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Old Sep 10, 2011, 02:53 PM
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Spoiler flight dynamics:

Spoiler flight dynamics:

Here are four illustrations that I hope will clarify how the spoilers work.

Plate number 4, in this illustration the sphere is in a hover with the relative wind entering equally into the sides and the top of the propeller, please note that both spoilers are horizontal, or you could say both spoilers are in a neutral mode.

Plate number 5, this illustration shows the craft in a gentle roll to the left. The roll control vanes are deflected and now the craft is starting to transverse to the left. Please note the relative wind on the left-hand side of the craft is directed horizontally across the left hand spoiler (in a neutral position) but on the right hand side of the craft the relative wind is coming at a angle that the deflects the spoiler downward. This deflected downward spoiler creates drag and a rotational force that opposes the force of the control vane, thus the spoiler has a tendency to dampen the roll rate to the left.

Plate number 6, this illustrates a roll to the right.

Plate number 7, this illustration shows the craft in a high speed Sprint to the left. Please that the lower spoiler is not completely locked down, notice that it is flying along with the relative wind. The upper spoiler is locked all the way back.

During high-speed flight the spoilers drop down or you could say lock out to reduce drag, when the craft returns to hover the spoilers once again rise into the neutral position, yet they will also automatically deploy as the craft is pitched or rolled.

Kelly
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Old Sep 10, 2011, 06:11 PM
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Zhongqiu Jie

Sam,

Maybe we should call your craft a "Taiwan Lantern Ball" or maybe "RC Kongming Lantern"?

Have fun during Zhongqiu Jie.

http://www.dailymotion.com/video/x69...000-ufo_travel

http://www.dailymotion.com/video/x56...l-loy-k_travel

Kelly
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Old Sep 11, 2011, 04:21 AM
DIY Mania from Taiwan
Taiwan
Joined Aug 2011
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Quote:
Originally Posted by corocopter View Post
Hello Sam,

Here are three rough sketches I made, please excuse my poor penmanship as my right hand is still very sore, but I think you’ll get the idea.

Plate number one, shows three rockets, the first rocket has standard size fins with the center gravity head of the center pressure, the second rocket has fins that are approximately twice as large, and you'll notice that the center of pressure moves aft. Of course the center gravity would move at the little aft too since the larger fins has some mass, but I'm just trying to illustrate the concept of the center pressure.

The third rocket has equal amount of fin area ahead of center gravity as well as aft and it is completely unstable, in some respects this resembles the current configuration of the Japanese sphere.

Plate number two, shows four aircraft with varying configurations of horizontal and vertical tail volume's. The first two aircraft illustrate how the center pressure moves aft with an increase in tail volume, thus increasing stability.

The lower two aircraft show various configurations of vertical and horizontal fin area. You will notice the center pressure moves ahead of the center of gravity and the craft becomes unstable, once again this represents in some respects the configuration of the Japanese sphere.

Plate number three, shows two spheres, the first one representing the Japanese sphere, and the second one representing what I think would work best for you.

On the first sphere, please notice that the center of pressure and the center gravity nearly coincide, this represents a marginally stable if not unstable aircraft without the use of a very sophisticated flight controller.

Let's take a look at the second sphere. Please notice that the second sphere has only two small Yaw control vanes. These two small Yaw control vanes would be connected to the flight controllers Yaw Gyro.

To make the craft Yaw to the left or right on its axis you would use the upper two small Yaw control vanes to initiate this movement, after this movement has been achieved, the Yaw vanes would return to a vertical or neutral position. This would represent the least drag above the center gravity

Down below you'll notice 4 pitch and roll control vanes.

Next please notice that the pitch and roll vanes are offset to compensate for all of the Yaw while the craft is in a stable hover. This off-set would be controlled from the transmitter trim only.

Once again the lower pitch and roll vanes would hold this Yaw off-set at all times and it was set by you from the trim tap, this would take a transmitter mix to facilitate this offset. This offset would not be controlled by the Yaw Gyro, it is simply a fixed set trim that you set one time and forget about.

The lower 4 control vanes are for pitch and roll and each has its own Servo. Each Servo would be connected to the flight controller Gyro's for pitch and roll control.

The idea with this craft is to have the very minimum amount of control surface area ahead of the center of gravity, just like in the drawings I showed you about the rocket stability and airplane stability, you want to see the CG ahead of the CP.

Please note that the skirts are directly below and slightly inside the very tips of the propeller where the air velocity is at the maximum. Please notice that the skirts are parallel to the airflow, that is, they are not offset any way. That way the angle of attack of these skirt plates are set to zero. It's very important that the skirts be the within the air stream of the propeller, you want to a surround the skirts with a blast of air from the propeller on both sides of the skirts.

Please note that the small Yaw control vanes at the top are also within the air stream of the propeller, as close to the tips as possible. The velocity of air is the highest just slightly inside and below the tip of the propeller. The optimum size for the Yaw control vanes in my opinion would be quite long and narrow, that way they require very little deflection through a very low angle. This creates less movement of the center of pressure.

Keep in mind, you always want G. before P., center gravity before center of pressure. Just remember when you say the alphabet the letter G. comes before the letter P.

I hope that was clear enough, please let me know if I can add some more details.

Please note, when you open up these photos Sam, if you double-click on the images they will upload to you a very large version of the photograph for you to look at in detail.

Kelly
just back from family outing.
the 2 PDF on VTOL UAV is quite interesting, but could not fully understood,
it takes time to read & note again especially the spoiler mentioned in the 1st one,it's pity that I'm good in Chiness/Japaness but not good enough for English.
the Japanes new info is exactly same as the one that Niceguy posted earlier.
here's feedbacks on the posting,pls correct me if ......
1. CG is alway/better ahead of CP for stability in hover & horizontal fly.
2.Japaness drone is currently CG/CP coincided,that's why sophiscated
controllers needed.
3. 2 vanes + 2 servos ahead of CG with gyro for YAW on top surfaces.size of
2 vanes should go longer/narrower & closer to the tip under airstream.
4. 4 vanes + 4 servos for titch/roll for lower surfaces control.
5. offset the YAW by roll with TX trim.
6. skirt within airstream.
Questions:
--any gyros needed for lower control surfaces on pitch/roll?
--do I need to mix pitch/roll on the lower part?
another good learning,thanks.
Have a nice day
Sam
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Old Sep 11, 2011, 08:13 AM
DIY Mania from Taiwan
Taiwan
Joined Aug 2011
2,006 Posts
Quote:
Originally Posted by corocopter View Post
Sam,

Maybe we should call your craft a "Taiwan Lantern Ball" or maybe "RC Kongming Lantern"?

Have fun during Zhongqiu Jie.

http://www.dailymotion.com/video/x69...000-ufo_travel

http://www.dailymotion.com/video/x56...l-loy-k_travel

Kelly
right, we call it "kongming lantern" in Taiwan,one time a burned out sky lantern dropped down on the field when my scaled RC bird lanched.
nice vids,thanks.
Sam
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Old Sep 11, 2011, 08:27 AM
DIY Mania from Taiwan
Taiwan
Joined Aug 2011
2,006 Posts
Quote:
Originally Posted by corocopter View Post
Spoiler flight dynamics:

Here are four illustrations that I hope will clarify how the spoilers work.

Plate number 4, in this illustration the sphere is in a hover with the relative wind entering equally into the sides and the top of the propeller, please note that both spoilers are horizontal, or you could say both spoilers are in a neutral mode.

Plate number 5, this illustration shows the craft in a gentle roll to the left. The roll control vanes are deflected and now the craft is starting to transverse to the left. Please note the relative wind on the left-hand side of the craft is directed horizontally across the left hand spoiler (in a neutral position) but on the right hand side of the craft the relative wind is coming at a angle that the deflects the spoiler downward. This deflected downward spoiler creates drag and a rotational force that opposes the force of the control vane, thus the spoiler has a tendency to dampen the roll rate to the left.
Plate number 6, this illustrates a roll to the right.

Plate number 7, this illustration shows the craft in a high speed Sprint to the left. Please that the lower spoiler is not completely locked down, notice that it is flying along with the relative wind. The upper spoiler is locked all the way back.

During high-speed flight the spoilers drop down or you could say lock out to reduce drag, when the craft returns to hover the spoilers once again rise into the neutral position, yet they will also automatically deploy as the craft is pitched or rolled.

Kelly
the schetches and your earlier vid explained very well on the functions of the spoilers,I have never seen such smart design in my RC life,what a big discovery from you....
this lead to a new question however,how about the 8 spoilers on the lower part of the Japaness ball drone,do they act as a "loose skirt"
wanted to learn something new from you,or...... squeeze something new out of you???
Have a nice day
Sam
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Old Sep 11, 2011, 11:03 AM
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Quote:
Originally Posted by samwei1950 View Post
the schetches and your earlier vid explained very well on the functions of the spoilers,I have never seen such smart design in my RC life,what a big discovery from you....
this lead to a new question however,how about the 8 spoilers on the lower part of the Japaness ball drone,do they act as a "loose skirt"
wanted to learn something new from you,or...... squeeze something new out of you???
Have a nice day
Sam
Good morning Sam,

I have to agree with you Sam, this Japanese ball is one of the most ingenious devices I've ever seen in the RC world. Not only the fact that it fly so well it's also designed to roll around on the ground and evade its own capture or demise.

I think it's too difficult to try to copy all of the features of this craft so I've tried to eliminate as many components as possible for you to try out.

Sam I see no indication of any spoilers on the lower half of the sphere, I have attached the two best photographs I've seen so far of the device and the only thing I can see on the lower half of the sphere are the pitch and roll vanes, and the skirts. After watching the movies of the craft in flight I see no indication that the skirts are free floating, but I may be wrong. Perhaps they tilt a little bit to make fine adjustments of the angle of attack, but I see no evidence of this, maybe some other forum readers here or you can see some evidence of movable skirts? At this time I would disregard any ideas about movable skirts or spoilers on the lower half of the craft.

I can tell you there are no spoilers on the lower half of the craft with certainty. The spoilers will only work in conjunction with a propeller, the propeller creates the inflow they are that activates the spoilers into the horizontal position, and without a propeller they would have no function.

Okay Sam, I have figured out how to simplify your version of the sphere, few parts, less weight, I'll give you a few details in the next posting.

Kelly
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Old Sep 11, 2011, 11:53 AM
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Joined May 2010
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Quote:
Originally Posted by samwei1950 View Post
here's feedbacks on the posting,pls correct me if ......
1. CG is alway/better ahead of CP for stability in hover & horizontal fly.
2.Japaness drone is currently CG/CP coincided,that's why sophiscated
controllers needed.
3. 2 vanes + 2 servos ahead of CG with gyro for YAW on top surfaces.size of
2 vanes should go longer/narrower & closer to the tip under airstream.
4. 4 vanes + 4 servos for titch/roll for lower surfaces control.
5. offset the YAW by roll with TX trim.
6. skirt within airstream.
Questions:
--any gyros needed for lower control surfaces on pitch/roll?
--do I need to mix pitch/roll on the lower part?
Sam
Sam,

Yes you have items 1 through 6 correct, I would like to go over item number 1 a little bit more.

For hover the CG should be closer to the CP, for high-speed flight the CG should move ahead of the center pressure. The exact location of both of these will only be able to be determined by flight testing without sophisticated computer modeling, or wind tunnel testing. In the PDF that you found of the Japanese sphere one photograph showed a version of the sphere that did not have a motor or propeller attached, I suspect that was a wind tunnel model. Obviously they have enormous financial resources at their disposal to develop this craft.

Remember, in the patent it talks about having a movable center of gravity using a Servo to move the battery or weight to adjust the center gravity. So when the craft could go into hover the Servo would lower the battery to lower the CG closer to the center pressure, conversely when the craft is tilt over into high-speed flight the Servo would raise the battery and pull the center gravity upwards away from the center pressure increasing the lateral stability of the craft in forward flight.

I think the spoilers were developed to do away with the complex electro-mechanical device which included a Servo, the movable weight and some sort of mechanism to detect the tilting of the craft plus a complex algorithm in the flight computer to calculate this CG position. The spoilers would function much more rapidly and precisely, they require no electrical power or computational programming from the flight data computer.

To finish up item number one, you were correct, but I just wanted to make sure you understand we don't know exactly what that relationship will be regarding the center gravity and center pressure until after you fly the craft, and even then it's extremely difficult to know the exact location of the center pressure. In general terms you need to have the center gravity ahead of the center pressure.

Items number 1 number 3 and number 4 are correct.

Item 5. I need to clarify, you are correct, set the Yaw with the roll and pitch control vanes. This can be accomplished either mechanically by simply clamping the control surfaces to the carbon rod and adjusting the onset than tightening a screw, using this method you only need to servos 1 for the pitch control vanes, and 1 Servo for both roll control vanes. The second option would use 4 servos, and you control (set and forget) the yaw off-set from the transmitter trim, this would require a mix. Last night I came up with a way to simplify this idea and I plan on drawing a sketch for you today to illustrate all of this in detail.

Item number six is correct.

Your two questions:

1. You need one Gyro for the two small Yaw control vanes, one Gyro to control the pitch control vanes, and one Gyro to control the roll control vanes. My guess is that a KK multi-rotor controller would work very nice, since it has three axis controls, with three gyros. Hobby King sales cheap quad controller, for $30, maybe that would work.


2, For pitch and roll control no mixing is required, if you use four servos, you could have a mixed set up to just control the fixed trim to control the Yaw offset. I've come up with a simple way to eliminate this mix. I want to keep it very simple!

Okay I've come up with a way to make this craft work with just three servos,1 BEC, 1 motor, 1 propeller, 3 axis Gyro, and battery.

Basic new control idea:

The small anti-torque vanes can be controlled with one Servo, setup like you would strip ailerons on RC aircraft.

The pitch control vanes, and the roll control vanes only need one Servo each, by connecting the individual vanes to the carbon shaft with a clamping mechanism you could set the Yaw control off set manually just by releasing the clamping pressure with a simple screw, turning the vanes to the appropriate angle, and tightening the screw.

With this arrangement you only need three servos total (1 for yaw control, one for pitch control, one for roll control). It saves a great deal weight and you only need a simple four channel radio.

Later today I'll draw sketches of this new design, the basic layout is the same as before the only details that have changed our how to set up the linkages on the control surfaces.

Keep asking questions, there’s still plenty of juice to ring out of me.

Kelly
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Old Sep 11, 2011, 12:48 PM
DIY Mania from Taiwan
Taiwan
Joined Aug 2011
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Kelly
many thanks for all the good efforts,things are getting more exciting.
I'll start modifying the drone tomorow.
best regards.
Sam
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Old Sep 11, 2011, 01:43 PM
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To remove confusion:

Sam,

Look at my post #151, open the photos and look at plate #4. The pitch/roll controll vane is not exactly correct for hover. In reality it would have some tilt to compensate for the yaw (torqure) of the motor. I made it perfectly 0 degrees defection so as not to confuse the issue. I was trying to show how the spoilers work. I'll have more to say how this all works later today.

I'm excited to see how this all works out too

Kelly
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Old Sep 11, 2011, 06:49 PM
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Taiwan Ball #1

Good afternoon Sam,

Attached is a sketch of the Taiwan Ball #1. I configured this sphere to have only three servos so I need to talk about how the Yaw control vanes are hooked up to one Servo. Attached are two photos of some stripped ailerons and the required linkage, if you use that set up you'll only need one Servo to control both Yaw tabs.

The pitch and roll control vanes need to be clamped to the torque tube. I made a crude sketch of how the clamp can be made out of a small piece of wood with one screw, that way you could release the pressure, adjust the vanes to the proper angle and then tighten the screw back up.

If you clamp the pitch and roll control vanes to the torque tube, you only need one Servo for each axis, and you don't need to have a mix set up in the transmitter.


Theory of flight operation:

Here's how you set this thing up to fly, adjust the pitch and roll control vanes to have an off-set of approximally 12° each, they don't have to be perfect just close. On the initial flight test you want to set it up so that the Yaw control Servo is disconnected from the receiver, and both Yaw control vanes are hanging perfectly straight down and locked so that they won't move. Next, while holding the craft in your hand and applying power watch to see if the craft spins clockwise, if it turns clockwise increase the off set angle on all four lower vanes. Conversely if the sphere spins counterclockwise reduce the off set angle on the vanes. Now you have the basic setup to control the Yaw (torque) of the electric motor.

Now plug in the Yaw control Servo into the receiver and test fly the craft. What you're aiming for is to have the Yaw control vanes hanging vertically in a stable hover, when you need to yaw the craft left or right or suddenly add power or reduce power, the small yaw control vanes will deflect and make the required heading change then return to the neutral (vertical position). By using these small yaw vanes you get a very fine scale change in the yaw motion, reducing the hunting effect.

Keep in mind that during hover your going to always need the same amount of counter torque force created by the offset in the pitch and roll vanes. This is a fixed moment (force) as long as you don't change the propeller or remove or add any additional weight to the craft. You will never have to change this basic offset setting. The TurboPlane that I worked on for many years works like this very successfully. You only need very small Yaw control tabs to initiate the required force for a selected input from the pilot or from the flight controller yaw gyro.

Let me know if you have questions please.

Kelly
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Old Sep 12, 2011, 02:05 AM
DIY Mania from Taiwan
Taiwan
Joined Aug 2011
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Quote:
Originally Posted by corocopter View Post
Good afternoon Sam,

Attached is a sketch of the Taiwan Ball #1. I configured this sphere to have only three servos so I need to talk about how the Yaw control vanes are hooked up to one Servo. Attached are two photos of some stripped ailerons and the required linkage, if you use that set up you'll only need one Servo to control both Yaw tabs.

The pitch and roll control vanes need to be clamped to the torque tube. I made a crude sketch of how the clamp can be made out of a small piece of wood with one screw, that way you could release the pressure, adjust the vanes to the proper angle and then tighten the screw back up.

If you clamp the pitch and roll control vanes to the torque tube, you only need one Servo for each axis, and you don't need to have a mix set up in the transmitter.


Theory of flight operation:

Here's how you set this thing up to fly, adjust the pitch and roll control vanes to have an off-set of approximally 12° each, they don't have to be perfect just close. On the initial flight test you want to set it up so that the Yaw control Servo is disconnected from the receiver, and both Yaw control vanes are hanging perfectly straight down and locked so that they won't move. Next, while holding the craft in your hand and applying power watch to see if the craft spins clockwise, if it turns clockwise increase the off set angle on all four lower vanes. Conversely if the sphere spins counterclockwise reduce the off set angle on the vanes. Now you have the basic setup to control the Yaw (torque) of the electric motor.

Now plug in the Yaw control Servo into the receiver and test fly the craft. What you're aiming for is to have the Yaw control vanes hanging vertically in a stable hover, when you need to yaw the craft left or right or suddenly add power or reduce power, the small yaw control vanes will deflect and make the required heading change then return to the neutral (vertical position). By using these small yaw vanes you get a very fine scale change in the yaw motion, reducing the hunting effect.

Keep in mind that during hover your going to always need the same amount of counter torque force created by the offset in the pitch and roll vanes. This is a fixed moment (force) as long as you don't change the propeller or remove or add any additional weight to the craft. You will never have to change this basic offset setting. The TurboPlane that I worked on for many years works like this very successfully. You only need very small Yaw control tabs to initiate the required force for a selected input from the pilot or from the flight controller yaw gyro.

Let me know if you have questions please.

Kelly
3 servos & 3 gyros,12degree on pitch/roll testings
I'll use headlock gyro on YAW.
one at a time,I'll do single motor on next stage.
have a nice day
Sam
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Old Sep 12, 2011, 08:34 AM
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Balance Sphere:

Sam,

Yes that is all correct.

It is critical that you adjust the side to side (lateral) balance of the sphere.

You must hang the craft with a string from the propeller shaft. You have to construct a balancing indicator device. I'll show how to make this later this morning.

It is Extremely Important that this balancing be accomplished with great accuracy!!!!! The better the job the better the hover.

More later this morning.

Have fun, looking forward to flight testing.

Kelly
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Old Sep 12, 2011, 08:46 AM
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Sam,

If you use the counter rotating propeller/motors setup, reduce the offset to 3 degrees or maybe less on all pitch and roll vanes. Test fly.

In theory you should need 0 degrees, but you may find that it needs off-set going the other way. It just depends upon the friction within your system, or current draw from each motor. One motor may put out more power and you'll find a torque represented in a yaw forces. I don't know which way the craft will spin in this cases. Just perform the preflight test I mentioned and set the vanes as required.

When and if you choose to use a single propeller, then you'll need to add considerably more off-set.

Edited for clarity 5 minutes after posting.

Kelly
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Old Sep 12, 2011, 09:01 AM
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Please reread my last post, I had to edit it for clarity.

Kelly
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Old Sep 12, 2011, 11:51 AM
DIY Mania from Taiwan
Taiwan
Joined Aug 2011
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Kelly
got your notes,thanks.
I'm convinced this project will be fully accomplished by end of this month.
best regards.
Sam
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