CABLE CAM SYSTEMS FAQ
Technical FAQ: rigging point loads, AR protocols, positioning accuracy, and flight height
Technical FAQ for JoyMechanix cable cam systems: typical rigging-point loads and pulley force calculation, AR output (FreeD) with gimbal + lens data, positioning accuracy, and how cable sag impacts flight height.
What is the maximum camera speed?
The JM 2.3 Stadium System supports camera speeds of up to 10 m/s, which is more than sufficient for all professional sports and broadcast applications.
For larger JM 3.3 systems, speeds of up to 15 m/s are possible. These systems can be optimized according to project requirements, balancing speed and pulling force as needed.
For larger JM 3.3 systems, speeds of up to 15 m/s are possible. These systems can be optimized according to project requirements, balancing speed and pulling force as needed.
What force is applied to the rigging points?
Each system operates with different rope tension forces depending on the application.
For standard operation:
- Studio systems normally operate with up to 55 kg of rope tension.
- Stadium systems normally operate with up to 65 kg of rope tension.
- Industrial systems are custom-built according to the client’s requirements and may operate with significantly higher tensions than standard broadcast systems.
During rigging calculations, it is important to understand that each pulley receives force from two branches of the rope:
- one branch entering the pulley,
- and one branch exiting the pulley.
In some scenarios this may double the load applied to the pulley compared to the rope tension itself.
For this reason, all rigging calculations include substantial safety margins. The forces shown in our technical charts already include forces applied to the pulleys by two branches of the rope and an additional 3x safety factor for possible winch overpowering.
An additional safety factor should be added to the overall safety factor determined by the safety requirements of the country and the event location (if there are no special requirements in the country and the event location, a minimum safety factor of 3 should be calculated for the design for installation and operating loads).
This provides a high level of structural reliability for both permanent and temporary installations.
Which AR protocols are supported and how does the AR system work?
Our systems support FreeD protocol as well as several additional protocols compatible with industry-standard AR systems. However, the majority of clients operate using the FreeD protocol.
Our output signal combines:
- cable camera positional data,
- gimbal positioning data,
- lens zoom and focus information,
The system itself provides stable timing and synchronization for standard AR applications. However, for the highest level of frame synchronization accuracy, we recommend connecting an external synchronization signal such as Genlock directly to the control station.
This allows the AR output to achieve the best possible frame-accurate synchronization with the broadcast environment.
What positioning accuracy does the system achieve?
The system has undergone third-party testing and certification. During testing, the system completed multiple movements along a 1.5-kilometer trajectory and over 400 motion cycles. The positioning accuracy at any stage of the movement was only 1.5 mm!
This level of accuracy provides extremely high confidence in repeatable motion control operation.
How is the operational height of the system calculated?
For each project, it is important to calculate the operational flight height of the system in advance.
Since the payload is suspended on ropes, the ropes naturally create sag depending on:
- pulleys coordinates,
- payload weight,
- system type,
- and the position of the camera or payload inside the working zone.
Because of this, the available operational height changes depending on the system geometry and working area configuration.
To simplify this process, we provide a calculator that allows clients to estimate operational flight height. This chart provides a quick and practical way to understand the achievable operational area during project planning.
Do I need a generator for each winch, and what are the power requirements?
The system is designed to operate from multiple independent power sources. In many stadium installations, some winches are connected to stadium infrastructure while others are powered by generators. The control station may also be powered separately.
All communication lines are optically isolated, allowing different winches to operate from different generators without issues related to grounding or neutral potential differences.
The nominal power consumption of each winch is 7.5 kW under maximum load conditions. In normal operation, average consumption is typically around 4.5–5 kW per winch. While average system consumption is usually below 20 kW, we recommend providing a dedicated 32A, 400V connection for each winch to ensure adequate capacity under all operating conditions.
All communication lines are optically isolated, allowing different winches to operate from different generators without issues related to grounding or neutral potential differences.
The nominal power consumption of each winch is 7.5 kW under maximum load conditions. In normal operation, average consumption is typically around 4.5–5 kW per winch. While average system consumption is usually below 20 kW, we recommend providing a dedicated 32A, 400V connection for each winch to ensure adequate capacity under all operating conditions.
Can the system carry tally, talkback, return feeds, and AR infrastructure?
The standard system already includes 1G Ethernet, RS-232 communication and 12G-SDI video transmission between the camera platform and the control station. This infrastructure allows integration of tally, camera control, telemetry, lens data and other operational signals.
Additional signals such as talkback, genlock, return feeds and other custom requirements can be multiplexed into the fiber infrastructure if required. Our AR system normally provides fully processed tracking data, including camera position, gimbal position and lens information. If required, we can also provide raw tracking data for integration into third-party AR workflows.
Additional signals such as talkback, genlock, return feeds and other custom requirements can be multiplexed into the fiber infrastructure if required. Our AR system normally provides fully processed tracking data, including camera position, gimbal position and lens information. If required, we can also provide raw tracking data for integration into third-party AR workflows.
Does the video cable only support one 4K stream?
The standard system includes one 12G-SDI 4K video feed.
Quad-link 4K camera outputs are also supported, as four 3G-SDI streams fit within the available transmission bandwidth. Since the system uses fiber-optic transmission, additional video signals can be added if required through multiplexing equipment.
The standard Ethernet channel also provides up to 1 Gbps of connectivity and is commonly used for camera control, tally, telemetry, talkback and transmission of additional devices such as 360-cameras.