Happy Valentines Day 2025!

An animated heart for my Valentine!

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 comment 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.

Soldering Iron and Solder.

Thin double sided tape.

Thick cyanoacrylate glue.

I acquired the following parts:

1. One N20 6VDC 50RPM gear motor.
2. One 2 AAA cell switched battery box.
3. Four 3mm diameter by 1mm thick neodymium magnets.

I 3D printed the following parts at .15mm layer height, 20% infill:

1. One "Base.stl".
2. Four "Bolt (M8 by 8).stl".
3. One "Cam and Gear (10t 1.5m).stl".
4. One "Card.3mf".
5. One "Cover.stl".
6. One "Cross Journal Mount Joiner.stl".
7. One "Cross Journal Mount, Lower.stl".
8. One "Cross Journal Mount, Upper.stl".
9. Two "Cross Journal.stl".
10. One "Gear (10t 1.5m) and Axle.stl".
11. One "Gear (10t 1.5m).stl".
12. One "Gear, Motor.stl".
13. Two "Hand.stl".
14. One "Hat.3mf".
15. Two "Heart, Eye.3mf".
16. One "Heart, Mouth.stl".
17. One "Heart.stl".
18. One "Jeans, Cam Guide.stl".
19. One "Jeans.3mf".
20. One "Shoes.stl".

This mechanism is a high precision print and assembly using at times very small precision 3D printed parts in confined spaces with highly precise alignment. 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.

This mechanism also uses threaded assembly, so I used a tap and die set (M8 by 1.25) as required for thread cleaning.

To assemble the base, I performed the following steps:

1. Snapped "Cross Journal.stl" into "Cross Journal Mount, Lower.stl".
2. Snapped the cross journal holes on "Jeans.3mf" around the pins on the cross journal.
3. Glued "Shoes.stl" onto the legs of the lower cross journal mount assembly such that they were 4mm above the bottom of the two the legs.
4. Pressed the jeans assembly onto "Cover.stl" noting the bottom of the legs are flush with the bottom of the cover leg mount holes.
5. Slid "Gear (10t 1.5m) and Axle.stl" up into the left leg.
6. Secured the gear and axle in the left leg using "Gear (10t, 1.5m).stl" making certain the gears rotated with ease.
7. Glued "Jeans, Cam Guide.stl" into the jeans assembly making certain the cam guide hole was centered left to right in the jeans assembly.
8. Snapped the remaining "Cross Journal.stl" into "Cross Journal Mount, Upper.stl".
9. Threaded "Cross Journal Mount Joiner.stl" into the upper cross journal mount.
10. Positioned "Cam and Gear (10t 1.5m).stl" into the cam guide hole and meshed the gears.
11. Slid the upper cross journal mount assembly through the cam and gear hole and threaded it into the center hole in the lower cross journal mount.

To assemble the heart, I performed the following steps:

1. Glued the two "Heart, Eyes.3mf" into "Heart.stl".
2. Glued "Mouth.stl" into the heart assembly.
3. Pressed two magnets into the magnet pockets of the heart assembly with matching polarity.
4. Glued "Arm, Left.stl" into the left arm hole in the heart assembly.
5. Glued one "Hand.stl" onto the end of the left arm.
6. Glued "Arm, Right.stl" into the right arm hole in the heart assembly.
7. Glued the remaining "Hand.stl" to the end of the right arm.
8. Slid the heart assembly over the upper cross journal assembly making certain the cam is through the heart lower hole then engage the cross journal pins with the cross journal pin holes in the top of the heart assembly.

For final assembly, I performed the following steps:

1. Soldered the battery box wires to the gear motor such that the motor shaft spun clockwise when viewed from the motor shaft end of the motor (imagery not shown).
2. Pressed the gear motor into "Base.stl".
3. Pressed "Gear, Motor.stl" onto the motor shaft.
4. Secured the battery box to the base assembly using double sided tape making certain the switch was located within the switch slot on the base (imagery not shown).
5. Slid the base assembly into the cover and secured in place with four "Bolt (M8 by 8).stl".
6. Glued "Card.3mf" to the right hand.
7. Pressed two magnets into "Hat.3mf" matching the polarity of the magnets in the top of the heart assembly.
8. Magnetically secured the hat to the heart.

And that is how I 3D printed and assembled "Happy Valentines Day 2025!".

I hope you enjoyed it!