"Thank you for your good advice,I had thought about this question,at last I use this design is for reducing the affect of concussion of pump to parts on center plate such as imu etc.
There will be a clear answer after test! "
This octocopter is designed and built by myself,for spraying pesticides. wheelbase140CM,Max payload 15kg.made of pure carbon fiber board by CNC,and foldable in order to easy to carry!