This is my latest multirotor, it was made entirely on a Laser cutter every single part (but the electronics)
The camera Gimbel is also laser cut and the entire thing is my design.
Just thought i would like to get your guys thoughts on it.
~A few notes on the design
The arms are raised above the CG to give stability in stable hover and decent.
The motors have a 10% outwards tilt this gives a higher flight speed by allowing a larger tilt in flight, it also gives stability when descending or ascending as the motors give a minute amount of horizontal control.
the under mounting of the motors give a around a 9%efficiency increase as the air is not thrusted onto the arms.
the overall result is a inherently stable design, in one of my recorded flights the motors are completely cut for a few seconds and the copter glides down as the motors auto rotate, it didn't flip or roll or oscillate, it simple glided down.
here is move video footage
Comments
Hi,
Very nice looking build. Well done.
What prop size do you use and how did you fix them on those motors? Do you have a close up picture of your electronics placement?
that is correct Euan al but he condition, no matter the frame setup or type this would still apply.
the only axis that looses some control is yaw, but it is minute and not much flying is done using yaw.
Thanks for the detailed weight report!
cool, thanks!
So...to translate...I think you said (for forward flight):
- the motors on the bottom are actually pointing 10% more toward the ground (increasing lift)
- the motors on the top are 10% more horizontal (increasing forward thrust).
- the ones inbetween provide yaw stability
Is that about right? There would be a condition on this that the frame is an "X" format.
ok so i didnt do the calculations, they were done by some company which was looking into how to increase flight time and efficiency of multirotors, after their commission ran out, they just had this info laying around, i was talking to someone i met on DIY drones aan they told me all this info, i had a think about it and it was sound in my head.
The higher speed you get from the 10% angle is because when flying you cannot really go past 45% tilt as the aerodynamics of the frame and loss of down draft cause the copter to loose altitude.
But the higher the angle on the motors, the shallower angle you need for the same speed but the higher the angle you can go whilst still maintaining enough lift. as some of the motors will still point down when flying at an angle and some will point horizontal giving horizontal thrust.
I would be interested to hear how you calculated the 9% efficiency increase. I understand that the moving air above the prop is wider and moving slower and therefore an obstruction above the prop will result in less drag than the same obstruction below the prop.
I am also interested to hear how the 10% outward tilt increases the flight speed or allows a larger tilt.
Impressive construction!
Excellent design touches, ones I try to use myself.
I too have the outward tilt (only 7' though, using 2 x M3 washers on the 2 outside motor mount holes, bewtween the plate and clamp) on my camera rig, and purposely keep as much below the prop line as possible. One reason I hate compassmot; because - without spending money on an external compass - the best results need the APM lifted considerably above the noise - especially for us 6S/high amp users. And that means lifting it above the prop line. It's only a few grams admittedly, but it's the principle ;-)
oh yeah i was kinda crapping myself
yes indeed low pressure is created, but when air is being sucked through to the low pressure area, it doesn't effect the surrounding airflow to much but when air is blow onto the arm, it pushes out sideways and makes the down flow turbulent and the blades loose efficiency
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