If you have been following along, you will have read that I wasn't happy with the results of the first version of the coal tipple support structure, the part of the building that holds the main sheathed building up in the air. Using Evergreen Styrene's delicate styrene parts made it look great, but it caused the model to warp as more and more pieces were attached to it. It is my hope that this second version is going to be "the one".
So, in reviewing what I have learned from the first version, I am going to make some changes to how I build the second one. First, I am going to build it in-place on the module. This makes it harder to construct (due to its overall size and complexity), but that guarantees that the parts fit the concrete pads I already have on my module, and since it will be directly mounted to the module, that should eliminate any warping and thus misalignments. Second, I am going to switch from Evergreen styrene to Plastruct's ABS strips. Plastruct's material is a bit thicker, or cruder, but I have used it before and it does not warp at all. When the whole support structure is painted in "weathered black", the thickness of the columns' webs should be all but unnoticeable. Third, I am going to create a CAD drawing of the whole structure before building it. Fourth, there will be a slight compromise in the construction materials as Plastruct doesn't make scale 10" C-channels in their ABS material, so I'll be using scale 12" H-columns instead for the main vertical and horizontal beams.
When I started the construction of the first version of the support structure, I had a 3D CAD program on my computer, but it was just too difficult to use, especially for complex designs as this support structure. However, while I was building "version 1", I discovered OpenSCAD and really liked its approach. Instead of doing a bunch of heuristics with the mouse and the CAD program misinterpreting my intentions, or dealing with the complex user interface of the program itself, OpenSCAD makes it possible to simply type in the dimension you want along the X-, Y-, and Z-axis. There are a few commands to learn, but they are all well-documented. Using that CAD program, I built the design you see here.
This close-up shows the design for how the parts attach to each other. The vertical columns are a scale 12" square H-columns. I will be using the same material for the horizontal pieces going between the long sections (the ones going away from the view shown here). In between the H-columns (going left-to-right here) will be 4"x8" I-beams that fit within the webs of the H-column.
This screen capture shows some of the improvements made to the drawing itself. I changed the colors on some of the parts to make things easier to see. I also added the concrete footings, which are now based on the actual locations of where they are on the module upon which this structure will reside. Since those are already installed, I figured that it is best to have the design match those. You are looking at the west side of the structure, with the Chartiers creek and the mine's entrance being on the right. The front of the module is on the left. Note that the center vertical H-columns are taller than the outer ones. This is because I built the main building such that its floor is inset from the bottom of the building. So, these H-columns are taller to still make contact with the main building's floor.
All of the cross-bracing needs to be added next. Stay tuned...