From Idea to Prototype — Tavrida Robotics

Building your own robot is a unique opportunity to combine mechanics, electronics, and programming in one project. Thanks to affordable 3D printing and open platforms, anyone can now build a working robot — from a school student to an engineer exploring a new field. In this article we walk through the full cycle of building a simple 3D-printed robot, from the first idea to a working prototype.

Step 1: Concept and Technical Specification

Before opening a CAD program or picking up a soldering iron, you need to clearly define what your robot is supposed to do.

Define the basic functionality:

Will the robot move around the room (wheeled or walking platform)?
Will it manipulate objects (robotic arm)?
Will it interact with the environment using sensors?

For a first build, a wheeled robot with obstacle avoidance or a 3–4 DOF robotic arm is the optimal choice. These tasks are complex enough to give you valuable experience, but not so complex that the project drags on for months.

At this stage, also think about:

Dimensions: the robot should fit on a workbench and be easy to transport
Power source: 7.4V LiPo batteries are a popular choice for mobile robots
Budget: component cost for a basic project can start from 5,000 RUB

Step 2: 3D Modeling of Parts

Once the concept is approved, you can start creating the 3D model. This is a key stage that determines how accurately and reliably all components will fit together.

Software choices:

TinkerCAD — ideal for beginners, browser-based, no installation required
Fusion 360 — professional tool with a free license for hobbyists
Onshape — cloud CAD solution, all work saved online
OpenSCAD — for those who prefer to program geometry

What needs to be modeled:

Chassis (base) — the platform on which all components will be mounted. It should have mounting points for motors, controller, and battery
Motor mounts — provide secure motor fixation
Document holders — for ultrasonic rangefinders, IR sensors, and other sensors
Protective enclosure — optional, for a more finished look

Important modeling principles:

Account for tolerances — fastener holes should be 0.2–0.3 mm larger than the nominal diameter
Add rounding in corners — they increase part strength
Provide technological holes for wires
Design with print direction in mind — minimize support structures

Step 3: Choosing Electronic Components

The “brain” and “muscles” of a robot are its electronics. Choosing the right components determines the stability of operation and ease of programming.

Main components for a typical project:

Component	Recommendation	Purpose
Controller	Arduino Uno / Nano	The robot’s main “brain”, processes sensor signals and controls motors
Motor driver	L298N or TB6612FNG	Controls the power delivered to motors
DC motors with gearbox	2 pcs, 12V	Provide wheel motion
Servos	MG90S or SG90	For rotary mechanisms and manipulators
Ultrasonic sensor	HC-SR04	Measures distance to obstacles (up to 4 m)
Line sensors	TCRT5000	For line-following motion
Batteries	Li-ion 18650 (2 pcs)	Provide autonomous power
Voltage converter	XL6009	Stabilizes power for the controller

Tip for beginners: buy a ready-made Arduino robotics starter kit — it already includes all necessary components and basic documentation.

Step 4: 3D Printing Parts

When the models are ready, you can start printing.

Material recommendations:

PLA — optimal choice for a first robot. Easy to print, eco-friendly, affordable. Ideal for enclosures and small parts
PETG — stronger and more flexible, better for parts under load
ABS — requires a heated bed and good ventilation, but yields strong, wear-resistant parts

Print settings for mechanical parts:

Layer height: 0.2 mm (balance between speed and quality)
Infill: 30–50% for enclosures, 70–100% for gears and loaded assemblies
Nozzle temperature: 200–210°C for PLA
Bed temperature: 50–60°C for PLA
Supports: enable only when overhang angle is more than 45°

Important: before printing, check each model for errors (intersecting surfaces, “holes” in the mesh) using the slicer. Make sure the part orientation on the platform is optimal — this will reduce supports and improve surface quality.

Step 5: Mechanical Assembly

After all parts are printed, the most critical stage begins — assembly.

Assembly order:

Part preparation: remove supports, sand contact surfaces with fine sandpaper
Motor installation: secure motors in their mounts with M3 screws. Make sure the shaft rotates freely without catching the body
Wheel mounting: fix wheels to motor shafts. Check concentricity
Mounting the control board: install Arduino and motor driver on the chassis. Use plastic standoffs for insulation from short circuits
Sensor mounting: secure ultrasonic sensor at the front of the robot. Place line sensors 1–2 cm from the surface

Tip: do a “dry” assembly first — connect all parts without screws to make sure everything fits correctly.

Step 6: Electrical Connections

Now you need to connect all components into a single electrical circuit.

Basic wiring scheme:

Motors → L298N driver: motors connect to OUT1/OUT2 and OUT3/OUT4 outputs of the driver
Driver → Arduino: IN1–IN4 pins of the driver connect to Arduino digital pins (e.g., D4–D7)
Ultrasonic sensor → Arduino: TRIG and ECHO connect to digital pins
Power: batteries → XL6009 converter → Arduino and driver

Important pitfalls based on real developer experience:

Reversed power polarity can burn out the voltage converter
Poor soldering of wires to motors is a common cause of failures
Mismatched communication channels between remote and robot lead to loss of control
Powering servos directly from Arduino pins can cause overload — use a separate power source

Recommendation: use a breadboard for preliminary testing of the circuit, and only after verification move the connections to a permanent base.

Step 7: Programming and Flashing

Once the “hardware” is assembled, it’s time to “bring it to life” with code.

Development environment: Arduino IDE — free, cross-platform, with a huge number of ready-made libraries.

Example algorithm for an obstacle-avoiding robot:

#include <NewPing.h>
#include <Servo.h>

#define TRIG_PIN 9
#define ECHO_PIN 10
#define MAX_DISTANCE 200

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);

void setup() {
  Serial.begin(9600);
  // Configure pins for motors
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
}

void loop() {
  int distance = sonar.ping_cm();
  
  if (distance > 0 && distance < 20) {
    // Obstacle closer than 20 cm — turn
    stopRobot();
    delay(500);
    turnLeft();
    delay(800);
  } else {
    // Free passage — move straight
    moveForward();
  }
}

void moveForward() {
  digitalWrite(4, HIGH);
  digitalWrite(5, LOW);
  digitalWrite(6, HIGH);
  digitalWrite(7, LOW);
}

Programming stages:

Install the necessary libraries through the Arduino IDE library manager
Write code starting from basic functions (forward/backward, turns)
Upload the sketch to the controller via USB cable
Gradually add new capabilities: line sensors, Bluetooth control, processing multiple sensors

Useful tip: use Serial.print() for debugging — output sensor values to the port monitor to verify correct operation.

Step 8: Testing and Debugging

The prototype is ready! But before celebrating, you need to run a series of tests.

Test scenario for a wheeled robot:

Check forward movement: the robot should not deviate to the side
Check turns: turning radius should be sufficient for maneuvering
Check sensor operation: ultrasonic sensor should stably detect obstacles at distances from 2 to 400 cm
Check autonomy: the robot should work for at least 30–40 minutes on a single charge

Typical problems and solutions:

Problem	Likely cause	Solution
Robot doesn’t move	Incorrect power connection	Check voltage on the driver
Motors twitch	Insufficient current from driver	Increase supply voltage or use external source
“Crooked” motion	Difference in motor speeds	Calibrate PWM signals for each motor
HC-SR04 sensor glitches	Interference from motors	Add capacitors to the sensor power lines

Conclusion: From Prototype to the Next Step

The path from idea to working prototype is a fascinating adventure combining several engineering disciplines. Even the simplest robot built by hand gives invaluable experience:

Understanding the basics of mechanics and 3D modeling
Skills in working with electronics and soldering
Practice in programming microcontrollers
Ability to debug and find faults

Building a robot on a 3D printer has democratized prototyping — you no longer need expensive machines or factory equipment to develop a new device. The experience gained is directly applicable in the professional world: from industrial robotics to building service robots.