Maxwell Stoughton
M|S
System Overview
This Object Tracking Stepper Motor Pan-Tilt system was designed for lightweight machine learning experiments. It features a 12MP camera, 3 high-fidelity 6-wire slip rings, an RPi 4B, and two NEMA 23 stepper motors.
The system consists mainly of 3D-printed components with heat-threaded inserts, and large structural elements were laser-cut. Due to the high tolerance requirements, several prototypes were needed to achieve optimal performance.
Interactive System Head Model | Fusion 306
Design Process
The unique slip ring design enables 360-degree freedom of movement for both the pan and tilt axes. The NEMA 23 stepper motors provide sufficient torque and speed, even when microstepped.
To meet the varying voltage and amperage demands, a custom 700W power unit was developed to convert 120V AC to a variety of required voltages. Safety measures in the PSU include thermistors, fans, fuses, and an emergency stop (E-Stop).
The machine pans using two metal plates and a large bearing to transfer mechanical load away from the motor coupling. Electric power is transmitted from the PSU through one of the three slip rings across the pan axis.
Power delivered through the bottom slip ring is passed upwards along the tilt gantry and the remaining two electrical feedthroughs, preserving the system’s full range of spherical coordinate motion without angular limitations.
Once power reaches the head of the machine, the Rpi 4b sends serial commands backwards through the feedthroughs and gantry to two industrial size A4988 motor drivers. Tilt is then drven across a large gantry and timing belt. This belt is manually tensionable via an idler pulley at the base.
Though there is still much work to be done with this experiment, It has overcome many advanced electromechanical design hurdles laying a sturdy foundation for future design iterations.
Featured Photos
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