Overhead Spool Holder - Flashforge Finder

Added a 20mm spool drum holder.

(1) Split each support into two pieces so that they can be printed on smaller print beds and without supports. (2) Remixed the spool drum to accommodate filament rolls with a smaller inner diameter [30mm]. Spreader and larger diameter drum [50mm] have not been altered from tech3dp's (https://www.thingiverse.com/thing:2790290) original designs.