Drives & Controls September 2022

A LOS ANGELES COMPANY that develops equipment for the film industry has used a motor with a stator formed from a PCB (printed circuit board) to solve a problem with hand-wheel systems that are used to operate cameras remotely. Cinematographer Boyd Hobbs founded the company, Nodo Film Systems, in 2018 with the aim of creating smarter film-making equipment. The following year, he launched his Inertial Wheels controls which introduced simulated inertia to hand wheels for camera operators, allowing them to operate cameras remotely and to obtain haptic feedback as they worked. However, Hobbs faced a problem in achieving this feedback. With conventional motors, as torque increases, so does the cogging effect. Although there are specialised brushless motors that overcome cogging, they can be expensive. So he turned to Massachusetts-based E-Circuit Motors (ECM) which makes motors with PCB stators which, it claims, eliminate cogging. Nodo designed a custom wheel assembly that integrates a PCB motor with a hand wheel to create a direct-drive mechanism. Using duplex wireless connections, the system can operate cameras remotely up to 1.6km away. With a hard-wired connection, the range is around 600m. The new inertial wheels generate three times more peak motor torque than the previous version, while using the slotless motors are able to achieve realistic feedback beyond the weight of mechanical gearheads. The PCB Stator motors also cost much less than cogging-free brushless motors. The motors stabilise and smooth the wheel movements. The “weightiness” of the wheels can be adjusted to suit the shot, or be switched mid-shot using presets. When the camera stops at a limit, so do the wheels. The operator can feel when a limit is hit, with the motor bringing the wheel to a stop precisely where the camera is. Nodo plans to sell its Inertia Wheels Max controllers in two- and three-axis versions. “The result of this collaboration is a major step forward for both the film industry and high-torque, high-precision haptics,”says Hobbs. “The combination of torque, precision, flexible form factor, and ease of manufacturing did not exist before these motors. It’s an inspiring and revolutionary combination of technology.” Nodo is working on other products that use the PCB stator motors. It also plans to offer integration, motor/driver design and firmware development services to other companies in the film industry, as well as those from other sectors wanting to develop haptics-based products. https://pcbstator.com TECHNOLOGY n Cogging-free PCB motor helps to control film cameras remotely with haptic feedback Nodo’s InertiaWheels Max controllers allow camera operators to control cameras up to 1.6km away and to receive haptic feedback via the handwheels (above). An exploded view of the handwheel controller incorporating the PCB-stator motor (right).