Angled Motor Mounts - How different motor angles effect flight characteristics

D

Dragon

New Member
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
 
Well I have now 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.
Any comments....can anyone explain how these changes may theoretically affect flight characteristics from physics perspective?
 
Sounds like some great experimentation. I have wondered this for a while.

Here is another idea, if you were to make it shaped where it would have like a wing that way when you go almost vertical there would be less drop; and therefore you could go faster. I might do it yet haha. I love to see these types of post.


After I finish with what iam doing I plan to give a more lengthy response.
 
Here's another way.----- http://www.hobbyking.com/hobbyking/...rglass_Pan_Tilt_Camera_Mount_L_Size_.html---- mount this upside down without the servos or linkage. Make sure it doesn't pivot. Mount your board camera. Make sure it moves freely. Add a small amount of modeling clay to the bottom of the camera. Cut 1" square of thin modeling foam board and tape it to the top of the camera board with about 1/2" sticking over the top. As you fly forward slowly the weight of the clay will keep the camera straight. When you throttle up and the quad tilts forward the wind will push on the foam board and level the camera. You will have to adjust the amount of clay and how much foam board protrudes to dial it in. It doesn't react instantly but it's reasonably quick. I was down to the final adjustment when I flew into the side of a shed in the middle of a field. Pitiful. The only thing out there and I hit it. I have ordered more stuff and will try again. Give it a shot. It sure is cheap and uncomplicated.
 
One more thing. Use a 10mm tall nylon standoff about 3/8" in front of the bottom of the camera board to keep it from over rotating. You can adjust it to suit later.
 
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