I designed, 3D printed and assembled "Christmas Tree, 2023" for my wife for use on our Christmas table, our granddaughter's dollhouse, and on my wife's nightstand. She asked that it be operated from a wall outlet so no batteries were required.

As usual, I probably forgot a file or two or who knows what else, so if you have any questions, please do not hesitate to ask as I do make plenty of mistakes.

Designed using Autodesk Fusion 360, sliced using Ultimaker Cura 4.12.1, and 3D printed in PLA on Ultimaker S5s.

Supplies

Soldering iron and solder.

Heat shrink tubing.

Thick cyanoacrylate glue.

Step 1: Parts.

I acquired the following parts:

One N20 6VDC 35RPM gear motor.
Eight 3MM diameter by 1MM thick neodymium magnets.
One 3VDC slow color cycle LED (optional flickering).
One 100OHM 1/8WATT resistor.
One .1UF ceramic disk capacitor.
One 10MM ID, 15MM OD, 16.5MM flange, 4MM thick ball bearing.
One 3VDC 500MA power supply.

I 3D printed the following parts:

One "Base.stl, .1mm layer height, 20% infill.
One "Coupler (38t).st, .1mm layer height, 20% infill.
One "Cover.stl, .06mm layer height, 20% infill.
One "Motor Gear.stl (12t)", .1mm layer height, 20% infill.
Two "Star.stl, .06mm layer height, 20% infill.
One "Tree.stl, .06mm layer height, 20% infill.
One "Wire Guide.stl, .1mm layer height, 20% infill.

This is a precision 3D print and assembly model using at times small parts in very tight spaces. Prior to assembly, test fit and trim, file, sand, polish, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on you printer, your printer settings and the colors you chose, more or less trimming, filing, sanding and/or polishing may be required. Carefully file all edges that contacted the build plate to make absolutely certain that all build plate "ooze" is removed and that all edges are smooth. I used small jewelers files and plenty of patience to perform this step.

Step 2: Base Assembly.

To assemble the base, I performed the following steps:

Soldered a 50MM length of red wire the gear motor "+" terminal and a 50MM length of black wire to the gear motor "-" terminal.
Pressed "Motor Gear (12t).stl" onto the gear motor shaft.
Pressed the gear motor into "Base.stl" with the wires routed as shown.
Trimmed the leads of the resistor to 10MM then soldered one end of the resistor to the LED cathode lead.
Soldered a 50MM length of black wire to free end of the resistor then a 50MM length of red wire to the LED anode lead.
Slipped heat shrink tubing over the anode lead.
Slid the LED wires and resistor into "Wire Guide.stl" then folded the wires up into the slot in the wire guide.
Pressed the wire guide assembly into the base assembly with the wires routed as shown.
Soldered the red and black wires together with the capacitor in between.
Removed the plug from the power supply, stripped the insulation from the cover, red and black wires, then tied a knot in the cable to act as a strain relief.
Soldered the power supply red wire to the red wires and the power supply black wire to the black wires.

Step 3: Tree Assembly.

To assemble the tree, I performed the following steps:

Pressed four neodymium magnets in "Coupler (38t).stl" with matching polarity.
Pressed four neodymium magnets into "Tree.stl" matching the polarity of those in the coupler.
Glued the two "Star.stl" together then pressed the star assembly into the top of the tree assembly.

Step 4: Final Assembly.

For final assembly, I performed the following steps:

Pressed the ball bearing into the base assembly such that the flange was flush with the base top.
Pressed the coupler assembly into the ball bearing while aligning the coupler ring gear with the motor gear.
Magnetically attached the tree assembly to the coupler assembly.
Slid "Cover.stl" over the tree, aligned the four small base snap pins with the cover snap holes, positioned the power cord knot inside the cover, then snapped the cover onto the base.

And that is how I 3D printed and assembled "Christmas Tree, 2023".

We hope you enjoyed it!