Parts. I acquired the following parts: • One N20 6VDC 60RPM gear motor. • One 6VDC power supply with a male coaxial connector. • One coaxial female connector compatible with the power supply connector that fits in a 9mm hole. • Twelve 8mm ball bearings. I 3D printed two of "Star.stl" and one each of the remaining components at .15mm layer height, 20% infill and no supports using the Ultimaker Cura 4.11.0 "Engineering Profile". Assembly and Operation. Prior to assembly, I test fitted and trimmed, filed, drilled, sanded, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on your slicer, printer, printer settings and the colors you chose, more or less trimming, filing, drilling and/or sanding may be required to successfully recreate this model. I carefully filed all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth using small jewelers files and plenty of patience. Using the track and guide, I then manually tested the marble lifting mechanism and carefully filed and sanded the exit and entry track areas as required for smooth entry and exit operation. To assemble the model, I performed the following steps: • Soldered a 100mm length of red wire to the gear motor "+" terminal. • Soldered a 100mm length of black wire to the gear motor "-" terminal. • Pressed "Gear, Motor.stl" onto the gear motor shaft. • Pressed the gear motor assembly into "Track.stl". • Soldered the motor red wire to the coaxial connector "Tip" terminal. • Soldered the motor black wire to the coaxial connector "Ring" terminal. • Applied power to the motor to insure the motor ran counter clockwise when viewed from the motor gear end. • Removed power and slid "Guide.stl" into the track assembly. Secured the coaxial connector to "Base.stl" using the included nut. • Aligned the base assembly with the track assembly, then pressed the base assembly into the track assembly making certain the wires remained clear of the gears (a small dot of thick cyanoacrylate glue may be required to hold the base and track together). • Using a small dot of thick cyanoacrylate glue, glued the two "Star.stl" halves together. • Pressed the star onto the top of the guide (a small dot of thick cyanoacrylate glue may be required to hold the star in place). • Plugged the power supply into the coaxial connector. Once assembly was complete, I plugged the power supply into the mains and added twelve marbles, one by one to the top of the track. And that is how I 3D printed and assembled "Marblevator Christmas Tree". I hope you enjoyed it!