SUBROUTINE ESLOFTX User Guide. Rotor Blade Lofting in X/CROTOR: ESLOFTX is a port and further development of ESLOFT for DFDC vES2. Though most features are common, this document pertains specifically to the XROTOR/CROTOR version. ESLOFT is a tool for getting rotor designs out of CROTOR and into CAD for subsequent 3D modeling, meshing or manufacture. This is accomplished by calculating on the rotor geometry along with blade thickness (input) and airfoil geometries (parent airfoils) to generate points files which can be lofted in 3D CAD systems. The definition of blade thickness plays a central role in ESLOFT. A smooth thickness distribution is desired for both aerodynamic and structural reasons. Since chord is defined by the blade design, defining the distribution of thickness (t) or thickness/chord (t/c) along the blade allows for section t/c to be determined at any station radius. Sections are interpolated to the required t/c from parent airfoils bounding that t/c (or extrapolated as necessary - see below). A uniform paneling scheme facilitates the interpolation of parent airfoils. Each parent is paneled with the specified points per side and density factor (le/te) relative to the airfoil arc length (te-le), allowing for simple linear interpolation between bounding parent airfoil coordinate points relative to t/c.