The Grizzly project was born out of the desire to expand my knowledge on Arduino programming and mechanical design. I decided to challenge myself to construct a tracked all-terrain vehicle that could be controlled using a smartphone´s accelerometer sensors.
Intuitive controls with smartphone accelerometer steering;
Steering, speed control and reverse
BLE 4.0 Bluetooth communication with up to 50m range;
8 Wheels Independent Suspension system;
Modular construction for easy removal of battery pack, motors and eletronics.
Arduino UNO Rev3
Adafruit Motor Shield v2.3
Adafruit Bluefruit LE shield
Inital components. During developing and testing over 800 spare parts were ordered.
The main challenge for the body constructions was implementing the fully independent suspension system. It was necessary to do a lot of research on actual tank suspension system, and I came across three main solutions:
Space efficient and very simple to build. Not truly independent as wheels must operate as a pair.
Torsion bar suspension;
Fully independent and simple to build. Not efficient at the build scale and very space consuming
Fully independent and space efficient. Requires a lot of parts.
I have decided to use the Christie suspension as it would provide the vehicle with the best mechanical suspension for the given scale.
It was necessary to fabricate custom springs and to miniaturize the levers so the assembly would take no extra space inside the chassis.
First fully functional model.
Had problems with motor speed and reduction factor, resulting in a fused axis;
Insufficient chassis stability, sapping the efficiency of the suspension system;
Low ride height, creating dificulties in overcoming obstacles;
Revised gearbox with compact frame
LED flares with automatic darkness detection;
Further increase frame strenght;
Increase track grip to allow for higher angle of attack;
Replace disposable batteries for a rechargable Li-Po pack;
Fine tune driving software.