Angled Motor Mounts - How different motor angles effect flight characteristics

[Dragon]

Getting into FPV with a quadcopter etc it soon becomes apparent that with a standard set up (horizontal camera and motor mounts) you spend a lot of time looking at the ground which is not great, especially at low level.

One option to remedy for this is to install angled motor mounts.

I have done this with 10 degree forwards mounts made for a QAV250 on a diatone silver blade.
The fist problem is my DYS 1806 motors, due to two of the bolt holes being closer together they can only be mounted in certain positions on the frame arms.

The result is the front two motors are angled forward 10deg and slightly outwards, and the rear two 10deg forwards and slightly inwards.

It seems to fly ok, but I have not had chance to test it fully.

Can anyone explain how this configuration will in theory effect flight characteristics, such as stability, hover, barrel rolls, flips, cornering etc.

See link (my flickr account) to diagram below for more details.
https://flic.kr/p/v9NN4b

Thanks in advance

 

[SleepyC]

Have you considered a 1 axis gimbal that rolls the camera slightly as you pitch forward? That way your flight characteristics remain constant. I have seen several guys do this with much success.

 

[Dragon]

Well I have done multiple test flights and here are my conclusions

• Flys very fast forward more so or so it feels than flat mounts

• sluggish in the turns, barrel rolls not as quick and seem to end it side ways drift

• tried turning front ones inwards too and it flys vey well, fast stable barrell rolls but seems very twitchy

• tried leaving rear ones 10 deg forwards and slightly turned in but changing front ones back to standard flat mounts, dosn't seem to go forwards as quick, barrell rolls good but pitch and roll still a little twitchy
  
  
  My conclusion so far is tilted 10 deg forward mounts are great for fpv racing but all motors need to be facing forward and not turned in or out, or pitch and roll will be affected, either unbalanced beteen front and rear and perhaps the quad itself, and will result in over or understeer depending on the set up.
  
  Potentially forward mounting rear and flat front could work well, but based on my testing I believe all tilted forward and facing straight is the best set up.
  
  However to take it a step further, perhaps tilted forward (z axis), facing straight (x axis), but tilted in (y axis) may be an interesting set up, but I am not optimistic, and it may just result in similar issues.

 

[matwelli]

angled forward tends to reduce yaw response, angling out will increase yaw response (on a normal rotoation quad) we aheva very sucessfull one over here with 25 deg forward tilt and 10 deg angled in (all 4 motors have been reveresd from normal)