MoVI Pro and magnetic fields

Discussion in 'MōVI Pro' started by Rick Gerard, Jul 24, 2019.

  1. Rick Gerard

    Rick Gerard Active Member

    Apr 22, 2017
    Likes Received:
    First, a little history. I've been mounting cameras on just about everything that moves for nearly 50 years. The crazier the better.

    I'm not completely thrilled with the suspension arms (Black Arm) out there for vehicle rigging. I've designed an what I think is a much better tension system using a principal I used about 20 years ago to mount cameras on a couple of Baja buggies. I won't go into detail but I will tell you that with a 30 to 40-pound load there are only about 8 ounces of force required to lift the payload up to the maximum or push it down to the maximum. The travel is 18". That's way less force than any other commercially available arm.

    With that little force holding center, a good shock absorber is critical or the arm will bounce forever. I've gone through about 10 different adjustable shocks and geometry, and they are all good, but when I install an eddy current brake as I did a long time ago, there is almost no rebound and the load stays pretty much on the same vertical plane when my car goes over bumps greatly reducing the parallax and perspective changes you get with a normal arm. The bounce and rebound are at least 10 to 15 times better than a shock absorber can deliver.

    Here's the problem. Eddy Current brakes work by moving a really strong magnet over a non-magnetic surface. To get this contraption to work correctly I have to introduce a very strong magnetic field about 10" away from the back of the MoVI Pro. I have not mounted the MoVI to the rig yet and before I do so I want to make sure I am not going to fry something.

    If anyone has any experience with strong magnetic fields and the MoVI I'd appreciate a heads up. Did not have to worry about it at all when I was shooting an Arri 35.
    Graham Futerfas likes this.

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