2 bladed pusher flies!

[mnowell129]

here's the latest.
A couple initial mishaps but
6 successful flights this afternoon.
comments welcome.
mickey

[rcflyerfl]

Mickey

Very colorful too. Should be easy to see in your neighborhood.

Jim

[dougmontgomery]

Mickey, Your killing me.......That is so cool as a pusher and the Pilot definitely adds some character. Do you ever sit still.

How does well does it track with the shorter tailboom?
I almost bought a Himax outrunner tonight, which one is that?
What size prop?
How many cells?
Doug

[mnowell129]

Mickey, Your killing me.......That is so cool as a pusher and the Pilot definitely adds some character. Do you ever sit still.

How does well does it track with the shorter tailboom?
I almost bought a Himax outrunner tonight, which one is that?
What size prop?
How many cells?
Doug
no I never sit still. My other hobbies are hang gliding, photography,
and boy scouts.
It flies fine with the shorter tail boom. In windy conditions (all I've had)
you have to keep a little power on to keep rudder authority, otherwise it
is a little twitchy, but not bad.
Himaxx 2812-850
APC 10x4.7 SF
3 Cell Shulman (the blue one) 1200 MAH 12C rating (this battery is the BOMB!)
This motor goes like blazes in this setup, full power is essentially vertical.
Do you want one?

video when possible, but it flies just about like G3PO but with nose up trim under power, which is actually kinda useful, especially when adding power to turn as it kinda fixes the trim for you when you add power...

The really cool part is the prop is close to the main shaft so it makes a noise not unlile a real prop/engine.. sounds way cool when flying....
mickey

[gyronuts]

Hi,
Excellent job. Where do you find the time. I have only just got the complete head assembly from a hummingbird , through ebay, for my version of your G3po.... but off on holiday this weekend for one week.
Now you produce the version of a gyro I really want!!!
Keep up the good work I certainly appreciate your efforts/videos and reports...they keep me sane. Bill

[mnowell129]

Hi,
Excellent job. Where do you find the time. I have only just got the complete head assembly from a hummingbird , through ebay, for my version of your G3po.... but off on holiday this weekend for one week.
Now you produce the version of a gyro I really want!!!
Keep up the good work I certainly appreciate your efforts/videos and reports...they keep me sane. Bill
The time comes from
1) no wife
2) Don't watch tv
3) Stay out of bars
4) one kid in college, the other one in high school
5) I build really, really, fast when prototyping
( this model about 4 hours start to test flight, since I stole the head off
the other one and didn't have to build blades).
I get the feeling I'm going to have to really draw the plans for this one as everyone that sees it starts drooling and fantasizing about putting a little yellow cowl with rocket pods on it ( 007 theme begins to play in the background).....
mickey

[dougmontgomery]

Mickey,
Well Looks like I will be buying the himax outrunner. I really like the thought of hiding the prop behind the mast so the pilot is kind of hanging out there. Kind of like when I had My Quicksilver MXL ultralight.(60 hours) I will look forward to the plans. Then I will transfer over head assembly from G3p0,What is the new ones name? "G3P0-007" Video Yet? Keeep the mind going Mick, whats next.........Doug

[mnowell129]

Mickey,
Well Looks like I will be buying the himax outrunner. I really like the thought of hiding the prop behind the mast so the pilot is kind of hanging out there. Kind of like when I had My Quicksilver MXL ultralight.(60 hours) I will look forward to the plans. Then I will transfer over head assembly from G3p0,What is the new ones name? "G3P0-007" Video Yet? Keeep the mind going Mick, whats next.........Doug
Video soon.
not sure about what's next. I'm thinking two bladed, no flybar with collective pitch, got the parts ordered anyway....
Name of new model : Backward Engine GIro, "BeGi", Pronounced Bee Gee.

[mnowell129]

Video of BEGi posted at
http://www.mickeynowell.com/id9.html
takeoffs, touch and goes, dead stick, tight low altitude
circles, low pass, etc.
enjoy.
mickey

[Keith43221]

The time comes from
fantasizing about putting a little yellow cowl with rocket pods on it ( 007 theme begins to play in the background).....
mickey

I belive you are refeerning to "little nicky" she was compact and could be built in a half hour with Q's team. That sure is a pretty a mumm.. heilplane.

[gyronuts]

The James Bond gyro was "Little nellie" I think. Bill

[AustinTatious]

Wow man, thats uber sweet... Pusher models are tough.... looks liek that one has a lot of climb power! too cool man!

Wanna go the next step.. make it full collective witha jump start!

[mnowell129]

Wow man, thats uber sweet... Pusher models are tough.... looks liek that one has a lot of climb power! too cool man!

Wanna go the next step.. make it full collective witha jump start!
Thanks.
It will really climb, its hard to see just how much in the video.
Always another challenge right... I'm working on the full collective idea
in my head.....

[dougmontgomery]

For one I need a camera person like that, stays on the Begi well.

For two- I watched your video twelve times because it took an hour to download on my dial-up, yea I know dial-up.

I really like the ascent the Begi has and the spot landings, that of course if you still had some juice in that battery left.

Are you getting better run time with the out runner? Not that I could concentrate any longer but I really like it as a pusher, (kinda hides the thrust maker)

Is that the newly multi-purpose put on any autoGyro servo mnted tail assy. I like that idea a lot, just plug and play.

Once again Mickey I sure love your craftmanship and ingenuity. Doug

[mnowell129]

The runtime is pretty good on the outrunner, seem to be longer than the standard himaxx internals, they make good torque with a big prop so they work for the gyro. I haven't compared side by side yet so this is just gut feeling and may be totally wrong.
The tail assembly is just like g3po with the servo right at the back. I did it this way because i was concerned that the pull pull lines might get sucked into the prop. This way I just used a long servo lead and taped it to
the bottom of the boom where it stays out of the way.
I don't think this is a great idea for the longer models because it puts a
1/2 ounce way at the back and this turns into 4 ounces of nose weight or that much longer nose. I got away with it here because the tail is short.
I'll probably switch the servo back to the front and run the pull pull
in plastic tubes. I've already stripped two sets of gears with the
solid pushrod. The pull pull lines take up the shock better.
mickey

[dbeamon]

I would realy like the plans for your bird ..

[mnowell129]

I would realy like the plans for your bird ..
You'll have them soon.
In the mean time the tail assembly, rotor head parts, rotor head
assembly, anti-rotation link, and servo installation is all identical to the G3PO. Also identical to
G3PO , the landing gear mount, landing gear struts and wheels,
except the angle is about 170 degrees instead of 125.
These drawings are posted on rcuniverse/helicopter/autogyro under "how to build G3PO. The only differences are basically main mast height and motor mount location. So the only new drawing will be a scale drawing of the
actual "chassis" all other things being equal. The pusher layout drawing on
those pages is pretty close to what I did. But I will document the actual dimensions and angles of the one I have flying a few days.
mickey

[dbeamon]

How mutch negative are you running ????

[mnowell129]

How mutch negative are you running ????
Aerobalsa blades. They are set at about 4-5 degrees negative. The way I arrive at that is to start with them at 0, spin by hand, taxi and then see if it spins up. Then keep adding negative until it spins up reliably. This is the advantage to using the steel blade straps, you can adjust on the pitch until it is just right.
The slowest, least power flight is the least negative you can get away with and still spin up. However at that setting, you can't let the rotor unload or slow down in flight because it takes a long time to spin back up. If you want more margin, put more negative in than the minimum. It will spin up faster and fly a little faster but won't get into trouble as fast. I set mine on the razor edge because I like to fly really slowly in the street in front of the house. the videos on my website illustrate....

Set at the minimum a hand launch is still easy to do as well.



mickey

[dbeamon]

thanks for the replie on the negitive in the blades, Just one more ??? how long and wide are your blades ?????? Just want to get it right ,

[mnowell129]

thanks for the replie on the negitive in the blades, Just one more ??? how long and wide are your blades ?????? Just want to get it right ,
15" by 1.5" inches.
they came from aerobalsa.com.
They are cut down to 15" inches, weighted and covered with monokote trim.
mickey

[mnowell129]

Have flown with 16" blades on BEGI with good results. Steamed in about 10 degrees of twist also. Returning the original 15's to G3PO.
Two experiments now prove to me that twisted blades are well worth the effort.
mickey

[David A Ramsey]

twisted blades are well worth the effort.
mickey

Hey Mickey......... assuming twist is washout. Sounds like a good idea as this would counteract washin that could occur during autorotation speed.

Is that the idea?

David

[mnowell129]

Hey Mickey......... assuming twist is washout. Sounds like a good idea as this would counteract washin that could occur during autorotation speed.

Is that the idea?

David
Actually "washin". The tips are more positive than the roots. Tips are set
at about 0 degrees, roots at about -10. Exactly opposite from a propellor.

[David A Ramsey]

Actually "washin". The tips are more positive than the roots. Tips are set
at about 0 degrees, roots at about -10. Exactly opposite from a propellor.

Wouldn't we be stalling the tips??? Hummm. We go negitive to "0"

Gotta think this through!

[mnowell129]

Wouldn't we be stalling the tips??? Hummm. We go negitive to "0"

Gotta think this through!
Go back to the vector diagram of the local airflow on any blade element. The tips have the highest velocity, thus the incoming airflow is roughly roughly parallel to the tip path plane. The forward aircraft velocity and back tilt contributing very little. At 500 rpm a 1.5 foot rotor tip is moving 80 feet per second, at 20 mph (30 fps), the forward flight component of velocity is only about 1/3 the magnitude of the tip speed and this is diminished by the sine of the tiltback angle (sin(15) = .25) .25 * 30 = 7.5 fps. Thus the local angle of attack is the inverse tangent of 7.5/80 or 5 degrees. So a clark y rigged at 0 geometric (4 degrees true) sees 9 degrees local true angle of attack.

Inboard toward the root, the velocity due to rotation goes to zero.
The same math applied to the rotor section at 4" from the hub is
angular velocity component = 500/60 * 2 * pi * 4/12 = 17 feet per second. We already figured the airflow due to the forward velocity and tiltback to be 7.5 fps. Thus the local airflow is inverse tangent of 7.5/17 = 23 degrees. So for this section to be at the same angle of attack as the tip it needs to be rigged to -14 degrees. It is more than certain that a blade section at +23 degrees is stalled. (I've ignored the parallel component of forward velocity because it adds on one side and subtracts on the other, to make the analysis simple.)
Twisting the inboard blade sections downward puts them at the same angle of attack as the tips with respect to the relative airflow. This make the inboard section actually produce some useful lift or if you put a little too much negative it actually generates some torque to turn the rotor. More than likely with straight rotor blades (I'm willing to bet dinner at Macaroni Grill on this one if anybody wants the bet), most model gyros are flying with the inboard section stalled and just producing drag and a retarding torque tending to slow the rotor down. When you twist the root sections negative you make the inboard section actually contribute.
The problem with twist is that it only is really perfect for one rpm/airspeed combination. But some twist is a much better compromise than no twist. It gets much more of the blade working for you.
My totally scientific method of twist is to hold the blades in steam and twist them until it looks about right, the famous TLAR method. But its 10-12 degrees, based on many hours staring at a pitch gauge on a helicopter and developing a calibrated eyeball.
I can swap twisted blades for untwisted and immediately see less power required to fly level, faster spin up, and lower minimum airspeed.
Food for thought for those trying to fly with very little power, like indoor models.
mickey

[David A Ramsey]

Well now, there you go! Ya got such a way with words Mickey!

Gonna skip the first paragraph cause the second one does the job for me. Glad to know your doing the sceintific steam twist method as that's what I'll go for.

An interesting twist I'll have to consider.

Thanks Mickey.

[David A Ramsey]

Actually "washin". The tips are more positive than the roots. Tips are set
at about 0 degrees, roots at about -10. Exactly opposite from a propellor.


Would it be correct to say this is because a propeller is producing a force and an autogyro rotor is reacting to a force?

[mnowell129]

Would it be correct to say this is because a propeller is producing a force and an autogyro rotor is reacting to a force?
Maybe. But not really. A propellor and a rotor both have twist for the same reason, that is that a rotating wing sees a variable angle of attack with respect to distance from the hub. Twist just aligns each little segment with the local airflow. If you look at a twisted rotor from the bottom it actually has the same twist as a prop, but the airfoil is on the bottom.
mickey

[David A Ramsey]

Maybe. But not really. A propellor and a rotor both have twist for the same reason, that is that a rotating wing sees a variable angle of attack with respect to distance from the hub. Twist just aligns each little segment with the local airflow. If you look at a twisted rotor from the bottom it actually has the same twist as a prop,

but the airfoil is on the bottom. ???

mickey

Either I'm comprending too slow, or your writting too fast: I'm looking at a prop that has a high angle of attack at the root with pitch reducing as it aproaches the tip.

For our gyro blade, you're talking about negative pitch at the root going to "0" degrees at the tip. Right?

Now if I look at a twisted rotor from the bottom... it actually has the same twist as a prop............ But backwards maybe???

David

[mnowell129]

Either I'm comprending too slow, or your writting too fast: I'm looking at a prop that has a high angle of attack at the root with pitch reducing as it aproaches the tip.

For our gyro blade, you're talking about negative pitch at the root going to "0" degrees at the tip. Right?

Now if I look at a twisted rotor from the bottom... it actually has the same twist as a prop............ But backwards maybe???

David
Yes, negative pitch at the root, tending towards 0 at the tip. I say tending because you may still have a little negative at the tip, but much less negative (more positive?) than the root.
If you take a prop, turn it over (front of prop towards the ground) and hold it in the air as if it were a rotor, It has the proper twist for a gyrocopter rotor, for clockwise (viewed from the top) rotation. The tips are near flat pitch, and the root is very negative. It would fine for a gyrocopter rotor except the curved part of the airfoil would be facing down at the ground and do a very poor job making lift. Further, even though it is the right "kind" of twist it is too much. The twist in a prop is designed for a relative airflow of 90 degrees, a gyro rotor 15-20 degrees. But the general twist direction is like a prop held upside down (for CW rotors, you'll just have to imagine for CCW rotors).
I c o u l d p r o b a b l y w r i t e
s l o w e r d o e s t h i s h e l p ?
m i c k e y

[David A Ramsey]

I c o u l d p r o b a b l y w r i t e
s l o w e r d o e s t h i s h e l p ?
m i c k e y


Well now it looks encrypted!

I do follow the principle, but ya gotta keep it simple.

I enjoy your input to this forum. Even sneek over to the other place, once in awile, to see what you're up to.

David

[mnowell129]

Well now it looks encrypted!

I do follow the principle, but ya gotta keep it simple.

I enjoy your input to this forum. Even sneek over to the other place, once in awile, to see what you're up to.

David
I originally had bigger spaces between the words, but the stupid forum software takes all redundant spaces out. Makes it tough to put column data in.....
Sorry about overcomplicated explanations i'll try to
eschew obfuscation in future posts. I'm just so happy to have
someone to discuss thing with. Few of the locals care about
the theory.
I cruise both forums, I don't get the forum allegiance thing.
There's a third by the way, rc-hangout or some such with an Autogyro thread that gets about one post a week. But Hal Debolt is the local expert.
mick

[David A Ramsey]

i'll try to
eschew obfuscation in future posts. I'm just so happy to have
someone to discuss thing with. Few of the locals care about
the theory. mick

Hummmm, Preperation H should help with that.

I don't feel anyone who has an autogyro, having read your input, doesn't have a better grasp of why and how their autogyro works.

Without your input, I'd still be searching.

David

[DBa]

Without your input, I'd still be searching.

David

Yup me too :D .

By the way a great thanks to david and mick. Reading ur replys help me a lot.

Regards

DB.

[mnowell129]

Yup me too :D .

By the way a great thanks to david and mick. Reading ur replys help me a lot.

Regards

DB.
I'm glad you guys are benefitting. And David your comments are very flattering. I spent a long time collecting material, reading and studying. It would be a crime not to write it down so someone else couldn't benefit.
mickey

[David A Ramsey]

I'm glad you guys are benefitting. And David your comments are very flattering. I spent a long time collecting material, reading and studying. It would be a crime not to write it down so someone else couldn't benefit.
mickey

Well Mickey, I ain't tryen to flatter ya! I just have a healthy respect for those that have a grasp of essentials that I'm missing. I admire (now this doesn't necessarily mean you) a clear headed thinker! I like concepts that are presented and supported.

David

[mnowell129]

Well Mickey, I ain't tryen to flatter ya! I just have a healthy respect for those that have a grasp of essentials that I'm missing. I admire (now this doesn't necessarily mean you) a clear headed thinker! I like concepts that are presented and supported.

David
Ok I won't be flattered then.
I don't know that I've ever been accused of being anywhere near clear headed.
The interesting thing is, all this theory was out there in bits and pieces. Rotor theory, reynolds number, following rate, etc. It was just scattered all over different references, most of it model helicopter related. Some of it was
gleaned from a column in Rotor and Wing Magazine called Helicopter Aerodynamics by Ray Prouty, now available in book form. Some came from John Drake's model helicopter design book, some from Don Lodge's Model helicopter design book, and some from an article from the AIAA Student Journal in 1981 by John Burkham (Designer of the Penni indoor rubber powered helicopter, available from Peck Polymers). There are other references too on the web but all written about helicopters. When I started studying gyrocopters I was told that helicopter theory doesn't apply. Turns out it does, a rotor is a rotor. The special case of autorotation provides some new twists but the basics of coning/advancing blade/following rate math don't care whether the rotor is being turned by a motor or not.
I'll make you a bibliography if you want it, but unfortunately most is out of print. Some items are available from abebooks.com. I can copy the Burkham article if you care to read some of it.
mickey

[David A Ramsey]

From 1987 throught 1999 I was heavily into helicopters and your references to Prouty are familiar to me. Burkham? Wait a minute, I have the drawing of his "PENNI" that was printed in American Aircraft Modeler in 1970. I even built one. It was fairly stable, but duration of the rubber motor was too short. James Wang also has provided a lot of input.

As I think back to the trim problems I was having with my little fixed head gyro, I realize I had the information I needed to fix it, just wasn't thinking hard enough. Must have been thinking helicopter rotors had nothing to do with gyros. Yup a rotor is a rotor!

A thread with reference would be good, but you've already provided so many. I wonder if anybody else thinks it's needed???............ Forum has been quiet lately.

[mnowell129]

I've noticed the quiet threads. Even on RCU.
A reference thread might be easy enough. The crowds wither when you start talking theory however. It's down to me and you and a couple other readers. Pity too, because a little theory is really important to gyrocopters to help you start making good design decisions.

I know some of the guys are busy readying for Spring Hill in about 2 weeks.
I have to put G3PO back together since I robbed the head for BEGI.
I'm thinking of putting together a RTF G3PO to take to Spring Hill to
see if anyone wants an RTF model. I figure I can do it for about $450 with
everything (radio, brushless motor, speed control) except battery already test flown. I'd include at GWS transmitter that I'd give a refund on when the radio setup got transferred.
Ya think there's a gyro flyer so frustrated he might take a RTF model home with him?

[David A Ramsey]

I'm thinking of putting together a RTF G3PO to take to Spring Hill to
see if anyone wants an RTF model. I figure I can do it for about $450 with
everything (radio, brushless motor, speed control) except battery already test flown. I'd include at GWS transmitter that I'd give a refund on when the radio setup got transferred.
Ya think there's a gyro flyer so frustrated he might take a RTF model home with him?

If you get a good spectator turnout and a fellow who sees and feels the magic and appreciates the equipment he's getting.......There might be one.
Actually I think you'll get a lot of interest till they hear the price. Might be a good idea to have a good supply of plans to sell at your cost plus a couple of bucks for your labor. Do you sell Blades? Or where can I get Blades ready made? Do you make a kit? How much? OOOH, that much. I'm sure you'll get a lot of questions.

Lots of modelers seem to be curious about Autogyros, but, as is well known, only a small precentage ever take up the challenge. Is it the rotor blades, the simple mechanics, or even the required use of rudder input to turn, rather than bank and yank?

The smaller version of my current gyro is an attempt to offer a very simple design using an S2 IPS brushed drive, GWS standard micro RX, 2 Blue Arrow micro servos, CC Pixie7P ESC and a 2S 350-700mAh Lipoly battery. I would have liked to use a small NiMi battery, but the design may not take the extra weight. I also want to see if a simple Jadelski (sp?) wing shapped rotor blade will work. ie: no curves in the airfoil. And perhaps a 2 bladed fixed rotor rather than 3. I'm trying to make it simple and inexpensive to produce. If it all works out I'll see if Flying Models Mag. will publish it.

David

[Demon-Leather]

I've had this old kit around forever...."Little Nellie" was actually a dolled-up Wallice WA-116 experimental military autogyro. I was hoping to make a flying scale model of it.. looks like You beat me. I was going to use a GWS IPS ball bearing geear drive housing on mine for a very free-spinning rotor. I'd really like to see the detail of your rotor head... I was going to use the same method Arizona Autogyros uses in affixing their blades for the self-correcting "flapping" effect, but if a fixed metal blade attachment will work, it's even better. Also, a diagram of the blade "negative pitch" would be helpful if you'd like to post one. GREAT Job! >tips hat< Bob

[GWS4CEO]

GWS started this "Little Nellie!" design to be RC about 4 years ago. ;)

But this project not being finished. Shall we carry on? :confused:

[Demon-Leather]

Good to hear from You again, Mr.Lin! :D There is only one answer to that question: YES! YES! YES! YES! YES! YES! YES! YES! YES! YES! YES! YES! YES! YES! :D :D :D :D

I believe a "Little Nellie" autogyro would surpass even the GWS Tiger Moth in sales! :eek:
With all the extra money you make, you could send me LOTS of GWS equipment for "Research and Development!" :rolleyes: hehe! :D Glad to see GWS is involved in designing "different" types of flying machines! :D Again, it's very good to hear from you, Mr. Lin! Bob
PS: You should call it something else besides "Little Nellie" though, as I believe they would make you pay for that name! :( Bob

[David A Ramsey]

Enjoyed the fun fly video of your pusher. Just love the contol!

Looks like the event made your weekend!

David

[mnowell129]

Enjoyed the fun fly video of your pusher. Just love the contol!

Looks like the event made your weekend!

David

Thanks, it made a pretty good friday. No real crashes, even got some in flight video....
mickey

[Tram]

Anyone else doing autogyro's like this??

[David A Ramsey]

I'm gonna try Mickey's G3P0 first. I plan to use an E-sky collective head with a 90 degree swashplate. So far I'm having trouble gathering all the parts from one source.

David

[Demon-Leather]

I WANT to... but everytime I try & read the theory on 2-rotor design,.. about coning, leading, trailing, pitch, collective, blade twist,etc, etc, etc... My mind slowly turns to corn mush, then sucks up inside itself... :( :confused: Can anyone write "2-bladed rotor head design for dummies? Sounds like great reading to me! :rolleyes:
I Mean.. I'm not dumb,(I don't think) I've designed many sucsessful models,.. just this rotor & blade stuff gets a bit long-winded.
Does anyone have a 2-bladed head that works and they are willing to share?
I can build an engine that can get you down the 1/8th mi drag strip in record time... without nitro... but you start talking flow & volume theory vs internal pressure under load, CFM @ maximum rpm, etc... I'm thinkin' "what a nice day to fly..what do I have on the charger?" :rolleyes: is that AADD? :confused: Show me a working design, how it's constructed, and I can build it... I MAY even be able to make it better.. But, if I have to wade through a lot of theory,..."What a nice day for flying"... "what do I have on the charger?" :p Bob

[David A Ramsey]

Hey Bob, don't let the theory part get ya down. At some point the theory may come in handy. The neat thing about Mickey's work is that he has a couple of great working designs that are supported by theory. Using micro heli parts from the swashplate up simplifies the headaches in a direct controlled head. Personally I find the details quite enjoyable. The explinations may seem long winded, but I take this as a man deeply interested in conveying ideas for an autogyro that works so well.

David

[Demon-Leather]

I wasnt really complaining..(well I guess I was) but it wasn't meant with malace. I've never fooled with helis (want to someday)and know the "idea" behind the control.. I'm just wondering if anyone out there can show how to fabricate & assemble the parts for a home-made version... kind of a step-by-step do-it yourself thread from start to finish. I'm really good at fabricating with "on-hand" materials. Heli-parts,.. micro, or otherwise, can be REALLY expensive, and guys like me on a "shoestring-budget" sometimes get left out in the cold. :( I'm going to do a "multi-rotor blade" Top secret project in the near future... should be Waaaay-kool if it works! :D I can pretty much use Arizona Autogyros technique on that one, using weighted blades, and a GWS b/b gearbox for a free turning rotor head assy. Along with some carbon fiber plates to give a bit of "flex" to the blades (there's that "coning-thing" again...:rolleyes: ) But the 2- bladed rotor head seems to be more complex, reading the threads about it. "If you show me... I can build" sort of thing..:D Bob

[David A Ramsey]

I:( I'm going to do a "multi-rotor blade" Top secret project in the near future... Bob

Hey Bob; I understand "hands on" and "shoestring budgets". My little fixed head gyro was a result of gathering all the physical information I could to build a small, light, cheap and simple machine. However, due to the power needed to fly, the brushless motor and ESC ruined the cheap part. Rotor wings and fixed wings, however are very different. I started my thread as a way to understand the forces acting on a rotor. Mickey's explinations were a great help. http://www.rcgroups.com/forums/showthread.php?t=302448

For myself, I feel Mickey's G3P0 is a great "step-by-step-how to" for a "hands on" building project. I feel the project is too good to pass up.

Your "multi rotor blade" project will be something to watch for, should you decide to share it, but the 2 bladed rotor head theory will still be part of it. This forum should be a great source for your project.

Oh, as a specific item, I don't think to much about the coning angle stuff.

David

[David A Ramsey]

Getting serious about getting your G3PO together now.

Question:

The inner race of the GWS and E-sky's swashplate has 2 different opposed arm lengths. In your photos I see you're using the shorter arms. Does it make much difference which ones are used?

David

[mnowell129]

Getting serious about getting your G3PO together now.

Question:

The inner race of the GWS and E-sky's swashplate has 2 different opposed arm lengths. In your photos I see you're using the shorter arms. Does it make much difference which ones are used?

David
I use the longer arms. It gives more control.

[David A Ramsey]

Fair enough! Thanks

[foamkiller]

:) are there plans yet

[mnowell129]

Nope, but soon. Almost done with the GWS pt17 conversion.
Pusher next
:) are there plans yet

[max z]

Nope, but soon. Almost done with the GWS pt17 conversion.
Pusher next
Mickey, I have ordered the rotor head parts, and I will be starting on a BeGi lookalike pusher soon, based on the sketch you published earlier. Are you making any serious changes lately?
Also, in view of a more scale like version later, I noticed that all Bensen / Wallis types have a nose wheel setup. Would there be any serious disadvantage to go that way? More prone to toppling over on landing maybe?

Max.

[mnowell129]

Mickey, I have ordered the rotor head parts, and I will be starting on a BeGi lookalike pusher soon, based on the sketch you published earlier. Are you making any serious changes lately?
Also, in view of a more scale like version later, I noticed that all Bensen / Wallis types have a nose wheel setup. Would there be any serious disadvantage to go that way? More prone to toppling over on landing maybe?

Max.
I am a day or so away from prototype #2 BEGI. Will put a drawing up as soon as I test fly. Made some changes to the other one that helped the ground handling and got the tail more out of the way of the blades. Also changed the thrust line which improved the takeoffs.
It seems many of the bensen/wallis types have a tail and a nose wheel. I went to Bensen days this year and watched the full sized guys. They rock back on the tail wheel for takeoff after a short taxi on the nose wheel. On landing they touch the mains nose high, then lower to the nose wheel. THe nose wheel is used for taxi.
I tried a nose wheel early on and learned that the models must have a much higher rotor angle than the full size so keeping the nose wheel on the ground is a challenge, thus you had to have a tail wheel anyway. This is aggrevated by the fact that the propeller is much larger diameter on the model relative to the aircraft compared to the full size, so the gear has to be much longer to clear the prop. This makes the trike gear model very "tippy". The additional benefit to nose wheel steering in a full sized is also lost on a model. I'm certain you could put a nose wheel on and use it for taxi, but i'd make sure that I tail wheel (even if disguised) also.

mickey

[max z]

Mickey, thanks for the reply. It is all pretty academic anyway, since I'll be flying mostly off our grass club field, and unless it has been mown shortly before, hand starts are most likely in order. No hard surfaced area safe for flying nearby, and flying in the street would be frowned upon here, especially with my reflexes :eek:

Max.

[bgriggs]

Are these autogyros using collective pitch or fixed pitch? Is collective needed?


Bill

[mnowell129]

Are these autogyros using collective pitch or fixed pitch? Is collective needed?


Bill
All the published ones have been fixed pitch. I've done a collective one and although it helps the takeoff a small amount it's not worth the additional complexity. If at some time I experiement with a pre-spin mechanism then the collective experiment may come back.
mickey

[bgriggs]

All the published ones have been fixed pitch. I've done a collective one and although it helps the takeoff a small amount it's not worth the additional complexity. If at some time I experiement with a pre-spin mechanism then the collective experiment may come back.
mickey

Is there a kit avaible for the G3PO? Cost?

[mnowell129]

Is there a kit avaible for the G3PO? Cost?
Yes. send me an email at mnowell129@earthlink.net for details.
mickey

[Michael R.]

GWS started this "Little Nellie!" design to be RC about 4 years ago. ;)

But this project not being finished. Shall we carry on? :confused:

Mr. Lin, please finish the project.

Michael Ramsey

[mnowell129]

Mr. Lin, please finish the project.

Michael Ramsey
I don't think the gyrocopter market is big enough for GWS....(yet)
mickey