be able to work and interchange either system. If you can't you are just not doing your homework.
{Ben Langford}

I have been following the English/Metric scale discussion with interest. All of the contributors have had valuable things to say, and I have only two small things to add.
  1. I have a 6" steel rule from Model Expo with both English and Metric scales. The first 5 cm of the Metric scale are graduated in 1/2 mm increments, which is more than small enough for most woodworking purposes, since I always cut a little long and then sand or file to fit. I do not know if it is still available.
  2. When working in 1/2", 1/4" or 1/8" scale, I use metric ruler divisions to approximate full size English units. While this sounds a little screwy, it works quite well. This is because of the close approximation between the scale (1:24 for instance) and the ratio of English to metric.
For example, if a cap rail is 4" wide, full size, it will be 4/48" or 1/12" in 1/4" (1:48) scale. This is a measurement which does not appear on any ruler.

However, at the same scale, 1mm is almost exactly equal to 2" ( .8912" precisely), so I measure 2 mm and I have my 4" actual dimension. I do not do this when building in 3/16" or 3/8" scales, since the divisions on the ruler match full sized actual dimensions. For small details or ropework I use calipers, as has been suggested by others.
{Dan Pariser}

I probably am talking too much, but to "train the novice" is not to say avoid something. If the novice does not deal with metrics and English, how the hell will they ever learn anything.

Let's tell them how to deal with the subject, not to avoid it. Most novices are model builder novices, but they are not idiots. Some are probably as old as we are and with a lot more technical skills. Do not assume that a novice model builder is some dumb s-o-b kid.
{Ben Langford}

The ONLY time that using "English" or "Metric" units matters is when you're converting the ACTUAL dimentions to the scale dimensions - then one set of units or another may be more convenient, depending on the units of the original dimensions and the scale conversion; 1 meter is easier to convert to 1:50 using decimal and 3 feet is easier to convert at 1:48.

If you're MEASURING from a drawing, it doesn't matter - a compass (with NO units / dimensions) will work just as well!
{John O. Kopf}

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