Al's Cyclogyro The 'Baco-Liner' Mk.II *2nd Video Up* - Page 3

rotorheid · Oct 21, 2009, 10:36 AM

Hi Guys,

I managed to get her completed and test flown, needs a bit of fettling now, adjust the C/G and try again, after my holiday. My taxy leaves for the Airport in 2 hours, then, I'll be offski! real world here I come WooHoo!
Todays happy snaps and a video of the fun and games, I have to put back on the 12x6, pants! The rotor spar cracked in the middle, so now I can make a fitting to hold the two halves together. Cheers and out.

regards to all, Al

http://www.vimeo.com/7182817

gustavochacha · Oct 21, 2009, 10:48 AM

Congratulation Al!! and also congratulations to my compatriot Baco!!! we are colleagues in foro-aeromodelismo.com in Argentina.
Internationals greetings!!
Gustavo Caminos (CHACHA)

rotorheid · Oct 21, 2009, 10:59 AM

Hola! Gustavo

Good to hear from you, thank you, I tried to email Baco to let him know I was undertaking this project, please say Hi and thank him, from me, cheers!

regards Al

JochenK · Oct 21, 2009, 11:27 AM

Al,

she's flying, which is more than I ever thought she'd do. Congatulations!

Jochen

alfoot · Oct 21, 2009, 12:04 PM

Al,

That was great - it reminded me of a kite version I had when I was much younger

Look forward to the next development phase, like Jochen I am astounded that it flew so well.

This has got to be an Inter-Ex 2010 entrant Al.

The other Al

arrow5 · Oct 21, 2009, 01:27 PM

Interex definite Al. Plan your next years leave now !

Norfolk Flyer · Oct 21, 2009, 01:38 PM

Well done Al. Once you have sorted that CG issue this model will be a show stopper!
It was definitely nose high but really trying to fly despite it.

Good luck and best wishes,

John

jodini · Oct 21, 2009, 03:54 PM

That was awesome! Try, try again Al! Yes, hopefully a little lead in the front will get it to cut thru the air. It looked great...spun up good!

Boneswamped · Oct 21, 2009, 05:46 PM

Hello Al,
Great job with the build. When you work out the final kinks, I simply must have plans for that thing! I knew you could do it all along my friend.
Regards,
-Mike

P.S after watching the video several times; I think a bit of Dihedral between the rotors would help Roll stability. Same concept a trainer fixed wing with rudder and elevator only uses.

MarioIArguello · Oct 21, 2009, 06:53 PM

Al,

Just saw the video, have not had time to go over the whole thread and photo build...

Your rotor head is rigid (I think) and roll will take the rotor with the frame in a turn or wind gust, just like on your first test video. If you float the head or make the Center of the rotor head connection to the support semirigid or slightly flexible so that the spinning rotors stabilize themeselves, you will resolve the problem of the aircraft tipping over and taking the rotor along with it. This too could be fixed with lighweight stabilizer and rudder with suffiicient area to compensate for more control pitch and roll, with a rigid rotor mount.

You could mount the center main ball bearing in a rubber inner ring to allow for some dampening. Or float it completely in a gimbal and use two guy wire style springs to center the rotor bar and hold in place.

The durometer of the rubber or spring tension will determine the amount of flex or dampening, you will need to experiment a bit to find that magic point!. Not too tight , not too lose.

Also consider rotor and thrust prop direction, either supporting or counteracting torques involved.

Interesting build, seen photos of similar models in RC magazines but never saw one flying.

Boneswamped · Oct 21, 2009, 07:15 PM

I don't agree with Mario at all. Helicopter aerodynamics have nothing to do with this design. I'm suggesting dihedral between the two rotors in exactly the same fashion as a rudder/elevator only fixed wing. A flexible mount as Mario is suggesting would result in the rotor flapping up to the max allowable flex angle and staying there as long as lift is being produced by the rotor. Generally speaking, the rotors you made produce nearly the same lift vector as a fixed wing of the same size. There is no flapping, no lead/lag, and no dysymetry of lift(with the exception of a small amount from yaw differential) with this type of design. Enough of my rambling, I'm saying that a few degrees of positive dyhedral between the rotors should make the model much more stable.

-Mike

dgoslee · Oct 21, 2009, 07:30 PM

Quote:

Originally Posted by Boneswamped

Hello Al,
Great job with the build. When you work out the final kinks, I simply must have plans for that thing! I knew you could do it all along my friend.
Regards,
-Mike

P.S after watching the video several times; I think a bit of Dihedral between the rotors would help Roll stability. Same concept a trainer fixed wing with rudder and elevator only uses.

I doubt if dihedral would have any affect. Since the rotors have no inherant angle of attack, a yaw or side slip just wouldn't cause a lift differential.

Dan

Boneswamped · Oct 21, 2009, 07:38 PM

You're right there is no set angle of attack, however, the lift is perpendicular to the rotor. Yaw differential would be minimal do to yaw, but it is in fact mathematically there. So that being said, if there were dihedral between the two there would be Positive static stability built in. Seems like an easy thing to test in any event. One of the cylindrical lifting concepts NASA tested had built in dihedral(what do they know

).
Regards,
-Mike

imsofaman · Oct 21, 2009, 07:41 PM

I think dihedral will be what you are looking for Al. Your lift is being produced by each rolling wing. Just because it is a rolling wing.....does not mean all rules of aerodynamics are just thrown out the window.

You cant fly a flat wing with rudder and no ailerons. You need dihedral.....not much, maybe 3 or 4 degrees each side.

1. Add dihedral
2, you are tail heavy.....either add nose weight or move the mast back some.

Just my $.02 cents..............

Dave

imsofaman · Oct 21, 2009, 07:44 PM

Also....you may benefit with your tail feather ABOVE the turbulence of the rolling wing. Like a Mud Duck tail. Otherwise.....you may not have much control..........

Oct 21, 2009, 05:46 PM	#39
Boneswamped Registered User Join Date: Nov 2008 Location: DeRidder LA. Posts: 874	Hello Al, Great job with the build. When you work out the final kinks, I simply must have plans for that thing! I knew you could do it all along my friend. Regards, -Mike P.S after watching the video several times; I think a bit of Dihedral between the rotors would help Roll stability. Same concept a trainer fixed wing with rudder and elevator only uses. Last edited by Boneswamped; Oct 21, 2009 at 05:56 PM.

Oct 21, 2009, 06:53 PM	#40
MarioIArguello Registered User Join Date: Jun 2006 Posts: 1,310	Make the Rotor head Semirigid or Flex and you got it! Al, Just saw the video, have not had time to go over the whole thread and photo build... Your rotor head is rigid (I think) and roll will take the rotor with the frame in a turn or wind gust, just like on your first test video. If you float the head or make the Center of the rotor head connection to the support semirigid or slightly flexible so that the spinning rotors stabilize themeselves, you will resolve the problem of the aircraft tipping over and taking the rotor along with it. This too could be fixed with lighweight stabilizer and rudder with suffiicient area to compensate for more control pitch and roll, with a rigid rotor mount. You could mount the center main ball bearing in a rubber inner ring to allow for some dampening. Or float it completely in a gimbal and use two guy wire style springs to center the rotor bar and hold in place. The durometer of the rubber or spring tension will determine the amount of flex or dampening, you will need to experiment a bit to find that magic point!. Not too tight , not too lose. Also consider rotor and thrust prop direction, either supporting or counteracting torques involved. Interesting build, seen photos of similar models in RC magazines but never saw one flying. Last edited by MarioIArguello; Oct 21, 2009 at 07:10 PM.

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Oct 21, 2009, 10:48 AM	#32
gustavochacha Gustavo Caminos Join Date: Oct 2009 Location: Buenos Aires Posts: 68	Congratulation Al!! and also congratulations to my compatriot Baco!!! we are colleagues in foro-aeromodelismo.com in Argentina. Internationals greetings!! Gustavo Caminos (CHACHA)

Oct 21, 2009, 10:59 AM	#33
rotorheid This is my other autogyro! Join Date: May 2006 Location: Live in Inverness, Scotland, work away. Posts: 1,784	Hola! Gustavo Good to hear from you, thank you, I tried to email Baco to let him know I was undertaking this project, please say Hi and thank him, from me, cheers! regards Al

Oct 21, 2009, 11:27 AM	#34
JochenK Registered User Join Date: Jan 2005 Posts: 1,040	Al, she's flying, which is more than I ever thought she'd do. Congatulations! Jochen

Oct 21, 2009, 12:04 PM	#35
alfoot Keep it simple Join Date: Jan 2005 Location: Salisbury,England Posts: 624	Al, That was great - it reminded me of a kite version I had when I was much younger Look forward to the next development phase, like Jochen I am astounded that it flew so well. This has got to be an Inter-Ex 2010 entrant Al. The other Al

Oct 21, 2009, 01:27 PM	#36
arrow5 can you land on that ? Join Date: Jan 2005 Location: Scottish Highlands Posts: 1,870	Interex definite Al. Plan your next years leave now !

Oct 21, 2009, 01:38 PM	#37
Norfolk Flyer Suck it and see Join Date: Aug 2008 Location: Cromer, North Norfolk Coast, UK Posts: 378	Well done Al. Once you have sorted that CG issue this model will be a show stopper! It was definitely nose high but really trying to fly despite it. Good luck and best wishes, John

Oct 21, 2009, 03:54 PM	#38
jodini Registered User Join Date: Sep 2004 Location: Omaha Millard, Nebraska, United States Posts: 1,393	That was awesome! Try, try again Al! Yes, hopefully a little lead in the front will get it to cut thru the air. It looked great...spun up good!

Oct 21, 2009, 07:15 PM	#41
Boneswamped Registered User Join Date: Nov 2008 Location: DeRidder LA. Posts: 874	I don't agree with Mario at all. Helicopter aerodynamics have nothing to do with this design. I'm suggesting dihedral between the two rotors in exactly the same fashion as a rudder/elevator only fixed wing. A flexible mount as Mario is suggesting would result in the rotor flapping up to the max allowable flex angle and staying there as long as lift is being produced by the rotor. Generally speaking, the rotors you made produce nearly the same lift vector as a fixed wing of the same size. There is no flapping, no lead/lag, and no dysymetry of lift(with the exception of a small amount from yaw differential) with this type of design. Enough of my rambling, I'm saying that a few degrees of positive dyhedral between the rotors should make the model much more stable. -Mike

Oct 21, 2009, 07:38 PM	#43
Boneswamped Registered User Join Date: Nov 2008 Location: DeRidder LA. Posts: 874	You're right there is no set angle of attack, however, the lift is perpendicular to the rotor. Yaw differential would be minimal do to yaw, but it is in fact mathematically there. So that being said, if there were dihedral between the two there would be Positive static stability built in. Seems like an easy thing to test in any event. One of the cylindrical lifting concepts NASA tested had built in dihedral(what do they know ). Regards, -Mike

Oct 21, 2009, 07:41 PM	#44
imsofaman Viva Juan De La Cierva Join Date: Aug 2003 Location: NJ Posts: 4,805	I think dihedral will be what you are looking for Al. Your lift is being produced by each rolling wing. Just because it is a rolling wing.....does not mean all rules of aerodynamics are just thrown out the window. You cant fly a flat wing with rudder and no ailerons. You need dihedral.....not much, maybe 3 or 4 degrees each side. 1. Add dihedral 2, you are tail heavy.....either add nose weight or move the mast back some. Just my $.02 cents.............. Dave

Oct 21, 2009, 07:44 PM	#45
imsofaman Viva Juan De La Cierva Join Date: Aug 2003 Location: NJ Posts: 4,805	Also....you may benefit with your tail feather ABOVE the turbulence of the rolling wing. Like a Mud Duck tail. Otherwise.....you may not have much control..........