I have been absent for a couple of months so this is what I have been doing since I finished the basic spline helix for my under-construction N-scale layout. 

First of all, I do not use CAD for drawing the layout.  I use old school sketches and presentation style programs, such as Powerpoint and/or Keynote, to draw the layout's support structure. See the sketch drawing of staging level below.

It has been a while since I updated the progress made with the spline helix so here is where I am now. 11 November. Added Oval Helix Virtual Grade estimations/calculations used for this project.

Last month I described in words the laminating process.  I took a few pictures the other day when I was cutting up two sheets of masonite hardboard into strips for the spline helix that I am building.  This is my method and there may be others but this is how I do it. Updated 6 Sep with additional pictures.

Since my last post, I've had an issue with the min-split HVAC not cooling properly over the 12 straight days of 100+ degrees.  I had to rearrange the room to give the technicians full access to the inside unit of the mini-split.  Now the helix is temporarily in the middle of the room which does make it much easier to work on and test.  Although, I did try to solder one of my fingers to the track this past week. Added info & pics on 31 August below.

The spline roadbed helix story continues.  I have other projects around the house so I have only been working on this project part of the time as well as learning and documenting the process as I go. New pictures and a movie were added on 4 and 9 August to this section.

Since I had to decide what type of construction (spline vs other) to use in two helixes, and with the comments that I received from the post I made the other day, I've come up with a concept on how to build a test helix that combines spline sub-roadbed with two straight sections to reduce the virtual grade.  The first jpg (n-scale helix top design) depicts a general drawing of the helix entrances and exits.  The second jpg (n-scale helix 1) depicts how I plan to construct the test helix.  I was particularly concerned about the gaps on the sides and the middle that woul

I am in the process of rebuilding my N-scale layout in a dedicated out-building (interior space 15'3" x 24'11").  The out-building is heated and air conditioned.  The layout was previously in a large room in my house but had to be torn down to make room for family (kids & grandkids).  That layout was an N-scale version of Bruce Chubb's original Sunset Valley but with an ATSF flair.  The concept for the new layout is blending some of my old one with some of CHuck Hitchcock's previous ATSF Argentine Division but in a freelanced fashion.