What Is “Accuracy”


Avoiding the Placeholder Trap


When we say something has been modeled accurately, what exactly do we mean?  Does it mean that we’ve performed a careful survey of the bristling details on a specific locomotive, documented them on an excel spreadsheet, tracked down said details, and meticulously applied them?  Can we go back, compare our model against the list, confirm that each detail has been neatly applied, and say our model is accurate?   Often not.  This is what I call the placeholder approach.

Let’s say your subject is a weather worn geep with spark arrestors.   Model A sports the stock manufacturers paint scheme.   After a considerably long catalog search you track down the spark arrestor but it is a fairly rough metal casting.  The casting has the correct dimensions so you apply it.  All of the grab irons match up but, as is the case with many injected molded parts, are slightly oversize.

Model B doesn’t have the spark arrestor but has been masterfully weathered with what has to be a half dozen subtle layers.  You replace the factory grabs with thinner ones but, for the sake of argument, let’s say you installed five grabs instead of the prototypically accurate six.  Five accurately sized grabs on model B verses the theoretically correct six (albeit oversize ones) on model A.

Which model is more accurate?   Most would say model A because each part on the prototype is represented with a placeholder on the model.   I’d argue that model B is more accurate.

Accurate color and accurate cross sections create far more visual impact than simply saying each part has been represented by a placeholder. Accuracy means accurate weathering and cross sections.

Take another example.  Let’s say your (somewhat obscure) prototype used RS-2’s.  Manufacturer A makes the RS-2 in your paint scheme but the tooling is an older generation, the side panels and hinges are a bit thick as are the grabs and hand rails.  Manufacturer B uses more modern casting technology and the details are ultra fine.  The problem is they only make an RS-3.  Which one do you purchase?  Theoretically model A is more accurate.   As before I’d go with model B.  Even though it isn’t theoretically prototypical, the cross sections of the parts carry more visual impact than whatever is or isn’t going on with the battery box differences on the two units.

One last example.  Let’s say you’re building a station for a modeling contest.  The prototype station windows are of the six pane variety.  You find commercially available six pane castings but, once again, they are fairly thick in cross section.  An ultra fine part is available with thin mullions but it has eight panes instead of six.  Which do you purchase?  Which will be judged more favorably in a contest?  I’d go with the eight pane part because correct cross sections are more important than including an element just to say it’s represented. (I’d also probably get a judging deduction!).

Veteran modelers eventually hit the point where they’ve mastered the basics of assembly skills as well as the ability to lay down a silk smooth layer of any base color.   They’ve also developed an eye for recognizing the most subtle of details and representing them with placeholders.   As a result they can win more than their fair share of contests.  That’s really only about half the way up the learning curve however.    The second half of the curve is much more challenging because you move from the objective task of “representing stuff” to the more subjective one of mastering color and weathering and developing the skill of modeling accurately thin cross sections.


The Accuracy Hierarchy (In order of importance)

1.        Color. Accurately capturing the color of your prototype goes far beyond matching the factory painted base color.  Painting a depot “buff” and calling it done or doing the same by painting a locomotive Brunswick Green won’t cut it.  Our subjects exist in the elements and, as a consequence, assume extremely complex and subtle color patterns.  Further complicating things, the transition between the colors are often finely feathered.  There is no way to short cut the learning curve.  Mastering color takes lots of reading, attending seminars, talking to accomplished modelers, and practice.

2.       Accurate cross sections.  You can’t solve a problem if you don’t know it exists.  The nature of injection molding and white metal casting is such that many of our parts are overly thick.   The more instances where you can replace the thick part with something of the correct size, the better the model will look.  Culprits on locomotives are: overly thick side panels and latches, grab irons, hand rails, cut bars, and air hoses.  On structures problem areas are: hand rails, window mullions, shingles, guy wires, conduits, and architectural moldings.

3.       Representation. (modeling each part that exists on the prototype).   I’m not suggesting that you shouldn’t model specific details if they exist on the prototype.  I’m saying that it’s third on the food chain in terms of visual impact.  It’s also wise to consider the old modelers adage, “no detail, is better than a bad detail”.  This means if the part you need only exists in crudely cast form, you might be better off omitting it from the model.