2014-09-21

DIY drone - tutorial for developers | Part 5 - Assembling the power components

Here is an overview of what we gonna need to do:


The convention is always the same to avoid shorting cable:  anything with live power is female, everything slave of those is male.

From the bottom to up :

  1. the battery (female) will be hooked to the main power bus (male)
  2. the power bus will be split in parallel in 4 other connectors like the battery had (female) and hooked to the ESC (male)
  3. The ESCs doubles as BECs so have 3 functions :
    - the first one is to take this power (male connectors) and modulate it in a way that drives the brushless motors through the 3 motor connectors (female)
    - the second one is to transform this 12v power to 5v and output it on the small female connectors
    - the third one is to interpret the amplitude from the third signal pin of those small 3-pin female connector (here it is white) and apply it to the motors 


Here is my intermediate step for the power bus :


I used the inside of those household connectors to do that :

Then I soldered those 2 by 2 : 2 blacks with 2 blacks, 2 reds with 2 reds.

And soldered the input from the battery on top of them (you'll need to heat the thing quite high to be sure it is correctly soldered).

Some shaterton to secure each side, soldered the connectors and added the shrink tubing.

Tip to solder those connectors : holding them with the pliers, fill them up first then reheat them up and plug the wire in and wait a bit that the melted metal goes it the wire by capilarity.
  

Same thing for the connectors on the ESCs, on the power side male connectors, on the motor side female.
You might wonder why the 3 wires on the motor side are all red. It is because they are basically all the same. The order of their connections to the motor will only determine if the motor will turn clockwise or counter clockwise.

Jargon : CW = clockwise CCW = counter clockwise.