I am designing a new N scale layout, 10’ x 18’, three levels, with two helix… I use RailModeller Pro to design the trackage and want to model the benchwork with SketchUp, I have Pro license. I have been learning furniture design from Fine Woodworking lessons and intend on applying that knowledge towards benchwork design… Of course the first hurdle I see is the Helix and track grade designs. Not sure if that concept of elevation angles is covered in any of the coursework or books I have collected. I think it would be a beneficial topic to share and may indice others to participate.
I’ve done a little bit of N-scale layout modeling in SketchUp. I usually start with a DXF of the centerlines exported from XtrkCAD which I use as paths for Follow Me. For helices I use the Curve Maker extension to draw a helix path and then Eneroth Upright Extruder to extrude a profile or the track. Both extensions are available from the Extension Warehouse.
Don’t bother modeling ties as that will just bloat your file and cause performance problems.
You can use these same tools/methods for modeling the base surfaces if you wish.
The benchwork should be pretty straightforward. Maybe 1x4 frames and 2x4 or 4x4 legs. It’s usefult to figure out where the track goes–at least centerlines–so you don’t have to cut into the framework for things like switch motors.
What version of SketchUp? Please complete your forum profile. Also add the operating system and graphics card model number.
This is part of a helix I modeled a long time ago for someone else just as an idea.
And this is a model of an N-scale T-trak module I designed which includes a Timesaver so the module can be used on its own.
I am mostly interested in getting the benchwork modeled. Keen on helix design idea… I also googled this topic and AI, need to check math, was forthcoming on laying out a 2% helix grade with entry and exit transitions. Some homework to study and learn.
Do you have some general design in mind for the benchwork? Probably basic ladder frames will work for most of it with 2x4 or 4x4 legs and some diagonals to prevent racking. How big is your layout going to be? How many levels?
As for the helices, are they going to be single or double track? For double track plan on no more than 2% for the inner one. The outer will be shallower then. Figure the required spacing which includes thickness of the base material and the height to the top of the rails plus the max height of the tallest power and rolling stock and then a little more for good measure. You can use that height to help you figure out the length of a turn thus the required radius. Don’t let the 2% trip you up. That’s a 2 inch climb in 100 inches. So if you want a 3 in rise per turn of the helix that’s 150 in. circumference or about 24 inch radius. Use a larger radius if you can so you can reduce the slope.
I probably wouldn’t get too entangled in modeling the entry and exit transitions as long as you are keeping in mmind you want to make those transitions gradual. That can happen if your base material is thin and somewhat flexible. Maybe 1/8 in. hardboard.
This is my layout so far. 10’ x 18’ room, different color tracks to denote different layer or transition. Helices and other grades are shown on the lower side view.
RailModeller keeps track of heights and grades, so I can easily transcribe those numbers to the benchwork as I design it. Still in planning mode. Room is currently a storage room as we remodel the house. I plan to post my work as I get ready to construct it and any lessons learned. I am a recent member of the San Diego Model Railroad Museum and an active member of the N Scale club. Our layout was first constructed in 1980 and documentation is non-existent for the most part. My intent is to correct that, but I need to develop some CAD skills. I already started modeling some tracks by tracing a PDF drawing as a layer in RailModeller. Being retired affords me a good bit of hobby time…
