Center propeller and px4 configuration, need advice

Just started to plan for my next project and now i want to go some what advanced compared to my other projects.

I posted this over at rcgroup as well and got zero response so lets try over here.

The thing is that i read in a bunch of articles that large discs for elevation and smaller ones for “balance” can dramatically increase uptime.

One of the copters was a hexa where the stern and aft motor where really large and the 4 side motors had small propellers.

What i been thinking about is a copter with 6 motors. A hexa with two motors in the center with CW+CCW rotating propellers and have 4 motors in a standard quad setup for the actual flight control. The center should just provide lift and forward speed.

I seen some copters that are setup this way but the ones i found use an aux channel and a potentiometer on the tx to manually control the center propellers.

I would like my fc to handle that! The thing is that im lousy when it comes to manually change stuff in px4. I always use autotune.

I suspect the easiest way is to use a hexa plus setup in the px4 and move the front and rear motor to the center and change the motor output configuration (i already did this in my KK2 but in PX4 i am drawing a blank) so the center motors just provide throttle. And set the other motor percentage up as a standard quad.


Well its here i need some advice by a veteran in px4 and/or maybe someone that actually built a hexa with two center propellers.