I have done some digging into this issue and have found the following for anyone interested. TurboCAD does not appear to set the units conversion factor or the color associated with an assigned material in exported STEP format files.
For example (NOTE that I am referencing the ISO-10303 AP214 schema for STEP files):
This fixes the scaling issues when the drawing is created in inches in TurboCAD:
-I created a drawing in units of inches, but the exported STEP file was set to units of millimeters. I fixed this in a text editor by changing the following entities:
--CONVERSION_BASED_UNITS(), the first parameter is changed to INCHES. (This is jsut a label, so it has no direct impact on the model, but should be changed for correctness and completeness.)
--LENGTH_MEASURE_WITH_UNIT(), the first parameter is changed to LENGTH_MEASURE(25.4). (This sets the conversion 25.4 mm = 1 inch).
This fixes the colors in the STEP model:
TurboCAD appears to default all color assignments in a STEP model to BLACK (i.e. COLOUR_RGB('',0.0,0.0,0.0))
The three decimal values represent Red, Green, and Blue respectively with values between 0.0 and 1.0.
So If I use the Metals > Chromium assignment for pins on an IC, then I expect the STEP model to be populated with COLOUR_RGB('Chromium',0.68,0.68,0.68) for every facet of the pins.
This brings me to my request to TurboCAD to fix the tool, since every facet must have its color set, it is a very tedious task to manually edit the colors in a text editor because even on the simplest of designs (a 4-pin IC for example), there are many facets to change (60 - 70 in the attached file) and there is no way to identify what facet is being changed with out editing the ASCII text and loading the model in a viewer to see if the correct facet was changed.
For what it is worth, I believe there is a similar issue in the way TurboCAD exports to SAT files, but I have not dug into that one very deep. I have only observed one occurance where the colors were imported incorrectly and stopped there since my focus was on the STEP format.
I have submitted a ticket to TC Support. Hopefully I can message the perceived issues correctly and see at least an acknowledgement that the issues exist.