New tandem tractor design and build

Jean Claude

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if you are going to have to be adjusting cyclic in any matter, why have all the drag of a twisted HS and unwanted counter torque after loss of power, when by just tilting the rotor disk to the side to counteract the engine torque offers the most manically simplest, lightest and stable solution and no need to hold hand pressure until you have a power loss?
I just want to clarify a few points in your post:
If the twist of the propeller flow is rectified par le HS, then the rotational kinetic energy is recovered, as Chuck said in post #104 . This means that the drag of the horizontal tail is reduced instead of being increased. Here's how:

 
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DennisFetters

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I just want to clarify a few points in your post:
If the twist of the propeller flow is rectified par le HS, then the rotational kinetic energy is recovered, as Chuck said in post #104 . This means that the drag of the horizontal tail is reduced instead of being increased. Here's how:



I assume you deleted the first post I answered;

I just want to clarify a few points in your post:
Counter the engine torque requires no pressure on the stick. The rotor thrust is still on the roll pivot, even when the head is tilted to the side. It requires just a position of the stick, without any pressure.


If the twist of the propeller flow is rectified par le HS, then the rotational kinetic energy is recovered. This means that the drag of the horizontal tail is reduced instead of being increased. Here's how:

To hold the stick in position requires pressure, or you would not need to manually hold the stick to the side, or hold the stick to correct when loosing engine torque. Admittedly, it is a low pressure, but the annoyance of having to hold it to counteract is the main point I'm making.

For the HL to counteract torque in Michael's application, it must produce lift on opposite sides of the opposite ends and equal to the torque. If not, then it's not counteracting torque. My point is that lift creates drag.

As for your re-post, I do not think your drawing represents what we are talking about here. You are talking about a tall-tail type system or HS close to the prop. We are talking about a twisted HS, or one with adjustable tabs that will produce lift in opposite directions to counteract the torque. In my opinion your Tall-Tail solution would be too far away and the propwash would have become too straight to have the same effect. But, it is all just my opinion since I have not don it.
 

Jean Claude

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I assume you deleted the first post I answered;

To hold the stick in position requires pressure, or you would not need to manually hold the stick to the side, or hold the stick to correct when loosing engine torque. Admittedly, it is a low pressure, but the annoyance of having to hold it to counteract is the main point I'm making.

Dennis, I deleted because I was not sure I understand your post about the stick. But my post was correct. It should not be confused position of the stick and pressure on the stick, except transiently.
Fn produces no torque relatively the roll pivot. So to hold the stick on the side needs no pressure. The only continuous pressure needed is due to the forward speed (b1 angle). It is not due to the engine torque.



For the HL to counteract torque in Michael's application, it must produce lift on opposite sides of the opposite ends and equal to the torque. If not, then it's not counteracting torque. My point is that lift creates drag.
My below sketch is for asymetrical tail, centered in the slipstream. More far behind the propeller, the flow untwists not itself . It is even more accelerated, both in speed and in rotation. The lifts on the opposed sides reduces the drag.

 
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DennisFetters

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Joe, I appreciate the good discussion.

You are correct it the fact that if you accepted to fly at a tilt, you would not need to hold the stick. If you have adjusted the proper rotor disk tilt to compensate for engine torque, then as well your stick is flying in the neutral position and should need no correcting... until you reduce engine torque.

My point it that most pilots, including myself, will not accept flying at a tilt, and will correct after power reduction, and therefor hold the stick into the position that corrects the tilt.

It is my belief that if you had a twisted HS, the airframe torque would change with airspeed, and you would have no neutral stick position throughout a larger parameter of the flight.

True, that due to Bernoulli's principle the propwash cone of airflow will taper inward becoming smaller in diameter and as such accelerates in speed, but I disagree that it increases in rotation after doing so since their will be a fuselage in the middle of the stream and between the engine and the HS.

In Michael's case as we are discussing, we are not just dealing with propwash, but we are dealing with variable airspeeds influencing the desired effect on a twisted HS to solely counteract engine torque. I have flown tractor gyroplanes, not enough to be any kind of an expert, but enough to have a feel for their vulnerabilities.

Theories are one thing, but reality is quit another. Whenever an airfoil creates lift, it create drag, that is a fact of nature. I understand how you are saying that by untwisting the propwash should neutralize the drag, as I don't fully agree, but my point has been that there is more going on with the added airspeed effecting the twisted HS that is not being accounted for.

As a real-life example, any time we are flying an airplane, and add aileron control, the airplane will loose airspeed due to the increased drag. The same thing would happen on a twisted HS.
 
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Jean Claude

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if you accepted to fly at a tilt, you would not need to hold the stick.
My point it that most pilots, including myself, will not accept flying at a tilt.
Without untwisting the propeller flow, you are obliged to accept the tilt changing of the airframe when the engine torque changing. Whatever the position where stands rotor head relative to the mast when you fly right, this reclame no pressure on the side, from full throttle to idle.


It is my belief that if you had a twisted HS, the airframe torque would change with airspeed, and you would have no neutral stick position throughout a larger parameter of the flight.
Of course, it also is my belief! But the engine torque is very variable depending on the flight case, while the forward speed is usually in a narrow range: For example
Optimal climb: 100% of torque and 80% of speed level
Level: 75% of torque and 100% of speed level
Approach: 5% of torque and 80% of speed level

True, that due to Bernoulli's principle the propwash cone of airflow will taper inward becoming smaller in diameter and as such accelerates in speed, but I disagree that it increases in rotation after doing so since their will be a fuselage in the middle of the stream and between the engine and the HS.
In the course of propwash travel from engine to the tail, his radius also changes due the section fuselage, while the angular momentum no changes. Therefore, the angular velocity still increases near the tail, where fuselage section is tapered.

Whenever an airfoil creates lift, it create drag, that is a fact of nature.
True. But you just need to understand that the induced drag is the projection of the pressure resultant on the direction of the velocity of the air. Here the twisted flow by propeller allows two references: general or local. To choose the "forward speed" reference" gives an very different induced drag.

 
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C. Beaty

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Recovery of energy from “twisted” flow is no different than a sailboat sailing into the wind or autorotation.
 

ILikeJetsToo

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Great discussion guys. I've been a bit torn on the best torque compensation method, so I really appreciate reading your discussion on this. Thanks for all the constructive comments.

Michael
 

ILikeJetsToo

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I finally finished vacuum bagging all the Divinycell H45 foam and carbon fiber inner surface plies to the inside of the fuselage. It took longer than I had planned, but I think it turned out really nice. Now the fuselage shell is complete with cored areas from the tail all the way to the firewall. The cored composite sandwich is just for shell buckling stabilization, so core is only needed in the unsupported surface areas. I left solid laminate areas where seats, ribs, bullheads, longerons, and such will be bonded to the inner surface later.

Michael
 

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birdy

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This thread deviation is a prime example of why noone should be banned.
Its probably obvious to most that i dont hold much respect from Dennis, and its mutual, but coz he keeps maken little errors here n there, blokes like CB and JC persist and we all benifit by pickn up useful info from sum very sharp minds.

Nun of this info is relivant to me grown cows but its helpn me gain a better understanding of how sh1t works, so keep it up everyone. :)
Even you Dennis. ;)
 

Xavier AVERSO

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C'est un plaisir de prendre connaissance des sujets de ce forum très instructif mais ne parlant pas Anglais j'ai souvent des incompréhensions avec la traduction de google surtout avec les textes de Birdy, je profite d'ètre en ligne pour saluer Jean Claude avec qui nous avons fait un vol ensemble et aussi Dennis Fetter que j'ai rencontré en Italie a l'occasion d'une petite reunion autogires ou nous avons échangé nos autogires il a volé sur mon Guépard et j'ai volé sur un Air Command c'etait dans les années 80 et j'ai le souvenir d'un très bon pilote.

It is a pleasure to learn about the topics highly informative forum but do not speak English I often have misunderstandings with the translation of the texts google especially with Birdy , I take to be online to greet with Jean Claude that we made a whole flight and also Dennis Fetter I met in Italy during a small meeting or gyroplanes we exchanged gyroplanes he stole my Cheetah and I flew on Air Command c ' was in the 80s and
 

C. Beaty

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You are not alone, Xavier. Birdy confuses some fluent English speakers in addition to Google.

Birdy speaks “strine”, a word that Google may not recognize.
 
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DennisFetters

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This thread deviation is a prime example of why noone should be banned.
Its probably obvious to most that i dont hold much respect from Dennis, and its mutual, but coz he keeps maken little errors here n there, blokes like CB and JC persist and we all benifit by pickn up useful info from sum very sharp minds.

Nun of this info is relivant to me grown cows but its helpn me gain a better understanding of how sh1t works, so keep it up everyone. :)
Even you Dennis. ;)

Why must you insist of cluttering some guys thread up with your personal insults towards people? I'm sure out in the back-land chasing cows all day takes away the time you could have spend studying, but if indeed it's helping you to read about it here, please read, learn and ask questions, but show respect to others and keep your comments and insults out of a good build thread.
 

birdy

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Insults?
Cluttering threads?

Hardn up Dennis.
You know sum, but like the rest of us, not all.
 

DennisFetters

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Insults?
Cluttering threads?

Hardn up Dennis.
You know sum, but like the rest of us, not all.

If that is your problem, then please, let me put your fear to rest and you can get on with your life without feeling the need to insult me further.

Mr. Bird, as I have said in many many posts, I don't know it all. I know a lot due to my 35 plus years flying, designing and manufacturing over 1700 rotorcraft that has flown worldwide. But, by all means I do not know it all nor will I ever know it all and in fact, I try and learn something new every day.

Now, will that give you an ego fix so that in the future you can act like someone we would let into our home? This forum is like our home and we expect people to act well, to be blunt. Not just you, but others that have acted like you as well, so clean your feet before coming in, please.

Michael, I'm so sorry these guys are dragging their bad manners and need to boost their egos into your great build thread. They are my little gremlins that follow me thread to thread and cause trouble that we all unfortunately end up having to deal with and read around.
 
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ILikeJetsToo

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Stay classy

Stay classy

So, I really value the technical input and technical comments (from everyone), and I would appreciate it if we kept things positive, constructive, and on the topics of safety, stability, performance, design, construction, aesthetics, materials, structures, systems, etc....

Like I put in my first post:
Please read the following and comment with constructive critique and technical commentary with the intent of constructive design improvement.

I’ve debated for a while about posting project info on forums. In the past, I have completed large projects (aircraft and other) completely in the privacy of my personal shop, and I have also shared all the details of other large projects openly on forums. I have had mixed feelings about the process both ways. One of the main reasons for deciding to post here now is for everyone to learn and discuss for the betterment of the experimental aircraft community.

If you guys would like me to continue posting about this project, let me know. I would like to make the best gyro I can, so I came here to share information, but if all of this is is old news to you guys, I can just sign out here….

Michael
 

Vance

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An inspiration!

An inspiration!

I find you and your project an inspiration Michael and hope you continue to post updates and questions.

I find the opinions expressed interesting.
 

birdy

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Ditto Michael, sorry for my crap.
Threads like this are gold, so ill button it. ;)
 

ILikeJetsToo

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I had a good weekend working on the gyro. My wife and I hot wire rough cut a block of foam for the engine boot cowling tool, and I worked with my friend Roger to CNC cut the tool from the foam block. The shape turned out great. I spent some time body working the tool surface. It's very smooth and shiny now.

I just started cutting carbon fiber cloth for it and layout out where the ply overlaps will be on the tool. I plan to make the cowling a single composite shell and then cut it in half later when I mount it to the firewall.

I'm applying wax mold release to the form now. I'm always afraid of getting the part stuck to the tool.

Michael
 

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DennisFetters

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I'm applying wax mold release to the form now. I'm always afraid of getting the part stuck to the tool.

Michael

Have you tried the Frekote mold release agents? I only use those now, and have never stuck a part of mold.

http://www.henkel-adhesives.com/industrial/brands-5497.htm?nodeid=8797571973262

Also, have you ever tried Duratec easy sanding primer for plugs?

http://www.adhesivetechnologies.co.nz/duratec.html

It sprays or brushes onto the foam or wood and hardens fast, ready to sand within an hour. Make a hard surface on the foam and pull a mold right off. Fastest way to make a plug I ever found. I even machine a temp mold out of stacks of high density practical board and spray with Duratec and sand it, then using FreKote, and can pull 50 parts at 50F.

They also have in-mold primers for low or high temp.
 
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JAL

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I had a good weekend working on the gyro. My wife and I hot wire rough cut a block of foam for the engine boot cowling tool, and I worked with my friend Roger to CNC cut the tool from the foam block. The shape turned out great. I spent some time body working the tool surface. It's very smooth and shiny now.

I just started cutting carbon fiber cloth for it and layout out where the ply overlaps will be on the tool. I plan to make the cowling a single composite shell and then cut it in half later when I mount it to the firewall.

I'm applying wax mold release to the form now. I'm always afraid of getting the part stuck to the tool.

Michael

So what is the process now? When you say you are making a tool, does that mean you press the tool into the CF or do lay up the CF around the tool?
 
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