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Old Oct 19, 2008, 06:44 PM
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Bobnormal's Avatar
United States, CA, Ontario
Joined Mar 2006
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Yet another VTOL

Hello all,Since I began too suck lately with successful designs,I thought I'd try something different,and since I've always wanted a driveway toy I figured what the hey.After looking thru the VTOL forum I came up with a hybrid ducted/airfoil design of sorts.
Since the problem with all VTOL seems to be rotational torque(sic)I offset all for vane/wing /control surfaces 6 degrees,as if it flew horizontal,get it?
I built a 12"dia. by 12" tall duct that will eventually control the airflow over the positioning vanes and the control surfaces.but for now I'm leaving it off until I get my equipment positioned well,I Will Finish This,and I Will Shoot Video,next comes the electronics layout.
I know this should probably be in the VTOL forum,but it's a foamie,it's scratchbuilt,and you guys are my friends in the lonely world of scratchbuilding,
Any help would be appreciated,
Bob
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Old Oct 19, 2008, 07:32 PM
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United States, CA, Ontario
Joined Mar 2006
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I just threw some gear on it for a static test,no servos just motor,it seemed fine rotationally but rolled over just after liftoff,Broke prop...........'
Bob
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Old Oct 19, 2008, 07:39 PM
-+- PhlatBoyz -+-
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New Jersey
Joined Sep 2003
1,333 Posts
Looks cool,
One thing I would say is that and edf unit will be to weak to lift that in vertical takeoff.

I have built a few of these type of VTOL flyers and the best unit for hover seems to be a 12" prop.
Seems the larger the prop the better to keep it from wanting to tip over all the time.
Large bottom control fins (like you have) and keeping all the electronics weight to the top right under the motor helps to keep it balanced as well.

I have a few out there one called the NightOWl and the other is GoldenEYE
Do a search and you will find some info on them.
I am going to make a plan set to cut the NightOWL out on the Phlatprinter soon.
Mark
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Old Oct 19, 2008, 07:58 PM
Winging it >
leadfeather's Avatar
Joined May 2006
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Bob, looks interesting , good luck!

Kram, I'll be looking up your VTOl's.
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Old Oct 19, 2008, 08:44 PM
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United States, CA, Ontario
Joined Mar 2006
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Kram thanks Leadfeather as well,Kram I'm just using the EDF housing to mount a motor,at least 12" prop on a bp 2108 or 09(trying both). This is a fun experiment as for once I don't have clue.Actually yes I do. thrust is a very predictable thing,I predict you will be affected by it.Now I cut the duct at a 3degree up to match the the vanes,I'm not going permanent with the duct just yet,until I get the servos squared away,
Bob
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Old Oct 19, 2008, 08:47 PM
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United States, CA, Ontario
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Kram you would think to put the weight low, why does it seem to work opposite?
Bob
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Old Oct 19, 2008, 08:51 PM
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United States, CA, Ontario
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As far as Electronics goes it's something like this...
Power is not an issue,as I have multiple powerplants and props to experiment with....
I plan on startng with an Elevon setup for 2 surfaces and thinking about setting up rudder on the other 2 using a simple aileron splitter to create a type of Rudderon as it were,Ideas?
Bob
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Old Oct 19, 2008, 09:38 PM
Winging it >
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Joined May 2006
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This full size VTOL was done back in the 50's. Cg was actually well above the props and yet it was inherently stable...not intuitive at all.

http://www.youtube.com/watch?v=dmSCyy0_OX4
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Old Oct 19, 2008, 09:54 PM
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United States, CA, Ontario
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Amazing and something to be explored.CG above the prop?I'm not the human on top so it's hard to say how I could control that,I've read some crazy things,battery on top of the prop on a swashplate etc, but there has to be a better way,
Bob
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Old Oct 20, 2008, 12:28 AM
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Joined Aug 2004
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How about gyros to help contol your elevons and hold it in the vertical position until you push over into level flight????
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Old Oct 21, 2008, 02:33 PM
Winging it >
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Joined May 2006
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Another high cg craft

Check this out, talk about high cg

Inverted Heli-Max AXE-EZ Coaxial R/C Helicopter (1 min 55 sec)
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Old Oct 21, 2008, 04:11 PM
My plans are in my blog
Rusty-Gunn's Avatar
Kotzebue, Alaska
Joined May 2006
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Concerning the heli, I tend to think the blades (varible pitch) force it to remain steady, the pilot merely adjusting the blade pitch to maintain upside down orientation. The heli's natural tendency is to flip rightside up though.
You guys are doing cool research with your various designs, and making the VTOL planes very interesting of late. Keep up the good work.
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Old Oct 21, 2008, 06:02 PM
Sopwith Camel's Cousin
Between my tx and crashed aircraft
Joined Mar 2006
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Quote:
Originally Posted by Rusty-Gunn
Concerning the heli, I tend to think the blades (varible pitch) force it to remain steady, the pilot merely adjusting the blade pitch to maintain upside down orientation. The heli's natural tendency is to flip rightside up though.
...
Having flown some beginner's helicopters (fixed pitch), I can tell you that the words "steady" and "helicopter" do not go together all that well.
Even right side-up (and as normal, with a gyro controlling the rudder), helicopters have a tendency (at least for beginners) to tilt and move all over the place when one is trying to hover them
(the phrase 'swinging pendulum of death' comes to mind).
An exception are the co-axial helicopters.

Some VTOL threads (all within RC Groups):
sloper steve has a "hoverfoam" thread
VTO: http://www.rcgroups.com/forums/showthread.php?t=200470
Mini JAR: http://www.rcgroups.com/forums/showthread.php?t=459443
Sumo 3D: http://www.rcgroups.com/forums/showthread.php?t=710077

When comparing RC planes and helicopters:
1. with planes, I can flat turn (well left turns, anyways), split-S, loop
2. with helicopters, I am still working on right-side up hovering,
and I started with helicopters
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Old Oct 22, 2008, 11:31 PM
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Bobnormal's Avatar
United States, CA, Ontario
Joined Mar 2006
898 Posts
Shameless bump

Update,Work and lot's of(economy anyone?)it.Ready for servos. I still don't buy the High CG thing but am making provisions for it,to be sure.
The duct is currently removable,as it should be for access to the gear,but I will find a way to attach it like we do with wings,Black and White anyone?
Bob
P.S. Firefox does not handle text below your pix,tends to crash,,,beware,
Bob
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Old Oct 22, 2008, 11:34 PM
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United States, CA, Ontario
Joined Mar 2006
898 Posts
Just looking at that hacked round shape,remember we use wirenuts! for ESC to everthing,HAHAHAHAA!,
Bob
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