Mechanical Music Box: Animation

Pre-Modeling: Defining the Project Topic & Roadmap

In this project, I wanted to model and animate a mechanical music box. I find the mechanism interesting and although it looks, it is made up of small parts that come together to play a specific melody. I got myself a music box and took it apart to better understand how it works.

I decided to model on Inventor which is ideal to model mechanical parts. Having previously worked on a product teardown project on Solidworks made me realize the potential and convenience of parametric modeling, which allows to change dimensions when necessary and utilize constraints and features. I was able to transfer the skills and knowledge I earned onto this project. I chose to work with Inventor, an Autodesk product, not Solidworks, to explore a new platform and see how it compares.

Shown below are images of the components of the mechanical music box (which plays the song Here Comes The Sun) I took apart. I measured and documented each component, analyzed the material, and further strategized ways to model.

3D Modeling: Inventor

Design Strategies & Considerations

• I modeled some parts by inserting images I took or borrowed online in Inventor and drawing on them, which was helpful to figure out dimensions relative to each other. I resized each image and put down a function so that what I drew on top of the image would match real-world dimensions.

• I assigned the materials I identified above to models from the Inventor library. These would accurately reflect the material texture and surface quality.

Challenges

• Modeling the cylinder components. This was the most challenging part because of the pins that correspond to notes. I could not place them at exact locations and the only way I could think of is making use of planes on edges and doing multiple circular patterns.

• Figuring out how to make the string of the vibration plates move at separate times as they get hit by the pins on the turning cylinder. Because Inventor does not have layers as I am used to, I drew it on AutoCAD. Different layers would dictate the movable parts of models imported to 3Ds Max, . I assigned 18-20 different layers for strings and drew on top of an image. It took me a long time to give its exact shape and make sure all the layers are kept separate, for example when removing geometry from different parts of the model.

• Modeling the screws in 3D. Based on screw type and size, I first drew the screws using the thread feature on Inventor. However, I then realized it does not realistically represent a screw in 3D, with 3D spiraling turns and depth. That's why I watched a tutorial on youtube and used the helical coil feature, adjusting the pitch and the height.

Animation: 3ds Max

Animation Considerations

• Because it is an exploded view of a product, it made sense to use more frames and animate in a slower way when exploding the music box and then making the parts come back together to form the whole piece.

• It is important to adjust camera angles properly to show how different components come together in building the product. Smooth transitions and zooming in and out make it more visually aesthetic and understandable.

• Creating a plain white background for product display (like in a studio) would reveal the details and provide depth to the scene.

Challenges

• Putting all the parts together was time-consuming since I would set different pivot points for each part and then snap those points to the edges or faces of other parts. I wish I used Inventor Assembly.

• 3Ds Max snapping feature not being as good as AutoCAD. I ended up copying and pasting the coordinates of each component at the initial scene to be able to connect them the same way accurately and form the whole product.

• Realizing errors with dimensions when putting together components on 3ds Max. Since I measured manually using a caliper and could not find detailed dimensions online. So I had to go back to Inventor, edit my sketch, adjust the size, extrude, and import back to 3ds Max.

• Inventor material library not transferring over to 3ds Max. Most materials I assigned on Inventor did not transfer over to 3ds Max, although some did, they could not render through Arnold. That's why, I had to find high-quality images online which would best reflect the material when enlarged and mapped.

Rendered Images