vibration reducing motor mount

Here it is. My homemade motor mount. It's easy to build, it's cheap and it has a good result on reducing motor vibrations. The only disatvantage is that motor temperature is a bit higher. If you mount the motors directly on to the aly frame the heat will flow in to the frame causing the motor to be cooler. In this case the motor mount blocks this temperature flow so to motors run warmer.

1) Take some material that you think will be strong enough to hold your motors and make some little plates (in pair). Size: a bit larger then your motor :)

2) 1 one plate you drill the holes you need to mount the motor and rubbers. On the other plate you drill the holes you need to mount this plate to you quadcopter frame and rubbers. In my case I use 6 rubber to hold 1 motor.

3) When pushing the rubbers in to the holes and attach the 2 plates. You will see that there will be no contact from motor to frame. It's that simple. If you have a smaller multicopter with less thrust you can use 4 rubbers. If you have a lager multicopter with more thrust just add some rubbers.



The rubbers I used for this motor mount are in fact computer case fan mounting rubbers. They are really cheap as you can see -> Case Fan Rubbers
I noticed that there exist professionel RC motor mount rubbers. But these are more expensive and hard to get. Maybe they give an even result. But as I said, my setup is really easy to build and it's very cheap.

Vibration troubles

Indeed, the Razor 9DOF imu is really sensitive to vibrations. Motor vibrations cause that much noise on the sensors that this board really can't be used in a multicopter. But you can fix this with some tips & tricks.

I really have tested everything to reduce vibrations. Nylon spacers/srews, foam, rubbers, rubber band,... just everything you can imagine. The only thing that really helps to reduce vibration noise is to make a motor mount that is completely saperated from the frame by some rubbers. I will give more details on this in my next blog.

With homemade motormount I was able to
- reduce GYRO noise to 1%
- reduce ACC noise with 90%

I noticed that the MAG on this IMU board is sensitive to EMF caused by motors and/or current. When motors spin up the data on the MAG shifts up or down. I'll investigate this later and try to find a fix for this problem. So Currently I can't use the DCM algoritme. But using GYRO and ACC raw data should be enough to get my quadcopter stable.

I also noticed that increasing the ACC update rate increases the noise on the raw data. I currently update my ACC at 12hz to get a good result.
But by using the GYRO (100hz) data and ACC (12hz) data in one formula I still have an output rate at 100hz!