Which Motors do I need?
  • Hello,

    I am working for a german company who is developing and selling gyrocopters. I am going to develop a gimbal out of aluminium profiles for our gyrocopter. I want to use the Simple BGC 32 Bit controller and now I don't know exactly how to choose the right motors. Maybe someone can tell me what I have to consider when choosing the motors.
    The camera will be a thermal camera with a weight about 1.5 kg. While I am using the aluminium profiles because I just dont want to clamp these typical carbon fiber tubes together. In case some of the clamps loose while flight the expensive camera could fall off. So I choose the aluminium profiles to screw them together. I think this will be much safer. But in the end the weight is higher so I guess I need stronger motors. Anyone have some advice for me? I am just in the beginning of developing so any advice would be great!

  • hello,
    Glad you Brut this up ! your totally incorrect clamps do not loosen for them self and are easy to replace carbon fiber tubes are easy to replace , than a new custom aluminum part. In terms of camera if you looking at mirror less camera you need GB4114 motor small DSLR GH3 to 5D mark II, GB5802. now with new encoders you may want to look at these only ones with encoders built in .


  • If your manufacture this is probably don`t care but from a user perceptive I would never buy a all aluminum gimbal!
  • Why not? aluminum is excellent for gimbals.
  • First of all thank you for the tip.

    Maybe your right, that clamps won't loose but in case that in aerospace there are some rules and saftey issues that I have to think of I thought it would be better to go with aluminium profiles like these: http://product.item24.de/produkte/produktkatalog/products/konstruktionsprofile-5.html
    After all the camera is expensive and it would be aweful if it gets loose. And if it would fall off parts could get into our pusher propeller so this is the reason why every screw on the gyrocopter has to be secured with wire or has to be assembled with self securing nuts.

    You can assemble these profiles easily while clamping them with special connection parts plus you could assemble extra safety screws so it can not fall off when it gets loose. I think the weight with 0.5 kg/m for 20x20 profiles is acceptable, don't you think? I don't know exactly what the weight of the whole gimbal will be. I just wanted to understand how you choose a motor. I can't find a torque value in the details of the motor. So how would you see that the motor is right for your gimbal if you know what the weight is and how long the levers are? I think I have to know how fast the rotation (e.g. 50°/s or something like this) should be, should't I?

    Can you give me an explanation how you choose your motors? Would make it easier to me to explain my decision to other people. :-)
  • I am not though convinced about using aluminum profile, the joints must be really good and exactly 90 degrees. CNC machined aluminum pars would be much better.

    Choose bigger motors that you think you will need. You can always tune the power down on too big motors, and actually you do not need to, it is better to have much power.

    If you use encoders, smaller motors can be used, because they will not overheat easily as they will do without encoders.

    If there is much airspeed, then the gimbal needs to be compact and motors strong.

    So there is many things that will affect. what motors to choose. my only advise is choose big ones. For next version you can then try smaller and less expensive motors. Choose operating voltage according to motor resistance. Higher voltage also provides more speed when the motor is the same. on th e other hand less resistance typically provides more speed with less voltage.
  • my gripe about aluminum is custom parts are too expensive to replace after a crash. it is strong durable material but aluminum still can breake when they do repace the hole thing.
  • I thought the operating voltage is given by the controller?
  • Yes BGC controller has a max operating voltage 32bit 6s 22v. The motor power ultimately determines the voltage. Motor needs power enough not to slip when tilted in extreme angels, motors should not getting too hot. Higher voltage controller work best with large gimbals.