Servo Bear: the Little Laser-Cut Buddy Who Says Hello

I started this project because I am new to Arduino and wanted to learn more about how servos worked but also to animate something that could be fun to display. I affectionately call it "Servo Bear".

He's a little layered wooden bear who waves “hello” whenever you press a button. The waving motion lasts for about ten seconds and has a surprisingly friendly feel to it. I added a small card next to him that says “Say Hi!”, partially inspired by the speaking tradition at my school, Washington & Lee, known as the “Say Hey” culture. People acknowledge each other on campus, even strangers. I wanted to turn that tradition into a physical interactive piece something that literally waves back.

Most of this project revolves around three core skills:

1. designing vector files in Inkscape,
2. laser cutting and layering 6 mm birch plywood, and
3. programming basic servo control using an Arduino Uno.

I also used Claude Code during this process, which helped me understand how to structure Arduino logic, especially timing and button-press detection. That support made it easier to focus on the creative part: building a cute animated bear.

My hope is that this Instructables breaks down the project into clear, replicable steps that any beginner can use to learn about laser cutting and servo motors.

Supplies

Materials

1. 6 mm birch plywood
2. Wood glue
3. Hot glue sticks
4. One 9 V battery
5. One SG90 micro servo
6. One push button (momentary switch)
7. Assorted jumper wires
8. Small 3D-printed scrap blocks (approx. 5 cm × 3 cm and ~2" × 1.5")
9. Arduino Uno
10. Breadboard
11. “Say Hi!” note card (optional)

Tools

1. Laser cutter
2. Inkscape for vector design
3. Hot glue gun
4. Sandpaper (optional)
5. Access to Claude Code or another AI coding assistant (optional but helpful)

Step 1: Designing the Bear in Inkscape

I started by sketching out simple oval-based shapes for every part of the bear. Using a consistent geometry helped everything feel cohesive once assembled.

Vector Design Process

1. I used the ellipse toolto build every body part so the silhouette stayed soft and cartoon-like.
2. The face and ear details were engraved rather than cut through. Simple line engraves darken beautifully on birch plywood.
3. I made sure every stacked layer aligned using the same center point. This is essential when building multi-layer laser-cut characters.
4. I also added a cutout line in one arm so the servo horn could be glued directly onto it.

Digital Fabrication Concepts Used

This step applied two fundamental concepts from class:

1. 2D vector fabrication workflow: building cut/engrave paths, exporting to the laser cutter’s format, and planning layer order.
2. Designing for assembly: anticipating how layers create thickness and depth.

Preparing for the Laser Cutter

Make sure your file includes:

1. Red hairline strokes for cuts
2. Dark filled shapes or black lines for engraves
3. All strokes expanded properly (no grouped paths or clipped shapes)

Save your final file as SVG and export to whatever format your laser cutter requires.

Step 2: Laser Cutting & Organizing the Layers

I used 6 mm birch plywood because it’s sturdy enough for servo motion but still cuts cleanly. The engraves show up beautifully on birch as well, giving the bear a warm, slightly cartoonish look.

Cutting Tips

1. Slow, clean engraves help define the face and ears.
2. Label the back of pieces lightly in pencil so you don’t mix up symmetrical shapes.
3. Keep the belly circle un-engraved so it stays lighter, adding a nice 3D pop on the front.

Post-Processing

You can lightly sand edges if needed, but I left most pieces as-is; the laser burn actually adds a soft outline that helps the bear visually pop.

Now you should have ten individual piecesready for assembly.

Step 3: Layering & Gluing the Wooden Bear

Layer Order

Glue your layers in this order (back → front):

1. Legs
2. Main body
3. Arms
4. Belly
5. Head
6. Face oval
7. Ears

I used wood glue for the structural layers so they bonded firmly, but used hot glue where I needed quick setting, especially around the servo.

Adding the Servo

1. Position the servo behind the left arm
2. Hot glue the servo horn directly to the underside of the arm.
3. Then hot glue the servo body to the back of the main body layer, making sure it can freely swing about 70 degrees.

Because the servo sits on the back, all electronics stay hidden when viewed from the front.

Standing Support

I used some 3D printed scraps pieces that were lying around they worked quite well:

1. One piece about 5 cm × 3 cm forms the base.
2. Another piece about 2" × 1.5" acts as upper support.

Glue both to the bear’s back at slight angles until he stands comfortably.

Step 4: Electronics, Circuitry & Programming

I wired my circuit on a breadboard and kept everything mounted behind the bear. The whole system runs from a 9 V battery powering the Arduino, while the servo draws 5 V from the Arduino’s regulated pin.

Circuit Overview

1. Servo signal → Pin 9
2. Servo power → 5V
3. Servo ground → GND
4. Button → Pin 2 and GND

No resistor is needed for the button (thanks to Arduino’s internal pull-up resistor).

How It Works

1. When the button is pressed, the Arduino detects the change from HIGH → LOW.
2. A timer starts, and the servo creates a back-and-forth waving motion for 10 seconds.
3. After the timer ends, the arm returns to its resting position.

The Code

You provided this code, and I'm including it exactly as-is. It’s clean, readable, and structured well for a beginner-friendly project. It uses non-blocking timing with millis(), which avoids freezing the program and keeps motion smooth.

Step 5: Testing, Final Assembly & Displaying Your Waving Bear

Testing Tips

1. Start by unplugging the servo, uploading the code, then reconnecting the servo.
2. If the servo twitches, make sure ground is shared consistently.
3. Check that the arm doesn’t collide with the belly or head layer during its motion.

Display

I placed a handwritten card next to mine that reads “Say Hi!”, connecting the project to the welcoming culture at W&L. It gives the piece personality and context.

The circuitry sits behind the bear, so from the front it looks like a small wooden character politely greeting you whenever you walk by.

It’s surprisingly endearing.

Step 6: Reflection

This project taught me a lot more than just how to make a servo wave. It covered the entire digital fabrication pipeline from idea → design → toolpath → cutting → assembly → embedded interaction.

Key Lessons

1. Understanding Servo Logic

Before this, I barely understood the difference between delay() and using millis(). Now I know:

1. how to map timed intervals into smooth motion,
2. how to detect button presses without blocking the program, and
3. how important consistent grounding is in small circuits.

Controlling physical motion from code feels like a huge milestone.

2. Thinking in Layers

Designing something 2D that becomes “2.5D” when stacked taught me a lot about:

1. visual depth
2. using engraves to highlight features
3. structuring files for multi-layer laser cuts

This helped me understand material thickness and how layers align during fabrication.

3. Recognizing the Role of AI Tools

Claude Code did much of the code writing but through I was able to understand as it explained servo speed control, timing, and state machines in a way that made sense. That guidance let me focus more on creativity and less on getting stuck on syntax.

4. Iteration Matters

My first servo placement didn’t wave smoothly; it collided with the head. My second attempt lacked glue support. Only on the third try did it move cleanly.

Each iteration got better as I learned how to integrate electronics with physical form.

5. Reflection

Even though the electronics are exposed in the back, the bear feels like a finished object. It's simple, personable, and technically functional.

Servo Bear now sits proudly on my desk, waving whenever someone presses the button, reminding me of W&L’s speaking tradition and how approachable learning new tools can be.

If you're new to Arduino or digital fabrication, this is a great intro project with a fun payoff. And if you build your own version, I hope your bear says “hi” just as enthusiastically as mine does.