Windup Animated Christmas Music Box

Our youngest daughter asked if I could create an animated windup music box for Christmas, so here it is, "Windup Animated Music Box". I hope you like it Erika!

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

Hand held rotary tool with cutoff blade.

Thick cyanoacrylate glue.

Step 1: Parts.

I acquired the following parts:

1. Eighteen 3mm diameter by 1mm thick neodymium magnets.
2. Sixteen 2mm ID by 5mm OD by 2.5mm thick bearings.
3. One by 10mm ID 15mm OD by 4mm thick ball bearing.
4. One 2mm diameter steel rod.
5. One music box (https://www.amazon.com/Sankyo-Musical-Movement-Option-Jingle/dp/B0B2KV8CSL/ref=sr_1_2?crid=2WAMECD6GTRV4&dib=eyJ2IjoiMSJ9.kuOqsNQCIeQsp1cX2XBmFRhjNqKoxb0Bxr7K01DOZ6q3ZDHSZnIuOFjwC-qaC2K29qs1tGAhxkbCHL_zurhHoG_JPErp2riax8pqThWqLSTHJwBIBR_OGbBuOshOaFA3Pq8a-ME5Q9285gMCtHUFAE-bL70IpAlTRxT9atjnV1YLzf7C5ceMWePKUj6MIQngUU-8rHmWabHRlQXsap2MLESjQKHyG8qYJCSFqnP22WL0XUJrWolBzCjn1b3ds_exjlUc0tHpvMSpA08sLosTrBDG-1fKJxrNfFbME75JEJ4.WecZUBPPOClJo7SHElYC0Gn77mxyuW6MVcQ7Bz2hAhA&dib_tag=se&keywords=play%2B(jingle%2Bbells)%2Bmusic%2Bbox&qid=1765649090&sprefix=play%2Bjingle%2Bbells%2Bmusic%2Bbox%2Caps%2C120&sr=8-2&th=1).

I 3D printed the following parts at .15mm layer height, 20% infill and no supports:

1. Two "Car.stl".
2. One "Drive Gear (2m 8t).stl".
3. One "Engine.stl".
4. One "Face Gear Bolt (m8 by 1.25 by 6).stl".
5. One "Face Gear Mount.3mf".
6. One "Face Gear.stl".
7. Four "Leg.stl".
8. One "Mountain.3mf".
9. One "Music Box Mount.stl".
10. One "Sation.stl".
11. One "Station Roof.stl".
12. Four "Tree Short.3mf".
13. Four "Tree Tall.3mf".

I've also included the individual files I used to create the dual extrusion (.3MF) files.

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.

Step 2: Assemble the Music Box Mount.

To assemble the music box mount, performed the following steps:

1. Attached the music box to "Music Box Mount.stl" using the three included screws then threaded the included wind up knob onto the music box winding axle.
2. Pressed "Drive Gear (2m 8t).stl" into the music box cylinder.

Step 3: Assemble the Face Gear and Face Gear Mount.

To assemble the face gear, I performed the following steps:

1. Pressed two 3mm diameter by 1mm thick neodymium magnets into a magnet pocket in "Face Gear.stl"
2. Pressed two 3mm diameter by 1mm thick neodymium magnets in the same polarity as the first two into the adjacent magnet pocket in the face gear assembly.
3. Skipped one magnet pocket hole from the previous two magnets, then repeated the previous two steps.
4. Repeated the previous step for the remaining magnets.
5. Cut four 10mm lengths of 2mm diameter steel rod.
6. Positioned one 2mm ID by 5mm OD by 2.5mm thick ball bearing into a ball bearing pocket in face gear assembly then pressed one 12mm length of steel rod through the pocket holes and bearing making certain the bearing rotated with ease.
7. Performed the previous step for the remaining three bearing pockets.
8. Pressed the 10mm ID by 15mm OD by 4mm thick ball bearing in the center of the face gear assembly.
9. Pressed the face gear assembly center bearing over the mounting tower inside "Face Gear Mount.3mf" then secured the face gear to the face gear mount using "Face Gear Bolt (m8 by 1.25 by 6).stl" making certain the face gear rotated with ease.

Step 4: Assemble the Train.

To assemble the train, I performed the following steps:

1. Cut six 14mm lengths of steel rod.
2. Pressed two 14mm lengths of steel rod into the axle holes of "Engine.stl".
3. Pressed one 3mm diameter by 1mm thick neodymium magnets into each of the two magnet pockets in the engine assembly matching the polarity of the face gear magnets.
4. Pressed four 2mm ID by 5mm OD by 2.5mm thick bearings onto the ends of both axles.
5. Repeated the previous three steps for the two "Car.stl".

Step 5: Final Assembly.

For final assembly, I performed the following steps:

1. Carefully aligned the drive gear with the face gear, then attached the music box mount assembly to the face gear mount assembly using four "Leg.stl".
2. Using small dots of glue, attached "Mountain.3mf" to the assembly making certain the mountain spanned the track evenly for engine and car clearance.
3. Using small dots of glue, attached "Station Roof.stl" to "Station.stl".
4. Using small dots of glue, attached the station and trees to the assembly.

And that is how I 3D printed and assembled "Windup Animated Music Box".

I hope you enjoyed it!