Scale drawing - structure conversion

Model Railroader Layouts and layout building
1

I want to convert to a scale drawing a footprint of 10" x 13" to HO scale using 1/2" and 9/16’ scale.

Where can i go to learn conversion?

Thanks.

2

Your question is unclear - where do the 1/2" and 9/16" scales enter the equation? If the stated footprint is 10"x13" (in “real” inches), simply use your HO scale rule to measure those dimensions. Ten real inches is about 72’6" in HO scale, while 13" scales out to roughly 94’.

If you need to re-draw that in 1/2"-to-the-foot, the 10" dimension becomes 36.25" (.5" x 72.5), while the 13" side will be 47" (.5" x 94).

Wayne

3

Thanks. Hard to conceptualize this stuff.

Sorry. When i look at track plans some are 1/2" = 1’, 12’’ grid or 3/8" = 1’, 12’’ grid, etc.

So if i draw a layout using 9/16’’ squares or 3/4" squares the size of the building will be different for each size.

Not an artist, draftsman, or architect so its been a little difficult for me to draw a track plan.

4

Ah! Totally different from what I said, which would convert an HO scale foot into a real 1/2". [:O]

Not being one who draws trackplans as anything more than a sketch, I’m probably not much help. I can tell you, though, that accurately depicting the width of a track or turnout, and the clearance required around it is more difficult to do on a drawing and is at least as important as the size of structures.

My procedure is to make a simple sketch of a track layout, then using one turnout and a length of flex track, try to duplicate the plan, by turns, in place on the layout. I then alter the buildings to fit the space left-over. [swg]

Wayne

5

Converting between full size and scale size (or between two different scales) is simply a case of division and multiplication, plus a little basic calculations with fractions.

Example: you have something which is 10" long in your drawing, and it is drawn in a scale where 1/2" (=0.5 inch) equals 1 foot in reality.

You want to draw this length in a scale where 1 foot in reality equals 9/16" (= 0.5625 inches/foot).

Two possible different ways to go:

  1. Convert to original size, then back to new scale size:

10 inches / (0.5 inches/foot) = 20 feet
20 feet * 0.5625 inches/foot = 11.25" - or put another way 11 1/4"

Or 2) Find the ratio between the scales once and for all, and multiply all sizes with this

Ratio new scale/old scale = (0.5625 inches/foot) / (0.5 inches/foot) = 1.125

Measure in old scale: 10"
Measure in new scale: 10" * 1.125 = 11.25" (or 11 1/4")

Smile,
Stein

6

Thanks for the help.