Multirotor Advice

[Micah Carr]

Hi all: Im looking for advice on a octocoptor build I plan on making.
I am currently a college student enrolled for electrical engineering technology and computer science. I have never before built or flown a multirotor but I have done quite a lot of research on them and I have a good understanding of how they work.
Normally I don't need to resort to posting threads in forums but the build I plan on making is extremely unique and the complete opposite of what most people look for in a multirotor.

What I'm trying to achieve in this build is an octocopter which is extremely stable but has no need to carry a whole lot of weight, nor do I need it to be very agile or fast or high flying. Actually it will be flying at very low altitudes. probably lower than 4 feet

So what I'm looking for here is advice on prop and motor recommendations for an extremely stable system that can make minute adjustments to keep it level with minimum vibrations.

I was thinking that a lower pitch prop with a high speed motor can make smaller adjustments to keep it more stable with less potential vibrations.

Any feedback and advice will be greatly appreciated!


Some more info about the design:

• The plan is for the octocopter to stay as level as possible at all times.
• So how does it move? Each arm will be able to rotate slightly to drive it in whichever direction it needs to go and rotate.
• This should allow it to stay level and keep a stable altitude while moving and rotating
• The octocopter will be using motors in pairs (1 CW and 1 CCW) to stay level similar to a quadcopter so I dont need to worry about the torque from staying level effecting the rotation of the machine.

• I will be building the frame out of carbon fiber which I will mold myself.
• I will also be programming my own control board to drive this system.
• I have not built the frame yet. nor do I have dimensions or estimate weight set as of now.

 

[Motopreserve]

Wow! Very interesting. I'm curious to follow along and see what you come up with. Definitely sounds like you're thinking outside the box with each arm being able to articulate.

Are you planning on using servos to drive the arms? Will the arms work in conjunction with the speed of the motor/props to produce directional movement?

You might look into the technique DJI is using on the Inspire to handle readings of the ground for the low flying. I believe 3DR may also use sonar???

Good luck and fly safe!

 

[Micah Carr]

Thank you for your input!

Are you planning on using servos to drive the arms? Will the arms work in conjunction with the speed of the motor/props to produce directional movement?

Yes, this is what I plan on doing.


I am considering using a laser distance sensor rather than ultrasonic for more precise altitude readings.

 

[Motopreserve]

That's awesome. After replying before, I saw that a few guys were hard at work on a smaller 350 size quad with articulating arms. The thread is here on MRF if you haven't seen it. Exciting times!

I don't care what magic you use to achieve it, but if you can get precise altitude readings without me having to use some open cell foam over a barometer - I'm in!!!