Bottom plate is now fully wired.
Each arm is connected with 2 short screw and 2 long ones, the short ones go through one 5mm spacer and the long ones point upwards with a 5mm on the bottom and another on the top with an m3 nut to hold them in place.
This means that the bottom plate is a sub assembly and can be taken off the quad to be worked on if needs be.
At the front is a small 6 way black connector and there is a small plug in wire harness to connect to the flight controller on the 2nd plate.
Just waiting for some more 5mm spacers to finish of the last arm and then the bottom can be mated to the top and the flight controller wired before first testing.