Addition of cab support end sills

    Continued work building up the full design of the back chassis section, one of three sections that make up the entire chassis.  It was necessary to subdivide the overall chassis structure into three sub-assemblies in order to be able to build the chassis in the 3D printer.  Each sub-assembly needed to be no longer that about 10".
    The back section contains two side frames, a front spacer, rear spacer and several detail sections.  For this blog posting the side rails, front spacer, rear spacer and now the cantilevered sill sections that support the cab rear and a number details are finished, design-wise.  Each component has been consuming about 4-6 hours of effort to complete the 3D design model which can then be integrated into the overall back section assembly.

     The rear sill sections are cantilevered out from the side rails.  The locomotive erection and section drawing is shown at left with the rear sill portion highlighted.
    At left is the end view of the sill, below is the side view.  After much evaluation and examination of other material, the side and end views provide a general idea of how the sill is constructed in the plan.
    The sill has the function of supporting the rear panel of the cab and a number of pipes and other details associated with steam locomotives such as water injectors, etc.

    The rear view of the locomotive section shows the main cantilever section shown highlighted.  At the end is a small box that extends the overall sill out to the edge of the cab rear and provides mounting for some details.
    For this design effort only the sill structure is developed, details will be developed and added on later.







    The drawing at left shows the 3D CAD model of both the right and left sill structures.  They are mirror images of one another.  They are composed of individual plates in a manner very similar to the prototype locomotive.  Bolt detail was added where shown on the plan.

   The 3D CAD model at left illustrates the end sills on each side of the side rails outboard of the rear spacer.  A number of smaller details remain to be added later.