A Stewart platform is a type of parallel robot that incorporates 6 prismatic actuators, typically hydraulic jacks. According to Wikipedia, the actuators are mounted in pairs to the mechanism’s base, crossing over to three mounting points on a top plate.
Meaning, devices placed on the top plate are granted 6 degrees of freedom in which it is possible for a freely-suspended body to move. These are the three linear movements x, y, z (lateral, longitudinal and vertical) – and the three rotations pitch, roll, & yaw.
The project – which can be found on Instructables – is designed to accommodate a DSLR as well as other digital cameras.
“This version of Stewart Platform use ordinary hobbyist servos instead of linear actuators for motion,” ThomasKNR explained.
“The whole platform is controlled by an Arduino Uno, [which] computes all necessary equations to get the platform into right position and also controls servos.”
Key platform features include:
- Supports loads up to 2kg.
- Low power consumption (around 5W).
- Capable of precise movements (within approximately 1mm).
- Can repeatedly achieve the same positions.
- Stable – even with a heavy load.
All told, ThomasKNR says the total BoM for his rotary stewart platform likely equals around $150 and includes a base PCB, acrylic, an IrDA unit, cables, servo arms, spacer screws and an LCD with I2C interface.
So, how does it work? Well, according to ThomasKNR: “The controlling platform uses inverse kinematics. We know the position of the base and the desired position of platform – calculating the necessary rotation of servos.”
Interested in learning more? You can check out the project’s official Instructables page here.