Morphing airframes and Human interface rotor disc control

[davh12]

I was wondering what all of you might think of this concept. I've caused a little discussion already, but some assumed that my design is fixed pitch, but it still has collective pitch. :usa:I've got a patent in the works and it left the classification contractor. I presented this concept to DARPA. They said the work in my outline had merit, but felt the pay was not high enough for DOD to "Advance the state of the art" as they called it. It surprised me a little because DARPA had just closed a BAA proposal for a Mission Adaptive Rotor system (MAR).
http://www.darpa.mil/tto/programs/mar/index.html
http://www.theregister.co.uk/2009/02/darpa_morph_copter
But according to some, the "industry" usually pays no attention to the private sector and "small entities" such as myself. I did get a call from Bell Helicopters and they were up front with me. They would've considered looking at my design, but the guy that I spoke with in the XworkX department told me that Bell's legal department told him "hands off" because I'm still active duty army. I'm not in the army aviation. I've always been Infantry, but I have a cognitive interset in rotorcraft and someone once told me that I could not do this, so I had to prove them wrong and do it anyway. I'm working on a small scale proof of concept prototype. www.envisionhelicopters.com is my newly created site, but it's still not finished and it may not pop on google because it's too new. You can leave comments at my site around 1 July when I upgrade.
What leads me to believe that my design will work is that there are already two types of helicopters that have "mast tilting" that are flying now in kit form. One uses a gimbal joint like mine, the GEN H4( http://www.gen-corp.jp/)but it's coaxile and fixed pitch....no human interface & no morphing airframe and most importantly no auto-rotation. The other is the airscooter ( http://www.airscooter.com/) which uses a CV joint and tilts a coaxile rotor system, but it also is fixed pitch and cannot auto. The gimbaled airframe came about in my efforts to design a tilt-mast helicopter that was not fixed pitch. The human interface control came about in my efforts to provide better control and stability when stick input is applied to control the airframe & rotor disc in a tilt mast design, but not just a "T" handle control stick to manipulate the tilting as seen in the GEN H4.
Charles Seibel, also made a prototype helicopter that the cockpit would slide forward, aft and in lateral fashion thereby changing the CG and causing the helicopter to fly in that direction ( www.aviastar.org/helicopters_eng/seibel_s-4.php). Any of you rotor heads got any suggestions about anything I've mentioned? Thanks.:usa:

David

[joe nelson]

Dave,

Welcome to the forum. I am glad to see another experimenter on the forum which adds to gyro community.

Fort Benning is a great place to which I've spent many uncomfortable months there! LOL.

[BEN S]

I was interested in your website, I have often envisioned a helicopter that has a central pivot point halfway up the mast and a slightly curved track at the bottom which could transition from tilted forward mast for vertical takeoff and landing to folded back to be a gyroplane. I just couldn't come up with a reason to transition to gyroplane if you were already carrying the weight of the intricate parts for making a helicopter.
I spent a LOT of time in T&E for the U.S. Gov't and one thing I learned early on, it's not making the better mousetrap that most of the contractors are interested in, but rather making it to the next level of funding! Sometimes in spite of the system really great products are born!
Good luck with your endevors, but be aware if you are in ANY way still conected with the U.S.Gov't and actually do come up with a great idea, they will be the ones to hold the intellectual rights, weather you are a cook or an engineer. I saw it happen on a weekly basis, hell I once invented a simple fuze that smoked the one being tested would work all the time and was CHEAPER! They thanked me for my participation and reminded me quickly that I and my ideas BELONGED to them! (then shelved the idea)
If you truly have the next great idea, maybe you should move to the private sector before mentioning it.
Anyway, good luck and keep working.
Ben S

[davh12]

Yeah, but I did try and present it to Bell helicopters and they wanted to be hands off because of the army. I told them that I have 5 to 7 more rotor systems, each different from the other and that if I had to I would sit on those ideas until I retire. An "associate inventor" and friend had a rotor system that he presented to , MDHS (Boeing) and GA Tech. He was a civilian and he got the "dirty end of the stick". I just posted a brief description on his split axial tilt mast. NASA Ames did a "piece" on this rotor system a few years after he got cheated..... go figure. His idea was patented too. I have a few more of his sketchs to post as well...with his permission of course. So, that's why I figured that I would risk it anyway. I already changed the rotor controls and some portions of the airframe on my design. The one that you see now will work, I believe, but the next changes are "patentable" diffferences and will be " Method of Morphing Airframe Rotor Control". That one is going to wait until I'm retired from the Army in a few years and it's not part of the other 6 or so rotor systems. I spent years thinking about rotor systems. Some call me a nerd, but that's ok. I'm Infantry and tired of people thinking that we're dumb grunts. I work on cars and other mechanical stuff. I love to figure out complicated mechanical gadgets. It's almost like OCD, but in a good way.

Dave

[davh12]

Joe,

Yep...still many misarable months...nothing has changed for grunts. After my second deployment to Iraq they sent me here to be an instructor at IBLOC (Infantry Basic Officer Leadership Course). It's differnt than being in line infantry. The original intent for my design was for mast tilting to vector the thrust better, but after looking at it fo a bit, I noticed that the tilt reward should facilitate auto-rotation with regard to the relative wing passing up through the blades like a gyro. We'll see in time.

Regards,

David

[davh12]

Ben,,
I see your point about the weight. I've been cutting and trimming the small scale flying prototype to cut weight any where I can. The electric motor is too weak and the blades are not symmetrical or asymmetrical airfoils...just fixed pitch hobby copter fan blades. I have some adjustments to make , including tweaking and changing some parts.

Regards,

Dave

[joe nelson]

this should bring back you threat!

[davh12]

Wow...lost all my stuff. Quess the glich hit it.
TR motor went out on the single mast boom and pod. Last week-end I started a coaxial version of my patent while I wait on parts, still morphing airframes. Got most of it done. Concerned about the teetering point between the two airframes and adjusting it would add additional weight.

Finished the battery carriage last night and positioning of the forward/aft pitch horn ball link. Pics/vid clip this week-end.

Dave

Hub-lock-1 (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=rMbSqAl8v_k)

Hub-lock2 (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=y01LScw4KUQ&feature=related)

[davh12]

Coaxial platform is almost done. Glue needs to dry over night. This platform is still a mechanial morphing airframe for rotor disc control. The yaw control surface uses one bearing and is hinged to allow the assembly to tilt with the upper airframe. Battery carriage is attached to the lowest portion of the upper airframe that runs down through the lower airframe and hinged. The upper portion is attached to the lower airframe forward to distribute weight between the two airframes. I'm still tweaking the single mast boom and pod. Vid clip posted shortly. Pics are the before and after. I had to cut away the swash plate because the helo was so small. I could not disassemble it easily. Test flight tomorrow.

Dave




coaxial-1 (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=sDCCuABtHIc)

[davh12]

Last night did a quick short hop. Smooth hover, but not sufficient control. Much like the indoor IR control helos. The yaw control surface was not large enough. I was worried about adding weight, so made a CF frame and filled the surface area in with a strip of scotch tape. Glue is drying. Next flight tomorrow morning.

Dave

Coaxial 2 (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=xhbi-RGkydg)

[davh12]

Crashed the coaxial platform into the dining room light and broke the fly bar. Repairs made and working through weight distribution: too much weight forward. I'll spin the upper airframe around, cut, extend and re-solder the motor wires. Yaw surface still needs to be longer.

Dave
Coaxial-3 (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=pNOmRpSrCE4)

[joe nelson]

Dave,

You are further along than me! At least, you're flying. :)

[davh12]

I did not notice it in this vid clip, but the wall smack earlier bent the inner mast, caused clockwise downward descent. Replacing mast tommorrow.
I had been rethinking centrifugal force, as it applies to this particular "morphing airframe" More to follow, but I think I get this one figured out.
Dave
Bent mast.mov - YouTube (http://www.youtube.com/watch?v=6OOSpu_R4k4)

[davh12]

Pitch and yaw control surface are both good. Added a 2nd weighted fly bar. With the masts tilted forward, the top hub fly bar stays in it's plane of rotation due to centrifugal force. With mast tilt, the blade over the forward airframe increases in pitch parallel with the span of the blades, causing the blade aft to decrease in pitch and lift. Adding the 2nd fly bar to the lower hub allows equal lift aft in this coaxial system. I'm just speculating, but this should keep the lift equal between the 2 rotor discs...."knock on wood".

Completed coaxial system with two separate airframe joined; forward and aft tilt and yaw control. It's not like the Airscooter or GEN H4 with an airframe suspended below a power plant and rotor assembly. Tilt in the masts on the upper airframe causes change at equal moments in the lower airframe, weight distributed between the two airframe to prevent a "pendulum effect". Flying it tomorrow.

Dave

Pitch-Yaw (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=3L4fHfur61c)

Complete (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=70lGQ-Q1Rw4)

[davh12]

Foolish am I. I did not pay attention to the lower hub. Top hub fly bar is leading edge to leading edge. The lower fly bar should have been trailing edge to trailing edge to increase pitch/lift on opposite sides of the airframe forward/aft between the 2 rotor discs. I had both leading edge mounted. It fly perfectly in reverse/aft. Corrections made tonight, vids posted tomorrow. I had to trim some weight off of the airframe as well.

[davh12]

The coaxial system w/ 2 fly bars works ok, but both fly bars need to
be leading edge to leading edge. Trailing edge to trailing edge causes
failure in the system.

When fly bars oriented leading edge to leading edge on both hubs are
integrated into my airframe the lift across the rotor discs is
reversed, so when the masts are tilted forward, the fly bars generate
more lift over the forward portion of the rotor discs and thrust
vectoring is negated a great deal causing it to fly aft. The small
scale that I've chosen does not have sufficient servo span of motion
to affect flight direction. Larger scale needed. Going back to the
single mast for now, but I'm not giving up. I've learned quite a bit
about this mechanical morphing airframe. So, with regard to the
coaxial, in theory if a have servos with more range of motion,
tilting the masts forward will cause aft flight and aft mast tilt,
forward flight, but it' s 180 degrees from my original intent which is
thrust vertoring and morphing airframe rotor disc control. I believe
that torsion bars for flapping, lead/lag would be better. I'm going to
keep tweeking both rotor system set ups
Servo-span (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=Gxqz3bk7EaY)

Reverse (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=0bF45CimjRQ)

[davh12]

In this clip the upper hub fly bar is leading edge oriented and the
lower hub trailing edge to trailing edge. It failed. For this set up
with my airframe, leading edge to leading edge is needed on both hubs.
I still need to experiment with trying a larger coaxial with better
servos because I'm curious now if more manipulation imparts better
control as well the "reversed lift versus mast orientation" with
regard to mechanical morphing. If they does not work, I want to try a
torsion bar set up for flapping "hinge" action.

Flybar-Nogo (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=LzAmsrfFdZ0)

[davh12]

4 bladed rotor hub is coming along. I still have some work to do on the airframe, CF motor mount, and minor soldering.
4 blade hub (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=3XX2gvFxQjA)

[davh12]

1st CG hang after boom extension.

CG-tail boom (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=xvMpU-WzcSc)

[davh12]

Forward landing strut extended; minor CG adjustments to follow; blades balance.....4 bladed are a pain. Shooting for weekend after next for flight/crash

Tailboom-2 (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=MuENCNJwtUc)

[davh12]

Murphy is kicking me while I'm down again, but I plan to get a reverse set of rotor blades today. The CF layered tail boom was too heavy for the airframe. Center of gravity is ok now, but I'll utilize an aluminum tail boom now. At least I have 1/2" to play with for CG adjustments. The 4 bladed hub was mostly balanced, but "mostly" does not cut it. I do not have a mill anymore, so I may need to just buy an aluminum hub. Changes are already in the process of being completed and should be posted tomorrow.
Reverse blade (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=v5KTgVCuM5Q)

[davh12]

Aluminum tube tailboom cut a good deal of the weight and cleaned up the wiring routed from the TR.

Alum-tail (Ipod Video).mov - YouTube (http://www.youtube.com/watch?v=Lnlo7VmDexo)