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HomeAircraftHelicopterAerial Photography and Video › Multi-copter progress
01-13-2009 01:40 AM  9 years agoPost 21
eyeinsky

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Fall River, Nova Scotia, Canada

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John

Awesome looking heli

I haven't started yet but I have design that I was hoping to get in to small scale proto type this year. I have also thought of using the 3 rotor system like you. Two collective counter rotating rotors that will produce the main lift, powered by one motor belt driven. Then use the third smaller rotor as a tail rotor similar to what you have done but instead of cyclic control, use rotor tilt for torque input for turning and collective inputs to tail rotor for fwd and aft flight. This system only requires 4 servos one for each collective and one for the rotor tilt. It still would require possibly 3 gyro stab system one for each main lift rotor to stabilize roll and one on tail rotor tilt for rudder. Possibly could incorporate a forth gyro on tail rotor collective to stabilize pitch

“In a nut shell” I would be like controlling 3 tail rotors with one tilt input for rudder or torque component control.

Look fwd to seeing some video.

Cheers Jerry

Hard job competing with gravity.

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01-13-2009 03:07 PM  9 years agoPost 22
aambrose

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Pana, IL

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Yeah the cold temps and high winds stink around here. I'm ready for spring!

Regardless of what kind of video or stills that thing can produce, it just looks like it would be a blast to fly! Reminds me of a scorpion. Imagine one using 3 sets of 800mm blades! grunt grunt grunt!


Tony

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01-15-2009 08:50 AM  9 years agoPost 23
wxyz

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calif*, U know where

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The problem with tri rotors is coupling of roll & yaw. You always get a yaw from a roll & need to waste power to compensate for it. When the Draganfly X6 rolls, it rolls its aft rotor & probably burns battery power to counter it. Mind you, this is only what the test stand is showing. Flight may be different. Here's 3 boom yaw coupling on Goo Tube.

Watch at YouTube

It's real hard to improve on the basic fixed pitch quad rotor. The quad rotor is like a table in the sky. It doesn't care where the wind is coming from or how it's tilted, but it's very sensitive to center of gravity.

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01-15-2009 01:07 PM  9 years agoPost 24
Djago

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Nederland

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I see some issues with your setup.
You are using 5 engines instead of 6 (to mimic the Draganflyer).
If want to mimic the draganflyer use this algorithm:
FYI Draganflyer X6 doesn't roll one its motors (like traditional tricopters)

MR=Motor Rear
MFL=Motor Front Left
MFR=Motor Front Right

1= Top
2= Bottom

T=Thrust (collective)
N=Nick (Pitch)
R=Roll
Y=Yaw

MR1=T+N+Y
MFL1=T+R-0.5*N+Y
MFR1=T-R-0.5*N+Y
MR2=T+N-Y
MFL2=T+R-0.5*N-Y
MFR2=T-R-0.5*N-Y

Also if you are using a "T" frame instead of a "Y" frame make sure the CG is roughly the same as the Y.
From the vid is looks like the CG is too far forward.

with the above info redo the test....
You will see that this there will be hardly no cross coupling then.
And have the same symmetry of lift as a quad.

Peter

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01-15-2009 01:43 PM  9 years agoPost 25
papatango

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Toronto, Ontario, Canada

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^^^^^^^^.... One image came to mind;

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01-15-2009 02:04 PM  9 years agoPost 26
nooobs

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web

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...

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01-15-2009 02:31 PM  9 years agoPost 27
papatango

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Toronto, Ontario, Canada

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LMAO!!!

I want that on a T-shirt.

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01-15-2009 06:24 PM  9 years agoPost 28
wxyz

rrApprentice

calif*, U know where

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Typical business in any Asian city.

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