Mantis X8 Frame Assembly
Follow the non-existent instructions contained in the kit to assemble. Take care with the tube clamps - they only mate properly in one orientation. If you accidentally flip one of the half-circles, you could crack the carbon fiber tube if they don't properly align. Do not attach the propellors yet. This will be the last thing you attach only just before you are ready to fly.
In an attempt to keep RF noise away from the sensitive electronics, I decided to mount the ESC's near the motors. First, I assembled a power wire harness to provide a Deans connector at the end of each spoke as seen lying below the frame below:
Next since the PWM wires were not long enough I decided to replace with shielded coax to further reduce RF noise on the platform. RG196AU is a nice small diameter, reasonably flexible coax which was easy enough to crimp onto a servo connector:
Now is a good time to test all your ESC's and motors and determine the wiring to ensure proper rotation. I used a cheap servo tester to allow me to test each motor independently. Well worth the $5 investment. It is also recommended that you use a power supply with a current limiting feature for the first poweron instead of the battery in case there is a faulty component. Once direction is established, mark the four that need to be reversed and swap two of the three motor wires (any two will do). Use the diagram on the multicopters page for the motor identification and rotation. To help me remember which way each motor rotates, I just remember the the two in front are rotating such that any leaves, branches, or fingers that get cut off by the blades are thrown away from the hub. The motor numbering is odd - I cannot think of any rhyme or reason for the order, but these are the numbers of the servo port to connect them to. Wire labels on the servo connectors might be useful.
To help hold the ESC in place and manage the wires, I designed a custom fixture. Once assembled, each motor&ESC looks like this:
I've had difficulties in the past with electronics interfering with GPS lock so I mounted the PX4IO on the bottom of a copper clad PCB (grounded) to hopefully shield the GPS which mounts on top. Took a little concentration (and a protractor) to get the mounting holes in the right place such that the FMU would be pointing forward with an X configuration.
Installed with GPS and EzUHF RX:
note: GPS was later moved to one of the arms to reduce interference