X8 Thrust Vectoring

[maxwelltub]

So I am building an X8 and I am trying to do some research on proper thrust vectoring. I know that some people have talked a bit about tilting their motors slightly to give better yaw authority. The new GD-X8 motor mounts allow for thrust vector adjustment. Any of the experts care to chime in on this.

 

[gtranquilla]

I am no expert but please permit me to share what I have found so far....
http://www.mikrokopter.de/ucwiki/en/AngleAdapter.
I have no idea if this is really necessary for an X8 though.
There is also a pdf available that seems to explain it all on the Freefly Forum about this entitled "Mathematical Dynamics of a Quadrocopter represented in the Special Eucledian Group SE3." but I am not sure how to upload it from my PC to MRF!

It seems that better yaw authority can also help to tighten up a set course bearing so that the MR does not randomly yaw cw or ccw.... it also helps to balance the current draw between the motors on a single plane.... in your case your lower motors will probably draw less current anyway.

So I am building an X8 and I am trying to do some research on proper thrust vectoring. I know that some people have talked a bit about tilting their motors slightly to give better yaw authority. The new GD-X8 motor mounts allow for thrust vector adjustment. Any of the experts care to chime in on this.

 

[FerdinandK]

The best you can do for good yaw reaction/stability is to level the motors (the error should be smaller than 0,5°). If you want to turn your motors a few degrees, that does not help in stability/reaction, it does help with "force", so if you have a big and heavy rig (with big and heavy payload) you get more turning speed on yaw, more force. But the reaction/stability is more controlled by the speed of your FC/ECS/Motor chain. The momentum on the motors does chance in the moment the ESCs raises power on the motor, the thrust of the motor comes along as the rpm changes which takes more time. So, from my point of view, take your time and level your motors on the X8, if you are not satisfied with the yaw behavior, level them better (and adjust the gains).

If you do "thrust-vectoring" on an X8 (coax setup), you have to take care, that if the top motor is turned in the one direction, the bottom motor has to be turned to the other, to support yaw.

best regards
Ferdinand