Converting ship scales to architechs ruler

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Can someone help with this. I have a variety of scale ships, but I am not that familiar with the arcitechs ruler. I just bought one for scratch building.
 
If you’re working in imperial (US) measurements and the model you have is also US then it’s pretty easy. 1:1 scale is obvious as 1” equals 1” or 1’ equals 1’. 1:12 scale would be 1” = 1’-0” (12 inches in a foot); 1:24 scale is 1/2” = ” 1’-0” (24 half inches in a foot)
Most museum models are 1:48 scale or 1/4”=1’-0” (48 quarter inches in a foot)
1:96 scale is 1/8” = 1’-0” as there are 96 1/8 inch sections in a foot.
Hope that makes sense…
 
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If I understand your question correctly, then the measurement on the model will be 1/200th of the measurement on the real article. Or are you trying to convert from one scale to another? In that case, it would be the measurement on the model times the times 200 (to get to 1:1 scale), then multiply by the scale to which you are converting (e.g., 1/48, 1/35, etc.). If I misunderstood your question, then I apologize.
 
Like OlivierF says, in the US, an architect's scale has scales of 1 foot equals 3/32", 1/8", 3/16", 1/4", 3/8",1/2", 3/4", 1", 1-1/2", and 3". These translate to 1:128, 1:96, 1:64, 1:48, 1:32, 1:24, 1:16, 1:12, 1:8, and 1:4. An US engineer's scale has scales of 10, 20, 30, 40, 50, and 60 feet to an inch. These translate to scales of 1:120, 1:240, 1:360, 1:480, 1:600, and 1:720. If you're working in any other scale, go metric. I remember in the 70's the US was going to go metric. I don't know what happened but the only use of metric currently is for alcoholic beverages. Of course, you do need metric wrenches to work on any recent car or bicycle. Fair winds!
 
I prefer metric in everyday use and wish we would convert to it in the US, but for ship models of the 16th-19th centuries all contemporary information is imperial and I find it much easier to scale things using the same measurement system. In the end the length or width will be the same whether it is called 1 inch or 25.4mm
Allan
 
As a collateral duty to my job, I was involved with a committee writing international standards for pipe fittings, flanges, etc. There is a host of ASTM standards already written for these so a big part of this project was “metrification” of American catalog listings. It turned out to be much more difficult than one might imagine.

There are “hard conversations” and “soft conversations.” Hard conversations involve a complete redesign for the components in question.

In theory, soft conversions are simple; all that’s involved is converting fractional US dimensions to their metric equivalent. For example 100 mm pipe has the same dimensions as 4in pipe. But then the actual diameter of 4in pipe is 4-1/2in not 4in. A catalog entry would list the nominal size as 100mm but the metric equivalent of the actual dimensions for American 4in pipe. Many European and Asian specifications that I have read specify these converted American pipe sizes.

But, what about flanges? American flanges are rated by size and pressure. eg. 4in 150 Lb (psi). First of all, How does one easily convert psi to an easily used ,equivalent metric pressure rating familiar to most American pipe fitters? Then what does one do about bolts? The holes in American flanges are based on sizes and strengths of Standard American nuts and bolts. A soft conversion of these is a different matter.

My point is that there are a huge number of American products governed by industry standards. This allows the user interchangeability regardless of the manufacturer. In turn, the manufacturers have invested in tooling to make these interchangeable products. To abruptly change these for the USA’s huge economy would have a huge economic impact with no gain.
Not just stubbornness but sound economic reasoning.

For model ship building, I am able to think in the various fractional scales. Not so, metric.

Roger
 
I bought this digital caliper/ruler because you can set a scale and then the ruler will adjust electronically to support it. I especially liked you can tell it to equally divide an area at scale (I was thinking of hull and deck planking ). I came with attachment for caliper, ruller and drawing uses. https://hozodesign.com/products/neoruler-premium-combo. It was a bit pricey though, but it beat doing the math

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EXAMPLE​
PREVIOUS
One foot 1´= 30,48cm
One inch 1´´= 2,54cm

Ship model has :Length 48" / Height 32" / Width 16" /Scale 5/32"= 1 ft. (1:76Scale)

Operations:

5/32”=0,15625
0,15625x2,54cm(one Inch)=0,396875cm

30,48cm(one foot
) /0,396875=76,8---scale 1/76
 
Thanks. But what about 1/200 etc. The other scales of ships?
Always think of it in terms of a ratio. 1/200 simply means that 1 unit of the scale is equivalent to 200 units of the real item Example: 1 inch (or 1cm) on that scale would represent 200 inches (or 200cm) in the real world. Those architect/drafting scales come in a pretty huge variety in both metric and imperial units, so you can pretty much always source one that's appropriate for the scale drawing you're working from. I used these things in my work over forty-five years ago, and believe it or not, you can still find them on sites like Amazon. You may even find them in some of your local stationary supply stores like Staples... those outfits always have a small selection of drafting and drawing tools.

As to metric versus imperial units, being a Canuck, I'm of the generation that grew up using imperial units, and then as a nation we switched to metric about fifty years ago. Sort of switched, and it was a painful process. In the building industry, windows and doors were still manufactured in imperial sizes, but listed in millimeters. Same for dimensional lumber, so a 2x4 (which we all know isn't actually 2 x 4 inches... actually 1.5 x 3.5 inches), then became listed as a 38x89. Again, just conversion of an imperial sized item into millimeters. But other things got hard converted... masonry items like bricks and concrete blocks. Great for anything new, but if you were doing repair or renovations/expansions on existing buildings, imagine having to adjust the mortar lines so the courses could line up. You can still spot some of those today. Studs were placed 400mm on center (close to 16"). Plywood sheets for a short time... a very short time... were 1.2 x 2.4 meters... which made them slightly narrower but also slightly longer than a 4'x8' sheet. Now, most items in the local hardware stores like Home Depot and Lowes list the items in imperial units again. Personally, my relationship with measurement systems is a mixed bag of nuts. When I drive, I think of kilometers of distance, and kilometers per hour of speed. But when I'm in my woodshop, my work is in inches and fractions of inches. I think of indoor and outdoor temperatures in degrees Celsius, but I bake in Fahrenheit. I buy food in kilos and liters, but again, cooking is done in ounces, cups, and teaspoons. I guess the only real life advantage is that when traveling in the US, I can readily convert back and forth between the two systems for temperatures, distances and speed. I know younger generations likely work almost entirely in metric, but for me, part of me always finds it easiest to revert to the system I grew up with.
 
I do not find useful the mechanical scaling instruments as scale rulers for example. When I have a scaled drawing of a ship , and I want to know what is length of this or that part for my own scaled build I do as follows. Let us say my scaled model to build is 1:90. This means that my model is 90 times smaller than original. First I must know what is a scale of a drawing I have. Let us say it is 1:384. I take a metric ruler and measure the part length in millimeters off this drawing. Let us say it is 12 mm on 1:384 scale drawing. I multiply 12 mm 384 times using my hand calculator. What I get is actual length of this part in millimeters. Then I divide this value by 90 which is my scale of ship I want to build. Result is a length of part for my build in millimeters. In this case 12 times 384 divided by 90 equals 51.2 millimeters. What can be simpler than this?
 
Hi
The most important thing
1/40 is GREATER than 1/60
1/60 is LESS than 1/40.
The bigger the number in the denominator, the SMALLER the scale

Sorry
I cannot translate the attached document

CAMBIO ESCALA.jpg
 
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