Instructables Mechanical Birthday Cake 🎂

This is the Instructables Mechanical Birthday Cake!

This project involves a four-component gear mechanism, with two 3D printed colorful characters, one cardboard painted instructables bot, with a bluetooth speaker within its body and a handful of acrylic paint and marker to illustrate the birthday design.

I will take you through the process of how this mechanical cake works and how you can create and customize your own version of a mechanical cake

This Mechanical Birthday Cake is going to be cut with the instructables bot and his fellow friends in the Instructables 20th Birthday party

This project requires a variety of different materials, however it can be customised on your choice and availbility:

List of Materials:

1. 3x 3mm MDF Boards (40cm x 20cm)
2. 1x Acrylic Markers (eg. ENMY)
3. 2x 3d printed files of any character of your choice (eg. Clowns)
4. 1x White and Yellow acrylic paint (Paint bottle)
5. 1x xTool Creative Space (Laser-cutting application)
6. 1x xTool Laser-cutting machine (Physical Printer)
7. 1x Soldering equipment (Speaker support)
8. 1x Mini portable speaker set (Bluetooth Speaker)
9. A few Axels and 4mm screws
10. Corrugated Cardboard (Any size available to your convenience)
11. Hot-glue Gun (Used for all the cardboard applications)
12. *Optional Adventurer 5M Pro (3D printing files)
13. *Optional Any CAD application of your choice (Fusion 360)

I will take you through the step by step process to get this machine ready and the boards cut:

1. Download the xTool Creative Space application
2. Connect your laptop or device with the application to the xTool machine
3. At the top right of the application there will be 2 arrows pointing in opposite directions, click on that to add/switch your device

Get your 3 MDF boards ready and start to design the shape of your project within the xTool application;

1. With the 40cm x 20cm MDF Boards you can think of a gear design that would fit: The gear design used in the project above consisted of a 1x 30 teeth gears and 2x 20 teeth gears.
2. Files of 20 Teeth gear, and 30 Teeth gear are linked below
3. Construct a suitable design to your MDF size and click the "Cut" option on the right side of the application
4. Make sure MDF board is correctly positioned in the machine to where you want your design to be, this can be done through the top right "camera" icon which allows the machine to capture a photo of the MDF's position overlayed with the design you have created

Prepare to start cutting with the machine by following certain safety procedures

1. Once printing starts, the lid of the machine must be closed at all times to prevent any dust or heat being exposed outside
2. Make sure the exhaust hose at the back of the machine is also running which circulates the smoke being exposed from the laser
3. Finally, press the main switch button at the top of the machine while the lid is closed and let the machine do its thing!

Now that we have the MDF gear board ready, we can measure out the proportions required for our Instructables robot which will be sitting on the 30 teeth gear!

1. Make sure that the size of the Corrugated Cardboard available to you fits the size of the the Instructables bot you would like which will sit on top of the gears.
2. Using the Instructables bot design given above, craft the different body pieces of the bot; this should include the 2 body shapes, 2 circular limbs, 2 wooden balls which represent the feet, 4 small cut pieces of the hand and 5 square slabs for the head and the top.
3. The sizing for my Instructables robot started with a height of roughly 15cm and a width of about 7cm. This measurement fit the size of my 30 tooth gear which is placed under the bot
4. ***All body pieces are doubled (eg. 4 hand pieces) in order to give the bot the required 3D look

Connect all the pieces together and make sure that the inside of the body is hollow to allow the *Bluetooth Speaker to fit within it

1. Setup a Hot-glue gun and let it sit and heat before your start using it, also make sure that you put a heatproof mat below the setup to prevent any damage to the surfaces
2. Bring the body pieces together and glue single pieces to each other and hold them together for 10 seconds until you let them sit and dry
3. ***Make sure that the bottom of the body and the limbs are NOT connected yet as the Bluetooth speaker has to be fitted inside the body

In this part of the process, I used a DIY speaker kit which already provided me with some of the essential materials required to construct this speaker. Here are the materials required;

Tools & materials required: your kit (2 speakers, amp/PCB, USB cable, wires), soldering iron (25–40 W), solder, wire stripper/cutters, helping hands or small clamp, heat-shrink or electrical tape, small screwdriver, safety glasses, small file/sandpaper, hot glue (optional), multimeter (optional).

Steps

Open & identify parts

1. Lay out the PCB, the two speaker drivers, the USB cable and any short hookup wires. Find labels on the PCB like L+, L-, R+, R-, VCC/5V and GND. Note speaker polarity — often the + terminal is marked or has a red wire.

Prepare wires

1. Strip ~3–4 mm of insulation from each speaker and USB wire. Twist the stranded wire tips so they’re neat. If your USB cable has 4 wires, you’ll likely only need red = +5V (VCC) and black = GND; green/white are data — insulate and leave them out.

Tin the wires

1. Heat each exposed wire briefly and apply a little solder so the strands hold together (“tinning”). This makes soldering to the PCB much easier.

Solder the speaker wires

1. Clamp the PCB or use helping hands. Place the tinned speaker wire onto the correct pad (L+/L-, R+/R-). Heat the joint with the iron and let the solder flow — remove iron and let cool without moving the wire. Repeat for the other speaker wires. Good joints are shiny and smooth.

Solder the USB power wires

1. Confirm polarity on the PCB (VCC, +5V, or +) and solder the red USB wire there; solder black to GND. Double-check: red → VCC, black → GND. If unsure, don’t power up until you verify.

Test (first power on)

1. Plug the USB into a 5V USB charger or power bank. Start with volume low. Play a test sound. If nothing happens, unplug and check joints, and that the board is getting 5V.

Mount in Instructables Bot

1. Fit speakers into the body of the Instructables bot and make sure that the battery pack is glued on the back of the instructables body. Wires from the speaker to the battery pack should be able to come out through a small hole or dent on the body.

***Troubleshooting: Incase the speaker is not turning on or making any sort of sound. You can trouble shoot through a few ways; Multimeter to make sure that the batteries have the required power, and solder connections again to see if there is any sort of connection problem

Safety first

1. Work in a well-ventilated area.
2. Wear safety glasses. Keep the soldering iron in its stand and don’t touch the tip.
3. Keep other items away while souldering
4. Unplug USB power while wiring.

You need to find a Character file of your choice, this can be found on many 3D printing file websites such as ETSY, Cults 3D, Printables, and Yeggi. Once you have found a file that you like, bring it into the CAD application (Fusion 360) and 3d Print this on the Adventurer 5M Pro. ***This is a optional step, wether you would like to 3D print your characters, construct them with cardboard, or just use a toy figure all options work.

These are the final steps to transfer the file to the 3D printer and actually 3D print it. Which brings your CAD creation to a physical product

1. Plug in a USB drive compatible with Adventurer 5 Pro (must be Fat32) into your computer.
2. Drag the g-code file from your desktop to the USB. Make sure the file is fully copied into the USB and remember to eject it before removing.
3. Turn on the Adventurer 5 Pro 3D printer and pug in the USB.
4. Go to the printing menu (2nd option from the top) and select the USB option.
5. Find your file and select it. Click the green button to copy the file over to the 3D printer and start the printing process.

The printer will heat up and then start printing. This will take a few hours, the exact amount of time for your design to print will be displayed on the printer screen. Once it is finished, remove it carefully and clean up parts with any supports.

Place the character design onto the gears and make sure that the alignment doesnt collide with the Instructables bot

1. Use a temporary sticky tape to place the character down onto the desired position and start spinning the gears slowly watching to see if there is any point of contact/disruption between the Instructables bot and the characters
2. If there is, the best option would be to position the front of the body to the side of the Instructables body, that way when the smallest width is facing the front for the character, the largest width is facing the front for the Instructables bot. Vice-versa
3. If there isnt, your good to go!

Now we take the gear board, the Instructables bot, and the 3d Printed characters into the design room to transform the aesthetic of the birthday celebration!

Once you have all the other materials ready for this final step you need to divide your working areas into a Acrylic Painting section and a Acrylic Marker section

Acrylic Painting section:

Setup the painting station with a newspaper on top of the surface you will be painting on, the White and Yellow acrylic paint, and Thick and Thin Painting Brushes.

First coat both the characters with a base layer of white paint and let it sit for 20 minutes, during this time you can take the Yellow paint and coat the Instructables bot.

After 20 minutes of the first coating, you start to prepare the second coating layer of White again on the characters and Yellow again on the Instructables bot. This process will take 20 minutes which will allow the characters to dry by the end of the second layer

Lastly, apply a third coating of White to the characters and Yellow to the Instructables bot and let it dry. Three coatings is necessary to give the color a bold look which covers the material under the paint FULLY.

After you have painted the 2 characters and the Instructables bot, also paint the board with one layer of white paint which is good enough to cover the MDF material.

Acrylic Marker section:

Using the acrylic markers available to you, ENMY is a great option that I have used. You can take the characters and the Instructables bot and draw over them since the 3 layers of base paint should be dried.

This part is personal preference, for me I chose a colorful clown design which matched the theme of the birthday cake which had colourful sprinkles on it aswell. However you can choose the colors based on your color theme and the colors available to you.

Here are some good Color themes to follow for your designs related to a Instructables Birthday theme:

🎂 1. Classic Birthday Fun

#FFD43B (Yellow) | #FF8DA1 (Pink) | #5BC0EB (Blue) | #FF7F50 (Orange) | #FFFFFF (White)

🤖 2. Instructables + Party Pop

#FFD43B (Instructables Yellow) | #333333 (Dark Gray) | #FF4C4C (Red) | #5BC0EB (Sky Blue) | #9BC53D (Green)

🍭 3. Candy Shop Birthday

#FF9AA2 (Cotton Candy Pink) | #A2D2FF (Bubblegum Blue) | #6B4226 (Chocolate Brown) | #FFF275 (Lemon Yellow) | #FF6B6B (Watermelon Red)

🎨 4. DIY Craft Party

#F5E6CA (Craft Paper Beige) | #FF6F61 (Marker Red) | #4D9DE0 (Crayon Blue) | #7D7D7D (Pencil Gray) | #90BE6D (Yarn Green)

✨ 5. Retro Pixel Birthday

#FCEE09 (Neon Yellow) | #7C4DFF (Purple) | #00FF87 (Lime Green) | #FF5252 (Bright Red) | #000000 (Black)

Glue the colored designs onto your board and 'sprinkle' some color onto the MDF boards to make it look like a cake!

You're Ready To Go!

Play the Birthday song, Sing along, and Dance together

HAPPY BIRTHDAY INSTRUCTABLES 🥳