I've built a basic, little and mobil robot, simple but resistant, able to move easily through many surfaces with precision.
The robot is a resistant and easy to build chassis made of "Actobotics" aluminium channels. Thanks to these channels we can get a great robustness and a reduced weight. I choose six wheels using six motors that give them a great traction. The movement is done by two groups of three motors. The three motors in each group move at the same time. One group in the right side and another in the left side. They give the robot a tank like movement that greatly simplifies the traction.
Great wheels give it the off-road features and the shock absorption/cushioning capability of this kind of vehicles.
The brain of everything is an Arduino board that controls all the electrical part, with a great power and able to control the extensions that may be added in the future.
The remote control is implemented using Xbee modules that are easy to use, providing a great security and a long range more than enough for a possible future experience of driving by watching its front video, FPV.
Overall dimensions of the robot: 42 cm length, 32 width and 12.5 height.
Weight: 3,430 kg.
Speed depends on the motors. For my proposed 100:1 gear reduction, it reaches 0.7 m/s (2.4 km/hour). If you decrease the gear reduction, the speed will increase while decreasing traction. The opposite if you increase the reduction: slow speed but increased traction. In the videos you can see the off-road capabilities, depending greatly on the type of surface you are in, the wheels are highly suitable for steep slopes for their great traction.
The LED lights have polarity, so if they are not properly connected they will not work. You will need to reverse the connections.
A wheel may turn in the opposite direction. To fix it, just reverse the wires that feed the motor.
If the whole group of three motors rotates in the opposite direction, just reverse the connections of the group in the driver “Sabertooth”.
If the problem is that the turns work opposite as expected, the easiest fix is to exchange the pairs of power cables in the driver “Sabertooth”.
The driver Sabertooth has a voltage sensor for the lithium battery, which protects it from excessively low values that would turn it useless. Because of that, if it’s working well and at some point it stops, test the voltage of the battery and recharge it if necessary.
As next improvements I have set myself two goals:
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