3D Printed Quadruped
Project Supervisor : Teo Shin Jen
This Instructable will show you how to build a quadruped robot from scratch using 3D printed parts and an Arduino UNO.
I was only a year one computer engineering student at Singapore Polytechnic that time when I was doing this small project. Having no prior knowledge of electronics or circuits, I met with many obstacles along the way. Hopefully after reading through my post, you would be able to learn from my mistakes and finally start your own projects. Currently as of writing this, I am already year two. I should have documented it earlier. now i try my best to recall and write it down.
Plans:
For the micro controller, I am using a Arduino Uno. For the servo moving the legs of the quadrupeds, SG90 9G Mirco Servo is used. Since this was my very first project, all the part were provide by my project supervisor. The idea for this project came from http://www.thingiverse.com/thing:343420.
Step 1: List of Materials
- 8 x SG90 9G Mirco Servo with the screws included
- 1 x Arduino Uno
- 1 x copper prototype board
- 3D printed parts that can be found
- 16 x M3 nuts
- 5 x 15mm long and 2mm wide screw, not exactly sure, i got mine from some screw shop. It is the same size as the SG90 9G servo mounting screw
​Step 2: Robot Construction
For the servo to slide into place, i had to disassemble each of them and put them in place. To disassemble the servo, remove the screws at the bottom holding the servo together. Then carefully remove the cover remember how each of the gear was position. Sometimes when the print job was bad, you will have to sand the edges to get the servo in place. After sliding the servo in place, assemble the servo as you disassembled. To secure the shoulder, I used 4 0.5 cm nuts. Each of the servo is secure by 0.5 cm screws that i brought from a screw shop. The hip and backbone is secured by a 1.5 cm deep screw while the rest is 0.5 cm deep screws. The body and the backbone is secured with a washer and a 1.5 cm deep screw.
Step 3: Circuit Design/Power Supply
For the circuit, it is pretty straightforward. Arduino Uno 5v and ground to each of the servos 5v and ground. Servo signal to each of the 8 Arduino I/O pins.. I have a external power supply that is connected to the Arduino Uno vin and ground pin respectively. For this project i did, i actually used a phone power bank to power the quadruped. In order to do this, I cut away some old micro USB cable and soldered the 5v and ground wire to a molex connector.
Step 4: Forward Movement Code
Depending on the circuit design, the servo will be attached to different pins. During my testing, I use the Arduino sweep example to test the range of movement for the quadruped. Download code here. You can edit the code with the value you tested from the sweep example.
You can also check out my simple blog here.