There is a 3MF BambuLab Studio Project file with limited painted supports as well as an STL Set prearranged on the build plate, and the individual pieces as separate STLs. 
 

Parts:

• (1) 18"-24” of 4mm Outside Diameter x 2.5mm ID Diameter PTFE tube
• Socket Wrench
• (1) 3/8” x 2 1/2” Hex Tap Bolt
• (1) 3/8” x 1”(or ¾") Washer
• (2) 3M Command 16# Velcro Picture Mounts

Summary:

The bolt and washer will provide support for the spool holder rod and the 3M Command Strips will help insulate the holder from the heat transferring from the enclosure wall.

The only supports needed, if you don’t use the 3MF file, are in the recessed bolt hole area on the underside of the Spool Holder Base. The spool holder is printed lengthwise flat on the bed to increase strength. Filament Guide bears no weight so it can print as is. You don’t have to use the bolt and washer if not printing in PLA if you trust your favorite glue. I use 3D Gloop as it melts the plastic and creates a chemical and mechanical bond. I do not recommend using glue alone, between the heat, vibrations, and weight of spools you don’t want an accident!

Assembly:

Insert the spool holder into the notched circular slot and press firmly until seated tightly. The parts are tight fitting with only .05 tolerance so if you are seeing elephant foot on your prints, then lightly sand the edges before inserting the rod and filament guide into their slots in the holder base. Insert the 3/8” bolt thru the washer, then into the spool holder from the backside, and tighten with socket wrench. The filament guide is not weight bearing so you can pressure fit or glue it into place. Place two 16# Command Strips halfway down Spool Holder Base following the instructions on the package. You can also use (4) of the 6# Command Strips, one in each corner. The beauty of these strips is if you don’t like the position or need to remove, they leave no residue and no scraping is needed to remove!  The Command Strips mounting tape also lifts the holder off the metal surface to prevent heat induction.

When you need to use a single spool just disconnect the PTFE tube from the coupler at the top back corner of the printer. Connect a 18” PTFE tube from the coupler and thru the Filament Guide on the Holder and then insert your filament coming off of the bottom of the spool upwards into the PTFE tube and feed the filament back to the extruder.