4.7 KiB
title: quadrocopter date: 2019-06-20 author: Philipp Schönberger tags: bataflight, quadrocopter, fpv category: projects
Infected by the other members of the Toolbox e.V, especially Thomas I started to search for parts for a quad copter which could be used to race and do some freestyle moves.
Since for me also the assembly is new and I had the feeling that this quad will also be likely to be damaged I wanted to build it with separate components. Also its more fun that way.
Since I did not want to have a huge quad I wanted to hit the 250g Law limit for the assembly. In such a case I would not even be forces to add a burn resistant name tag to the quad, which I would anyway recommend if it could be lost.
After some search i found the Diatone quad frame GT M3 pretty appealing since they have a aluminum cage for the PCB stack and a 3mm carbon plate which is robust enough for a beginner.
[lightgallery /images/quad/diatone_130.jpg, Diatone 2018 GT M3 130mm Source: www.banggood.com lightgalleryend]
The following motors where selected by taking the recommendations of the frame into account: motorsize 1408 motorr 4000KV
The motor size of brush less motors for quad copters are regularly indicated by a 4-digit number The first two digits represent the stator width or diameter while the second ones represent the hight. The values types are in mm
In general the motor size have quite a influence of the flight characteristics. A taller motor most likely result in more power at the upper Throttle/RPM and a wider motor would result in a higher torque at low throttle.
Since I wanted to use motors with a actual data sheet or at least a test measurement how much thrust and amps would be drawn with certain types of propeller I did take a look at the T-Motor F20II F20 II 1408 3750KV
The where the ones which had a lot of thrust with XXXg when they are mounted with 3040 propeller types. T
[lightgallery /images/quad/motor.jpg, T-Motor F20II F20 II 1408 3750KV Source: www.banggood.com; /images/quad/motor_datasheet.jpg, T-Motor F20II F20 II dimensions Source: www.banggood.com; /images/quad/motor_datasheet2.jpg, T-Motor F20II F20 II electrical specification Source: www.banggood.com; /images/quad/motor_datasheet3.jpg, T-Motor F20II F20 II load specification with diferent propellor sizes Source: www.banggood.com; lightgalleryend]
At this point the Motors and Frame where clear. The next step was to choose a propeller type. For this I selected the three bladed one with close to the 3040 size. The only ones which are quite near to this are the Geprc 3042 The Number of the Propellers are also representing the size nearly as the motor identification number. The first two digits are the diameter in inch and the second two ones are representing the pitch of the propeller.
The Pitch is sometimes misunderstood to degrees of the propeller blade. The actual meaning of it is the forward movement of he propeller if it's rotating 360 degrees So in this case of a 3042 the diameter is 3 inch and the propeller is moving 4.2 inches forward in case it does one rotation.
You can imagine the higher the pitch is the more air is moved and the more thrust it should generate with the same rpm. Side effect of the higher pitch is a higher amp drawn thought.
part list: