VTOL motor mix

[Scottyh72]

I have a vtol setup. I need help with the motor mixer for the transition. In the doc it shows a motor mixer with 5 motors with one being a weird -1.5 value. If I use this, esc's won't arm. If I go to the standard tricopter motor mix, the aircraft hovers fine. It will go to the 45 degree transition fine. But the tranisition to fixed wing is difficult as the rear motor just shuts off, shooting the aircraft straight up. Can someone help with me with the motor mix so the rear motor gradually shuts off in the final transition stage?