Lightest motor for Sony-NEX gimbal
  • Hi,

    I'm new to this forum, and starting to design my first Brushless 2-Axis Gimbal using Alexmos BGC.
    My goal is to achieve a very lightweight gimbal, which can hold and stabilize a 500g camera (maiden tests will be conducted with Nex-7 w/ 18-55 lens). I'm currently looking for the lightest motors which could suit my needs.

    Theoretically, Alexmos says that almost no energy (and torque) is needed to stabilize a camera, so my question is: with a perfectly balanced gimbal, can I use undersized motors for Pitch and Roll stabilization ? If I could put the motors'weight down to less than 70g each, it would be great!

    Could you please give me some advice on how to choose the best (and lightest!) motor ?
    I would be very grateful if someone could give me an estimated value of the required torque to stabilize a Nex-7 camera.

    Thank you,
  • It depends a lot of your application. if an aerial gimbal, the motors need to hold the gimbal also when it is disturbed by airspeed and turbulence.
  • Thank you for your answer, Garug. And sorry for my lack of precision !
    You 're right, this gimbal is supposed to be put on a quadcopter, for aerial imaging. That is why I try to build it light !
  • Also, if the motor axis is not solid enough, you might need to add additional supporting bearings etc, so the lightest possible motor does not provide necessarily the lightest gimbal.

    Designing the gimbal to as small as possible helps a lot on all aspects, including weight.

    But sorry, I do not really have the answer, just things to consider.
  • Thank you for your help, Garug.
    By the way, my gimbal design will take into account the need of two solid/rigid pivot joints, independent of the motors internal joints. So, the two motors will only have to supply torque. All other forces will be handled by the gimbal mechanics.

    Just to add some details on my project: the gimbal frame will be made from hollow-moulded composite material. Only shafts and bearing seats will be made from machined aluminium.
    By design, the camera will have its CG perfectly placed on the Pitch and Roll Axis ( I aim to get a less than 1mm tolerance).
    This, combined to thorough mechanical tolerances, should give me the best stiffness/weight ratio.
  • How is your project going?