I certainly assume there needs to be a smooth transistion from flat track to a grade. If you use a single radius transistion what is a reasonable radius for reliable operation? For a realistic operation? Does this radius change depending on the grade? Is it necessary to "ease" (larger radius at the start & end) into and out of the transistion? I developed the table below with a wide range of values since I don't know the answers to the above questions. Fairly sure the calculations are correct. For example, a 160" radius transistion to a 3% grade would require 4.8" of track with a 0.072 inch spacer at the end and spacers of 0.003, 0.012, 0.028 and 0.050 at the 1,2,3 & 4 inch points. Do these values seem reasonable? I would assume for XtrkCAD (or any other track design program) I would then use a 4.8" length of track and define 0.0 and 0.072 for the height of the two ends.