Introduction: Raspberry Pi Hexapod Wooden Robot.
Robots in education have became an important tools to enhance students skills in mathematics, computing, imagination, thinking, creativity and productivity. The education system in Egypt suffers from some chronic problems, including the lack of practical educational methods, the lack of continuous modernization, and the lack of financial resources to activate these practical curricula. Where the process of education is limited to the theoritical way and this does not achieve the required development needed.
I was a laboratory technician at Egypt - Japan University of Science and Technology (E-JUST) (Mechatronics and Robotics Department). I was responsible for laboratory-based tasks and for providing all the required technical support for faculty members, researchers and students to operate advanced Mechatronics devices and Robots effectively whilst adhering to proper procedures and safety guidelines.
I participated in the training program in Japan (Practical Technology for Mechatronics and Robotics). The program is designed for educational institutions to enhance teacher’s teaching skills of practical technology for Mechatronics and Robotics in order to satisfy the demand of industries.
After I returned to my country Egypt, I started to make good definition of the optimal use of Machines and Robots and eliminated the lack of experiences in the use of devices for future developments in my Department. In particular, I achieved the following:
1- Equipment Guidelines Instructions Book https://goo.gl/cK5Piv for the optimal use of research equipment at the Department of Mechatronics and Robotics; which describes optimal usage of 29 devices - rules, rights and responsibilities of users into laboratory –Laboratory safety in 56 pages.
2- Organized, coordinated and built curriculum for Educational robots for undergraduate students. The experiment book https://goo.gl/kj9uo6 aims at facilitating the practical applications of important concepts of Mechatronics. To describing key educational experiments such as a mobile robot made from foldable structure, two-digit display unit, ultrasonic sensing, servo control, simple mechanical hand and legged locomotion (hexapod).
The idea: The method for practical education in Egypt considering low-cost materials.
Experiment Book name: Learn how to build a robot from scratch.
♤ Description: The proposed method for practical education in Egypt considering low cost material consists of the following ideas:
• A portfolio with novel curriculum of hands-on practices in the form of “experiment books”, focused on basic programming, mathematics, imagination, thinking, creativity, and productivity skills. The overall goal of the portfolio is designed so that students focus on achievement by designing, developing and manufacturing things.
• The portfolio considers low cost materials and components, which is very important for most educational centres in Egypt.
• Lectures in active learning style combining the latest educational trends in the world, where interaction and coaching between instructor and student is maximized.
•Evaluation of activities in education is focused on the achievement of experiments in the portfolio, which is related to connecting theory to practice and enhancing the imagination of students.
♧ In particular, the experiment books aim to:
▪ Facilitate the implementation of practical experiments to clarify the important concepts in engineering field.
▪ Include the practical activities of the useful examples of newly constructed educational experiments,
▪ Include the design, manufacturing, assembly and programming of educational robots from scratch and some electronic circuits related to engineering field.
▪ Includes useful exercises for the student to enable self-learning through the implementation of experiments.
▪ Helps student to develop imagination skills by learning how to create and build new circuits and teach them how to build the new engineering mechanisms from scratch using low-cost materials.
I graduate from Italian technical school DON BOSCO in Alexandria, the best time ever I had when I were in workshop to gain the practical lessons, learning by doing is an interesting method to gain a skilled workers.
Let's start ------->
Definition of the hexapod robot:
A hexapod robot is a mechanical vehicle platform that walks on six legs, each leg have three servomotors 3DOF three degree of freedom, the purpose is to build the robot from scratch by imagining the designing structure of the hexapod and manufacturing the body structure using very simple tools and low cost materials.
1- Servomotors SG92R (18 units).
2- Raspberry pi 2 model B.(1 unit).
3- Sheet of wood MDF 4mm. (1 unit).
4- Wires (male-female, male-male).
5- Metal wires diameter 7mm. (2 Meter).
6- Adapter 5V. (1 unit).
Step 1: Introduction of Basic Components.
Servo Motor: A servomotor is a rotary actuator or linear actuator
that allows for precise control of angular or linear position, velocity
and acceleration. It consists of a suitable motor coupled to a sensor
for position feedback. It also requires a relatively sophisticated con-
troller, often a dedicated module designed specifically for use with
2- Raspberry Pi: is a small PC integrated in the palm size of the
hand low-cost and less energy consumption, "less than 3 watts."
It was designed at Cambridge University to help teach computer
science students and capable to integrates between Linux systems and
knowledge of programming and electronics systems, smart control
at the same time, making this small computer achieves a stunning
success in both educational and practical projects. The Raspberry Pi
is contained on a single circuit board and features ports for (HDMI -
USB 2.0 - Composite video - Analog audio - Power - Internet - SD
3- Wires: are made from metal, it using to flow the electricity. Please
Take care when you connect wires in circuit to avoid the short circuits
maybe happen. In this circuit we need to use two type of wires
(male-male wires and male-female wires).
4- Sheet of MDF: are made from wood, In the start to achieve the
structure of robot I preferred to choose this soft kind of wood to be
easy to cutting and forming it, The kind of MDF thickness 4mm is
good to start this project by using very simple tools.
5- Metal wire: are made from metal with thickens 0.7mm, the wire
using for link between the servo and the joint made from MDF, after
calculating the distance between the servo and the joint you should
cut and folding from the parties as shown in the picture.
Step 2: Basic Tools.
You need to use some basic tools to cutting and folding the MDF sheet. Some tools to connect the electrical connections and some measurements tools.
Step 3: The Structure of Hexapod Robot.
The hexapod robot is based on mobile (walking) robots principles. The structure is divided for two parts: Mechanical design and electrical design.
♧ The mechanical design is divided in two stages:
• The mechanical structure of the robot body includes the base parts of the hexapod and the six legs , each leg have 3 servo motors to facilitate the movement,
• The six legs are moving by 18 servo motors the controller of the robot is Raspberry Pi 2 Model B (the brain).
■ The first try to make a hexapod robot as shown above.
Step 4: Design and Cutting the Structure Body.
Start to design the structure body of the hexapod by imagining how is the robot shape should be, in this project I started to design by own self as shown in the above pictures. Then, start to cutting the MDF sheet depend on the dimensions you designed for the body and the legs using the soft cutting tool.
Step 5: Installation: Fix the Servos
Start to fixing the 18 servo motors and link them with the joints by using the metal wire after measuring the actual distance between both.
Step 6: Kaizen Concept.
♧ Definition: Kaizen Japanese concept is the practice of continuous improvement, that mean taking small actions for the continue development to achieve big achievments. One of the most notable features of kaizen is that big results come from many small changes accumulated over time. This concept has been misunderstood to mean that kaizen equals just small changes.
♧ Question: What is the importance of Kaizen in our work?
To build your robot system, the results come after you start to divide your actions with continuous improvement, that mean everyday with modifying small things new to the system the achievements will be big. Let's continue ------->
Step 7: The Electronic Circuit.
♧ To build the electronic circuit, we should prepare the following:
1- 18 Servo Motors + Raspberry Pi2 Model B + Source power 5 V. + PC or Laptop + HDMI cable + Display + USB
cable + Wires (male-male, male-female)
2- Connect the Servo motor as follows:
• GND from the servo with GND (Pin 6) in Raspberry Pi2 Model B.
• Pulse from the servo with GPIO 14 (Pin 8) in Raspberry Pi2 Model B.
• Power from the servo with +5V (Pin 4) in Raspberry Pi2 Model B.
■ The Electrical design is the connection between servos, Raspberry Pi2 Model B and the power source, it uses to moving the hexapod robot system depend on the programming codes you make.
Step 8: First Time Using Raspberry PI.
♢ For the first time using the Raspberry Pi, please following the next
1- Start to download NOOBS offline and network install software from
Raspberry Pi website.
2- Format the SD micro memory card (Should be not less than 4 GB) by
using SDFormatter V4.0 and change the settings as follows:
• Change the volume label to FAT.
• Change the option of the FORMAT SIZE ADJUSTMENT to ON for making better formatting to the SD card.
3- Upload the NOOBS installer on SD micro memory and connect the
Raspberry Pi as follows:
• Connect the mouse and the keyboard to USB port in Raspberry Pi.
• Connect the network cable in router to the LAN port in Raspberry Pi.
• Connect the HDMI cable from HDMI port in Raspberry Pi to the display.
• Connect the Raspberry Pi with micro USB power supply +5.1V (RPI doesn’t have an "On/Off" switch).
4- Start to setup NOOBS by selecting Raspian, the setup will take several
Step 9: The Pins Ordering in Rasspberry PI 2 B+
● The above photo, the student should learn about the Pins ordering
in Rasspberry Pi2 B+.
● Students should know about the difference between the numbers of
GPIO and the Pins ordering on Raspberry Pi board when starting to connect it with servos.
Step 10: Exercises:
Exercise1: Motion Primitives - Starting LXTerminal
□ The terminal or command line on a computer allows a user a great deal of control over their system (or in this case, Pi!). Users of Windows may already know it by several names (Command Prompt or Powershell), users of Mac OS may be familiar with Terminal. These tools allow a students to directly manipulate their systems through the use of commands. These commands can be chained together and/or combined together into complex scripts.
□ On the Raspberry Pi (running Raspbian), the default termina application is LXTerminal. This is known as a ’terminal emulator’,
The application can be found on the Raspberry Pi desktop and when started will look something like the above photo.
Exercise2: Control Servomotor by Using Raspberry PI.
import RPi.GPIO as GPIO
pwm.ChangeDutycycle(2) % the servo is moving now
pwm.ChangeDutycycle(4) % Now change the value and the
servo continue to move.
pwm.ChangeDutycycle(7) % another value
Exercise: Moving the Servomotor by Change the Value of Angel Positions
import RPi.GPIO as GPIO
for i in range(0,20):
desiredPosition=input("where do you want the servo? 0-180 "
Step 11: A Quick Overview of the Training Course in Japan.
♧ The training course (Practical Technology for Mechatronics and Robotics) was held in cooperation between JICA Kyushu (KIC) and Kitakyushu International Techno-Cooperative Association (KITA). The Training program helped me to better understand Mechatronics systems.
In particular, the most beneficial lesson I learned are as follows:
1- The Fundamental lectures in Control Engineering, Information Technology, Electronics, Electrical Engineering, and Mechanical Engineering.
2- The Practices and experiments to build circuits using PIC, simulation technology, computer control, AC variable speed motor control in JICA laboratories and in Japanese companies and laboratories.
3- To understand Japanese practices and industries in real situations by visiting technical high schools and factories (for example Yaskawa – Daifuku – Nissan – Mitsubishi Electric co. – Shinnippon Non Destructive Inspection co. – SMC Co. - Tokyo Denki University – Kyushu Institute of Technology) to learn more about industrial robot control, injection modeling machines and machine tools.
♧ By participating in this training course in Japan, I reinforced a number of important skills needed for good management of work, such as organization skills, planning skills, technical skills and communication skills. Also, I reinforced self-improvement skills to develop new educational robots and to interact with the surrounding community (schools, universities).
I would thank the Japanese professors and coordinators of this course for the big effort and support to teach and care about me when I were in Japan.
I was thrilled of having this unique opportunity and honor to be a participant of this course.
Also I would like to express my sincere gratitude to JICA, KITA, Japanese Government and Japanese People to provide this important training course. I deeply appreciate all the support I have got throughout the three month training time.
Participated in the
Raspberry Pi Contest 2020
3 years ago
Its the Isper! Ispider spIder! dangit.
3 years ago
It is a bit misleading to say you only need a RPi to power servos.
If someone connects even one they might cook their RPi.
How about telling us what all the wires go to?
Reply 3 years ago
Thank you for your comment.
Step 8 explain how to connect one servomotor with rpi as example, this can guide you to connect 18 servomotors with rpi, Rpi have enough gpio.
Step 13 explain how to program one servo by using python programming, its very easy to use and you will enjoy to do it by your self.
This instructables aims to show this educational method to the young generations to encourage them to think, immagin and create.
Learning by doing is an important concept and applied method in education in developed countries, where the interaction between professor and students is very useful.
3 years ago on Step 9