Almost all of the drawings that I post here on my blog are based upon proportions.  I like using proportions because it makes scaling a project far easier.  I did the same with the Japanese Toolbox project.  I approached this knowing that the height, width and length will be variable based upon need and as such would be impractical to constrain with proportions. Instead I concentrated on the peripheral parts of the toolbox.  The proportions are based upon the thickness of the handle.  It’s doubtful that I will ever alter the thickness of the handle enough to change the size of the other parts so proportions for this project are mostly an exercise in consistency.

What I want to do now is explain how I work out the actual size of the elements based upon my stated proportions.  In the lower left corner of the drawing you will find a “Module Scale”.  The module (D) being the key starting dimension upon which all others are derived.  For this project (D)=handle thickness which I will be making 36mm.  The “Module Scale” simply shows this divided into proportional parts.  In this case halves and thirds.  Everything on the drawing is drawn to scale so that a pair of dividers can be set to a distance on the “Module Scale” and matched to a distance on the item drawn.  The reverse holds true as well of course.

So here is a breakdown of the derived dimensions.

• 1D=36mm (handle thickness)
• 2D=72mm (handle height)
• 1/2D=18mm (thickness of sides, ends, end caps and lid battens)
• 1/3D=12mm (bottom and lid thickness)
• 7/3D=84mm (width of end cap)
• 7/6D=42mm (width of lid battens)

Hope that helps those of you who may be trying to make sense of my drawings.

Part 1 Greg Merritt