If you want to diy one quadcopter,have to choose all best parts for combination,how to choose motor for quadcopter is very important, If the thrust provided by the brushless motors are too little, the quadcopter will not respond well to your control, even has difficulties to take off. But if the thrust is too much, the quadcopter might become too agile and hard to control.
How to choose motor for quadcopter? This will include information on the RPM, thrust and power.The correct motor/prop combination needs to be chosen by considering the size and weight of the quadcopter, the length of flying time and the power and agility that are desired. Also, the battery and ECSs must be chosen to effectively drive the motor/prop combination. The question is focused more on the general characteristics of various combinations but some specific questions do spring to mind:
How many weight of your quadcopter?
When you’re estimating the final weight of your diy quadcopter, don’t forget to consider other aspects that may add to it such as weight of the propellers and motors as well. With regards to additional weight, it is important to consider the weight of the camera in case you plan on using your quadcopter for aerial or FPV photography.
A great formula of Thrust required is Required Thrust per motor = ( Weight x 2 ) / 4
For example, if you plan to accommodate 1kg of flying weight, by using the above formula, you will be able to looking for a total thrust of 2 KG and 500g per motor.A general rule is that you should be able to provide twice as much thrust than the weight of the quadcopter.As a general rule you want a 2:1 thrust/weight ratio for a standard quadcopter and 3:1 or higher for something acrobatic. 1.5:1 has been known to fly.
When selecting motors, there usually are specification that comes with the motor either provided by the seller or manufacturer. You should be able to find information about the power, thrust,rpm etc.
Consider Motor Efficiency before choosing motor
With less efficient motors not only are you wasting a lot of power, you also get smaller thrust on full throttle. Most important, because the motor runs so inefficient, the response time suffers. It will take the motors more time to change rpm and this will influence the stability of your quadcopter, and the quadcopter will be less stable.
Quality and brand is also important.You should research what other experienced pilots use and buy the same or similar equipment. Personally, I prefer this approach because it doesn’t require an understanding of the physics involved and I know the solution is proven.
Research and Learn from Youtube&Forums
There are a lots of videos about How to choose motor for quadcopter.you would research them on Youtube,We can start as suggested from other experienced pilots.On one hand,Go to experienced pilot’s websites or various forums they post in to find out what equipment they use and seek out any actionable suggestions from their comments.It takes much time and money to carry out test,but you can learn much more and very impressive.
Conclusion for choosing motor
A quadcopter doesn’t need high revving motors as there are 4 propellers providing thrust and high revving motors require more battery power.Generally you just choose a motor that matches the given prop. Having a motor that is too large will be heavy, and a motor that is too small will perform poorly or burn up.For mini quadcopter racing, you would want a very agile quadcopter, so having a much higher thrust to weight ratio is desirable, but for an aerial photography quadcopter that we will be flying gently, you could get away with lower power to weight ratios, but in general I would say that you should plan your build at around a 2:1 power to weight ratio, as you can always use the extra remaining weight to add bigger batteries to fly for longer.If you have some story about how to choose motor for quadcopter and want to share it,please leave your comments,Thank you!
Quadcopter frame and lipo battery and motor and propeller size matching table for your reference.