Once you have modelled the item, check it for correct sizing and position by importing the base parent figure geometry at 100% scale (1.0 poser scale size for hex) and adjusting size and position until it is fitted as it will appear when complete

(import the parent model with an import scale of "1"  and a unit size of "ft" selected, with "merge groups" check in Hex's import settings window, the parent figure is just to addjust scale and fit so loading it with it's groups will just get in the way).

After finnal adjustments are made to your new figure and groupings have been set, delete the parent model and save the item out by "exporting wavefront obj. with the following settings;

1)export scale; "1"

2. unit size; "ft"

(see included pic for settings example in Hexagon)

*Important note! make sure that "merge groupings" is turned off before export