How to choose a gimbal motor

Gimbal motors are obviously a key element in any gimbal build. In fact - at least in the author's experience - the No. 1 factor which determines the performance of a gimbal is the choice of motors.

So, choosing the right motors is obviously important, but unfortunately it is not easy. On the one hand this is so because the range of different gimbal motor types which is available to us is very limited (and has in fact declined significantly in the last years). On the other hand the available gimbal motors are mostly constructed very badly and are - despite their name - far from ideal for the task.

So, what is a good gimbal motor?

The answer is somewhat lengthy and involves several aspects. A detailed account can be found in this article Brushless Gimbal Motors.

A short summary could be:

• The resistance should be in the range of 10 - 15 Ohm for NT setups, but smaller resistances are acceptable at lower voltage. For T-STorM32 setups the resistance would preferably be in the range of 4 - 10 Ohm, but higher resistances are also acceptable, and at lower voltage also smaller resistances.
• Low motor cogging is a most crucial factor, and motors with ferrite rings are much better in this regard and should be chosen whenever possible.
• Friction is disastrous and should be as low as possible. Motors with substantial friction are not worth the time.
• The inductance of the motor coils should be as small as possible, but we rarely can do anything about it.