Grand Trunk Western Flint Subdivision: 3D Print

3D Print Projects:

Switch Throw Knobs:

The wooden knobs that I have selected to use for my switch throw handles have always been the slow down point when building my switch throws. I am planning on using these for all manual switches across the layout with the current exception of the Owosso (Grand Rapids Sub) branch line. The reason for the slow build process is that the knobs have to be drilled to two different hole diameters. This combined with the fact I am trying to drill dead center of a turned piece of wood that is not always exact, results in imperfections on the finished product.

With all of this in mind, I decided to create these knobs via 3D print so that they will always be exact and they can be installed much more quickly than their predecessors.

Step one was to get the shape and internal dimensions correct.

Wooden knob on left has burn marks from breaking loose in the drilling jig

After the dimensions were correct, I set about creating the color I wanted that closely represented the wooden knobs. I wasn't looking for perfection here as wood tends to differ in color from one piece to the next. I just wanted something close that I could duplicate in the future. I kept careful track of all my color mixes and finally settled on a color that would represent all mainline switches. The beauty of 3D printed knobs is that I will also be able to create them in other colors for things like ladder tracks in yards, industry specific, etc...

I experimented with different color options

The winner is the knob on the right which is closer to a terracotta color

After final testing, I printed enough to last me for a little while

Michigan Signature Guardrails:

Open Parapet Concrete Railing:

For rigidity's sake, I will be adding the concrete lower barrier to the design as well as the curb. This will make the entire bridge railing a one-piece component.

Old Sketch design work for MI Open Parapet Guardrail

CA1-2 Aluminum Bridge Posts:

One project on my agenda was the aluminum bridge rail posts seen in the Trowbridge section and again below.

Old Sketchup design for CA 1-2 Aluminum Bridge Post

Below are the test sections for my Open Parapet Guardrails. They are designed to be modular. I will have longer sections of straight tangent as well as these shorter sections that will facilitate rounding curves. The holes thru the CA 1-2 stanchions will take a #39 piano wire for the upper crash bar.

R4 Iron Railings:

The R4 railing system can be seen with both concrete and cast-iron posts. Having seen many of both, it would appear as if concrete is generally preferred on vehicular bridges whereas cast iron is generally used for railway bridges. There are certainly examples on the contrary, but this seems to be standard practice. As a prototype modeler, I need only concern myself with what is actually there during the time period I am modeling. For more information on the history of this railing design you can go to http://historicbridges.org/info/r4/

Old Sketchup design for Michigan Signature R4 with Concrete Posts

Old Sketchup design for R4 Railing with Cast Iron Posts

I have designed these rail systems to be modular in order to expedite future builds. I also created kits for 50ft sections to act as replacements for existing bridge kits such as RIX. These feature appropriate abutments including an inset where bridge nameplates can be added by modelers.

Alibre Design R4 Concrete Post 50ft Bridge Kit

The concrete post designs tend to follow a 10ft center-to-center spacing which I have created using an 8 frame railing. The Iron post designs can vary from bridge to bridge. I will have a 50ft bridge kit to replace existing kits the same as the concrete design. I have also created 4 and 7 frame sections for customization. In addition, I have also designed these railings with different width sidewalks.

Trial run of R4 intermediate sections as I test proof of concept

Thrie-Beam Guardrails:

The Thrie-Beam guardrail is basically two W-Beam rails combined for additional coverage such as along bridges. Most Michigan bridges that utilize a steel guardrail will transition to the Thrie-Beam 10-15 ft prior to the bridge. This particular piece of SketchUp artwork was found on the online 3D Warehouse. This particular piece of SketchUp artwork was found on the online 3D Warehouse.

The Thrie-Beams I have designed in Alibre are meant to be compatible with the Pike Stuff W-Beam guardrails. Currently I have only done the symmetrical transition. I may eventually venture forward and create an offset version as well.

Alibre Design Thrie Beam Guardrail plain 25ft section

Alibre Design Thrie Beam Transition Symmetrical

Steel Pilings:

There are many areas across the modeled portion of the layout where tie crib retaining walls have been replaced by steel pilings. I scratch built one of these when I did the Shiawassee River module, but again I am looking for speed as I proceed with current and future builds.

Wood trusses:

The Bancroft Truss Company is the first location there will be a demand for these. I will also have several other areas where they can be used.

I stayed with four simple designs to start with, King, Fink, Howe, and Modified Queen with associated Gables. I probably won't need to expand further unless I come across a specific need. I have done singles, stacks of 5, and stacks of 10 for each type.

KING: