Here are some more details on those things that I have more information on.
F450 Frame Dimension
But since you are using a 4in1 ESC you will not need to use any of those solder points as the 4in1 ESC has all of those things built in.
As for the brush-less motors, it does not matter what order you connect them, you only need to swap two of the wires if you find that it is rotating the wrong way around. That is probably why you could not find much information about the connectors.
Lastly in terms of setting up pixhawk and connecting everything to it, I suggest you have a look at the manual here
If you do have any questions about something just let me know and I will try to help.
Motors, yes I knew you could swap the leads to reverse them, I just didn’t want to be plugging the control wire (if thats the correct term) into the positive or negative connector of the ESC. Dont know if that would cause damage, but hard to identify as no markings anywhere (or colours) that I could detect, so thanks for clarifying.
Sorry about the delays in getting back to you about this, for some reason I was not notified via email.
To connect the ESC to your flight controller you will see 4 wires, 1 of them will have 3 cables, and the others will have a 3pin connector but only one of them are being used. On the actual ESC you will see some labels for each of the wires.
S1 wire (brown) connects to ESC 1 / Motor 1
S2 wire (red) connects to ESC 2 / Motor 2
S3 wire (orange) connects to ESC 3 / Motor 3
S4 wire (3 wires, black, red, white) connects to ESC 4 / Motor 4 where the wite wire is the signal, red is 5V output and the black is ground.
In that case it does not really matter as brushless motors dont have , , and a signal wire. With brushless motors, each wire goes to a set of coils inside the motor and the ESC sends power at precise timing to each set of coils to cause the motor to spin. An example is shown below but ignore the to Battery writing as that should be to ESC in our case.
So when connecting the wires to your motor it does not really matter, but if you find that the motor is spinning in the wrong direction you just need to swap any of the 2 wires to change the spin direction.