Mike Johnson

"Window", being deadband, is not an issue for our system. We have a 'zero' button that allows the wheels to be offset to the zero reading of the rc transmitter being used, so the Movi window will not need additional adjustment. As for speed control, we have a sensitivity knob on each wheel that scales the wheel output. If used with a movi, then the movi software setting would be in tandem, but I just set the movi full speed and adjust on the wheels. As for damping, we offer none except the additional mass of the internal counter weights. My experience with the Movi and its gyro feedback, coupled with the RC radio latency of the transmitter, additional damping is not particularly desirable. The remote movi interface be it via RC joystick or with any wheels plugging into an RC transmitter is not super tightly coupled. So adding extra de coupling to soften the wheel response is not necessary. Also consider that the Movi will top out in the 35-50mm lens range and dampening is a feature of long len work....

I understand your question. In order to maintain exact wheel to head motion relationships, there needs to be direct feed back on the head. High end equipment like a Libra head have stiff drive trains and position feedback generated by encoders or resolvers mounted that is accurate to the movement of the camera. As a result they can be expected to track a tight relationship between movement of the hand wheel and movement of the camera. In the case of the jimmy jib there is no feedback at all. The amps are tuned to move by some arbitrary ratio of the hand wheels. However if there is slippage, or imbalance in the load due to camera CofG or wind or any other external effect, then the camera moves differently. The controller has no idea where the camera position is or how fast or far it is moving. THis design works because there is a torque limiting clutch in each axis. There can never me precise control in an open loop control system. In the case of the Movi and other gimbals, there is no direct camera axis postion feedback. Camera position is not controlled by encoders mounted on the camera axis. Instead it is generated by a three axis gyro. This provides velocity and acceleration information but not position. These gimbals work to control camera velocity, but they have only the earth gravity reference of the sensor. This is used to control horizon, but there is no information generated that can allow the system to track position in the way you describe. The same is true of a PowerPod which uses Tacho generator voltages as feed back. In that case the controller knows only how fast the axis is moving and not where it is. If you want a precise wheel to camera axis relationship to be maintained, then you must look to a system that uses a closed loop servo system with encoder or resolver feed back directly mounted in the individual axis drive train of the head. This makes for a higher cost and heavier system then the movi style gimbal or the jimmy jib, but the digital controls and the stiff drive trains that are typical of higher end camera mounts allow them to provide that exact precision coupling between wheel and camera that you mention..... I hope that helps

There is no question that an encoder to RC interface can be made cheaper and still sort of work. Arduino and plywood are your friends if that is the road you are travelling. When I was doing the mechanical design of the Veracity wheels, I opted for precision and ruggedness over ultimate cheapness. By having hand wheels CNC machined instead of off the shelf Milling machine wheels does increase the cost, but provides a better feel and familiarity to operators used to heads like Libra or Scorpio. Adding in adjustable balance counterweights also adds to the cost, but allows perfect balance every time, as well as a 'feel' of inertial mass that allows the wheels to better mimic a traditional geared head. I think it is important to remember that there are plenty of gimbal operators out there that will find the RC joystick to be perfectly acceptable for operating. But for operators who want to retain creative control over gimbal shots and who do not not find the RC joystick suitable, then the feel and quality of the interface should not be discounted. it is after all the point of sale terminal, so as to speak...;) That was the design philosophy that I embraced when I made a lot of the decisions regarding the Veracity wheels.

Hello. Mike Johnson here, co designer of the veracity wheels. Our system creates a digital data stream that is read by RC transmitter. The RC transmitter (such as a Spectrum8 that ships with the MOVI) can be configured to substitute the joystick signals with the digital stream that our wheels create. This is connected in the RC trainer port. The accuracy and feedback of the gimbal rig is not affected by the wheels. The gimbals are typically as accurate as the sensor modules they use. Another factor is system latency. Different RC transmitters have different latencies. Some as low as 10ms, but many much higher. Our wheels add no latency to the system as all the processing happens inside the single data package heartbeat time frame. The jimmy jib as I know it (aka Staunton triangle jib has no feedback whatsoever. It runs open loop and uses a slip clutch to mechanically limit damage. This is makes it low cost at a sacrifice for motion quality