If the units are not the same, Strater will attempt to automatically convert X and Y units to match Z units. X and Y units are determined based on the map's target coordinate system. Z units are determined based on the cross section's depth units. If no information about the map units exists, and no column unit information is available for the collars table, no automatic conversion is done. So a quick fix is to set the units in one of these two places so your Voxler export is appropriately scaled.
Updated: October 5, 2016