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Electric Stunt => New electronic technology => Topic started by: Kim Doherty on August 22, 2013, 02:48:13 PM

Title: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 22, 2013, 02:48:13 PM
Here are the details of the Fly-By-Wire bell crank used in my 2012 W/C's model.

The basic structure is our standard take apart spar assembly and bell crank modified to accommodate a magnet holder and stationary hall effect sensor.

The Pic's:

All the component parts.
Note the object of the assembly is to rotate a set of magnets about a central axel inside which is a stationary hall effect sensor.

Bearing caps installed on main spar.

Bell crank with magnet holder assembled to main shaft.

Fully assembled bell crank

Assembly with hall effect sensor. (sensor is just the tip of the wire)

Sensor installed.

Bell crank installed in wing center section.

Wing flap servo mount (note the leadout!)

Yes Virginia, there really was a fly-by-wire model at the W/C's

_____________________________________________________

The electronics measure the angular deviation of the sensor from the rotational midpoint of the magnetic field and convert that to a standard servo signal to move the control surface.


Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: Mark Mitchell on August 22, 2013, 04:33:48 PM
Fascinating Kim.  How about some particulars on the servo installations.
Title: Re: Fly-by-wire bell crank assembly
Post by: RC Storick on August 22, 2013, 06:56:32 PM
Kim it is interesting but what is the reason for this system?
Title: Re: Fly-by-wire bell crank assembly
Post by: MarcusCordeiro on August 22, 2013, 07:27:05 PM
Crazy!!
So, I believe it would be possible to program the throw, like Igor's system, but one could experimente with diferente combinations just by pushing buttons, like you are setting your eletric motor, you will set the controls...
Is it legal?

Please, post more info... Did i guess right??

Marcus
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 22, 2013, 07:39:53 PM
Mark,

I added a picture of the wing flap servo mount. I never took a picture of the elevator servo. (I was in a bit of a hurry!!)

Robert,

This is the "Fly-By-Wire" system that was so pointedly talked about a couple of years ago. The bell crank is not connected to any pushrods, it simply moves without load generating a signal that is translated into a servo movement and an associated control surface movement. There is no "Netzeband Wall" with this system. The feeling on the handle is not so different than a standard control system. The granularity of the system is very fine and the servos are as fast as you can move so there is no lag. All control surfaces have endpoint control, expo, mixing etc.

Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: Randy Powell on August 22, 2013, 07:55:14 PM
"The more complicated you make the plumbing, the easier it is to stop up the drain".

Montgomery Scott.
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 22, 2013, 08:00:49 PM
Crazy!!
So, I believe it would be possible to program the throw, like Igor's system, but one could experimente with diferente combinations just by pushing buttons, like you are setting your electric motor, you will set the controls...
Is it legal?

Please, post more info... Did i guess right??

Marcus

Hi Marcus,

Yes it is completely programmable. Yes it is legal. It passed technical inspection at the 2012 World Champs in Bulgaria.
We have a programming card and can change any parameter as easily as you could with an R/C transmitter. We are not doing anything that could not be done by changing mechanical connections or linking surfaces to a mechanical  mixer. There is quite a lot written about this in other posts on this forum.

Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: Jason Greer on August 22, 2013, 08:06:15 PM
Very awesome Kim!  Thanks for showing the details. Im sure the feel is much different with no feedback from the flight loads on the control surfaces?

Jason
Title: Re: Fly-by-wire bell crank assembly
Post by: Douglas Ames on August 22, 2013, 10:03:25 PM
There's some Scale guys doing this with pots & servos.
As long as the bellcrank is mechanically linked to the leadouts and controls the elevator via the handle, it's legal.
Title: Re: Fly-by-wire bell crank assembly
Post by: Allan Perret on August 23, 2013, 07:09:55 AM
What does this system weight compared to a standard pushrod / mechanical system ?
Title: Re: Fly-by-wire bell crank assembly
Post by: jim gilmore on August 23, 2013, 07:54:58 AM
Am I correct that if you totally lose the battery power you lose control and have just a plane on a string with no more control than a teather model ??
Title: Re: Fly-by-wire bell crank assembly
Post by: Tim Wescott on August 23, 2013, 08:31:05 AM
There's some Scale guys doing this with pots & servos.
As long as the bellcrank is mechanically linked to the leadouts and controls the elevator via the handle, it's legal.

For FAI, apparently, you don't even need that.

For that matter, I just looked at the AMA rule book, and the rule (rule 2 in CL General) appears to allow other connections than mechanical.  It may be interpreted that way, but it does not call out any difference in the control of the elevator and, say, the pilot waving:

Movement of control surfaces, and any other of the model’s operational features, may be accomplished by mechanical means, by electrical impulses transmitted through the line(s), or by any other control system that does not interfere with the control of any other model or present a safety hazard to competitors or spectators.

If there's some further rule that says that you do, indeed, need mechanical control from wires to elevator, then I missed it -- but I'd love it if it were there.

So if you want, you can be the first pilot in the US to get lynched at a control line meet while protesting "but it's legal!"
Title: Re: Fly-by-wire bell crank assembly
Post by: RC Storick on August 23, 2013, 08:33:57 AM
I guess this pretty much trumps a carbon fiber push rod.


MM

Except for weight.
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 23, 2013, 10:57:47 AM
Except for weight.

Except that the whole model including battery, servos and electronics only weighed 64 ounces.

I know, a real lead sled.   :)

Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: Jason Greer on August 23, 2013, 11:42:15 AM
Which servos are you using?  I assume you have one per flap and one for the elevator?
Title: Re: Fly-by-wire bell crank assembly
Post by: Doug Moon on August 23, 2013, 03:02:12 PM
Kim,

Have you thought about working to incorporate a heading lock gyro?  I use the AR7200 Beastx in my Heli and in the heavy winds it will hold the yaw and pitch axis during hover. The body maybe hanging way off to the left or right but it will just sit there.  Of course I have to stay on it as the winds are always pushing it around.  I have to keep it in one spot.  Only once an input in given will it let up and move to that new input and hold there.  It's quite an insane little piece of equipment. It's lightening fast as well.  I am thinking you could use small trim tabs on either end of the wing and it could constantly keep the plane from rolling.  Then you could have a very small moveable portion of the rudder than would constantly be working to keep the yaw angle at a set rate.  I am certain it could be done seeing what it can do on the heli.  I just wouldn't have a clue where to start with programming it.....

Your bell crank input would go into the BeastX receiver and it mixes the output to the flap and elevator servos.  While the gyro works on the axis at all times.  Is it legal?  Who knows? But it sure would be cool!

On another note there are some pretty beefy brushless metal geared servos out there you could use on your flaps and elevators and the weight gain wouldnt hurt too bad and the stripped gear would not happen again.  I mean I was less than 2 points out this year with my 68 oz plane.
Title: Re: Fly-by-wire bell crank assembly
Post by: Doug Moon on August 23, 2013, 03:35:10 PM
Actually the flap servos would go through the beastx and it would mix the output to control the roll. Just have to run one of them reversed so they go the same direction when BC input is given. But they would also always be acting opposite to control roll!!  I have a friend who is pretty good with it I Amy have to make a call and talk some....  Oh it would be so cool!!
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 23, 2013, 07:33:44 PM
Kim,

Have you thought about working to incorporate a heading lock gyro?  I use the AR7200 Beastx in my Heli and in the heavy winds it will hold the yaw and pitch axis during hover. The body maybe hanging way off to the left or right but it will just sit there.  Of course I have to stay on it as the winds are always pushing it around.  I have to keep it in one spot.  Only once an input in given will it let up and move to that new input and hold there.  It's quite an insane little piece of equipment. It's lightening fast as well.  I am thinking you could use small trim tabs on either end of the wing and it could constantly keep the plane from rolling.  Then you could have a very small moveable portion of the rudder than would constantly be working to keep the yaw angle at a set rate.  I am certain it could be done seeing what it can do on the heli.  I just wouldn't have a clue where to start with programming it.....

Your bell crank input would go into the BeastX receiver and it mixes the output to the flap and elevator servos.  While the gyro works on the axis at all times.  Is it legal?  Who knows? But it sure would be cool!

On another note there are some pretty beefy brushless metal geared servos out there you could use on your flaps and elevators and the weight gain wouldnt hurt too bad and the stripped gear would not happen again.  I mean I was less than 2 points out this year with my 68 oz plane.

Doug,

Congratulations on a great performance at the Nats.

Both Pat and I fly Helis and we have talked about this. There is still so much to learn and so little time or money to do it. I believe it would be legal as you set it and can not change it during flight. I am definitely going to try to incorporate the rudder at some point.  We used composite gears to save weight. (Dumb!!) Metal gears on the next model and a larger servo for the elevator just in case.

Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: Dennis Adamisin on August 23, 2013, 08:27:10 PM
Have been looking forward to hearing more about this - CONGRATS Kim & Pat on a great accomplishment.
Title: Re: Fly-by-wire bell crank assembly
Post by: Mark Mitchell on August 23, 2013, 08:52:55 PM
"Movement of control surfaces, and any other of the model’s operational features, may be accomplished by mechanical means, by electrical impulses transmitted through the line(s), or by any other control system that does not interfere with the control of any other model or present a safety hazard to competitors or spectators."

That language does not really rule out very much at all.  It doesn't even specify any sort of actual physical line being connected to the aircraft.  I'd be willing to bet though that the first time anyone showed up at a contest with a completely RC controlled plane, even if attached to a tether, the rules committee would convene in a right panic to plug the "loopholes".
Title: Re: Fly-by-wire bell crank assembly
Post by: BillLee on August 23, 2013, 09:14:22 PM
Mark, the CL-General rules can be found at http://www.modelaircraft.org/files/2013-2014CLGeneral-1.pdf (http://www.modelaircraft.org/files/2013-2014CLGeneral-1.pdf). Pertinent to your comment is this:


2. General. A Control Line model is flown on one or more' steel or GSUMP, commonly referred to as
Spectra or Dyneema, lines' steel wire line(s) or metal line(s) of equivalent strength, attached to the model in
a manner providing aerodynamic control of the model’s elevation through manipulation of the control
surfaces during flight. “Lines” are that portion of the control system between a connection at the aircraft
and a connection at the control handle consisting of steel wires or metal of equivalent strength. Note that
....

The rules then go on to say

... Manipulation of control surfaces, and
any other of the model’s operational features, may be accomplished by mechanical means, by electrical
impulses transmitted through the line(s), or by any other control system that does not interfere with the
control of any other model or present a safety hazard to competitors or spectators. The use of radio control
to accomplish any control functions on Control Line models is specifically prohibited except as follows.
The use of 2.4 GHz (utilizing spread spectrum, 47 CFR Part 15) radio control to accomplish functions other
than providing aerodynamic control of the model’s elevation
on Control Line models is allowed, but only
to the extent and in the manner specifically allowed by the rules of the individual event. All control
functions must be under the direct control of the pilot and only the pilot.


(Colors and bolding mine for emphasis.)

I don't see where there is any real question about what can and cannot be done.
Title: Re: Fly-by-wire bell crank assembly
Post by: MikeCoulombe on August 23, 2013, 10:26:05 PM
Kim
I agree with Dennis, I have been waiting for more of your research into this innovative control system.
Question, when looking at the servo are you looking at the speed or the torque, I agree that a metal gear servo far surpasses the nylon for durability.
These from HK are super fast.05 sec - 60deg, but may be a little light in the torque only 1.4kg.
http://www.hobbyking.com/hobbyking/store/__23467__TGY_212DMH_Metal_gear_Coreless_Digital_Servo_w_Heat_Sink_1_4kg_05sec_16g.html
But they are also light 16g.
Where as this one is much stronger at 3.9kg, but also slower at .13sec - 60deg. Again also 16g.
http://www.hobbyking.com/hobbyking/store/__23459__TGY_210DMH_Metal_gear_Coreless_Digital_Servo_w_Heat_Sink_3_9kg_13sec_16g.html
Any how Kim I am happy that you are continuing your research. And looking forward to updates.
Mike
Title: Re: Fly-by-wire bell crank assembly
Post by: Doug Moon on August 23, 2013, 10:43:35 PM
From what I am reading it would seem the flybywire would be legal in AMA as well.  He is manipulating the control system with the standard lines connected to a mechanical device, Bell Crank, then it sends the signal for deflection to various places within the model.  There is no RC input here.  The input for deflection of the surfaces is still mechanical.
Title: Re: Fly-by-wire bell crank assembly
Post by: Howard Rush on August 24, 2013, 12:25:59 AM
I think this is a very bad idea.  Stunt will become an autopilot contest. 
Title: Re: Fly-by-wire bell crank assembly
Post by: Bob Hunt on August 24, 2013, 05:24:32 AM
Seems to me that there is a lot of valley between the peak where Kim is right now and the peak at which stunt will turn into an auto-piloted event. I probably won't use this system, but I have great respect for, and highly praise Kim and his team for developing this system to its current state (no pun intended...). I always like to see innovation, and this certainly qualifies!

If, in the future, this system in any way violates the intent of the rules of CL Stunt, then the powers that be can step in and make more stringent rules. For now, let's see just how creative Kim can be within the rules.

Good show, Kim!

Bob Hunt
Title: Re: Fly-by-wire bell crank assembly
Post by: Igor Burger on August 24, 2013, 08:45:46 AM
I see it is here again. Kim will probably write again that I am stopping world from spinning, but my meaning about it is, that it is not good idea. One thing is playing with such stuff, it is ok, I also did many tests also with gyros etc some years ago, may be someone will remember my pictures with servos attached on fuselage, but pushing that stuff to contests is in my eyes not good idea. Yes replacing pushrods with wire does not violate anything, but it opens doors to several unwanted things. In rules working group we analyzed it some year(s) ago, Doug got it immediatelly, it is very easy to connect stabilizing gyros. It is question of minutes and noone can ever check it, because electronic is blat box for outside spectator. Then we can incorporate altitude stabilization from quadcopters. It is also existing and available solution. We can continue this way until we come to battle of programmers or bank accounts. If you do not believe it is doable, you can see several quadcopters flying paralel the same aerobatic pattern on youtube. There are several such videos.

I cannot say that I am not comfortable in such contest, I will certainly enjoy it, but I do not thing it should be done in event dedicated to competition of human abilities. So my meaning is, that "primary function" as defined in FAI F2B rules should stay mechanical.

And I also affraid of safety risks of such solution. But we are here in electric section, so I will not open it.
Title: Re: Fly-by-wire bell crank assembly
Post by: john e. holliday on August 24, 2013, 09:55:31 AM
I hope Kim stays with it.   The videos I have seen of the quad copters flying were indoors.   No outside breezes or turbulent air.   One exception was a video in which the gentleman is using GPS to help control his machine. 
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 24, 2013, 04:56:20 PM
I see it is here again. Kim will probably write again that I am stopping world from spinning, but my meaning about it is, that it is not good idea. One thing is playing with such stuff, it is ok, I also did many tests also with gyros etc some years ago, may be someone will remember my pictures with servos attached on fuselage, but pushing that stuff to contests is in my eyes not good idea. Yes replacing pushrods with wire does not violate anything, but it opens doors to several unwanted things. In rules working group we analyzed it some year(s) ago, Doug got it immediatelly, it is very easy to connect stabilizing gyros. It is question of minutes and noone can ever check it, because electronic is blat box for outside spectator. Then we can incorporate altitude stabilization from quadcopters. It is also existing and available solution. We can continue this way until we come to battle of programmers or bank accounts. If you do not believe it is doable, you can see several quadcopters flying paralel the same aerobatic pattern on youtube. There are several such videos.

I cannot say that I am not comfortable in such contest, I will certainly enjoy it, but I do not thing it should be done in event dedicated to competition of human abilities. So my meaning is, that "primary function" as defined in FAI F2B rules should stay mechanical.

And I also affraid of safety risks of such solution. But we are here in electric section, so I will not open it.

Hi Igor,

We have already had our words over this issue. I told you at the W/C's that I would rather be friends and I still believe that is a better path. You have however raised some interesting points and I would appreciate your views.  Since the first electric stunters in 2006 this has been a "battle" of programmers. You are a programmer, Pat is a programmer, I am a programmer, The people at Schulze and Castle are programmers. Without good programming we would not have proper electric motor runs. As to a battle of the cheque book, FAI aerobatics at the world level long ago crossed that line. A significant number of competitors at the 2012 W/C's flew Yatsenko models at approx: $4,000.00 each. I wish I could afford one. As a member of both the FAI FAI F2 Subcommittee and the FAI F2B Workgroup which you mention I am aware that the result of the discussion was that what I was doing with respect to Fly-By-Wire control was judged to be completely within the rules. I am sure you recognize that I could not have passed technical inspection if my model was not in compliance. I had to answer many questions.

In the paragraph above you said:

"I cannot say that I am not comfortable in such contest, I will certainly enjoy it, but I do not thing it should be done in event dedicated to competition of human abilities. So my meaning is, that "primary function" as defined in FAI F2B rules should stay mechanical."

Do you truly mean this? If you do mean this we need to revert to the most primitive motor/engine control systems ( i.e. engine and muffler and electric motor with no governor). I find this just a bit disingenuous as you yourself rely on an active timer with an accelerometer to control your motor. I see nothing there that a simple human being could accomplish without a lot of technology and programming.

You say that this idea (my idea) is bad. Why is your idea ( active timer with accelerometer) good? You have the same "black box" on your model that I do on mine. (no one can "see" inside your chip)

It sounds a little like the pot calling the kettle "black".

Regardless of your response we will always be friends and I will always have the highest respect for your accomplishments.

Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: jim gilmore on August 24, 2013, 06:56:32 PM
I'm nobody in particular but AI think while it may be an inventive idea.I think it is a bad idea.
I posted before and noone had said when happens in the event of total battery failure ?
Yes thats my one main objection. Granted that on one's lines going slack a model has no control. But you can at least attempt to run and get your lines tight and regain control.
In the event of battery failure what can you do ???
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 24, 2013, 07:39:22 PM
I'm nobody in particular but AI think while it may be an inventive idea.I think it is a bad idea.
I posted before and no one had said when happens in the event of total battery failure ?
Yes that's my one main objection. Granted that on one's lines going slack a model has no control. But you can at least attempt to run and get your lines tight and regain control.
In the event of battery failure what can you do ???

Jim,

I appreciate that you see it as "inventive". It certainly keeps me off the streets.   :)

I do not see much if any difference between an electrical failure and a clogged fuel filter. Depending on when or where they occur the results will not be good. As to running to save a model, at a large contest there are likely to be quite a few people standing in close proximity to the circle. I would not move further than designated pilots circle if something happened. Planes can be replaced.

Kim.
Title: Re: Fly-by-wire bell crank assembly
Post by: john e. holliday on August 24, 2013, 09:09:14 PM
A complete battery failure in level flight, would that be the same as someone flying Class 1 Mouse Racer without a pushrod.   It was done at a NATS and I witnessed it as well as many other people.  Of course the person did not continue as he had no control of the elevator.   Even with the fly by wire and all the programming it still takes a pilot on the handle to make it work.   I too wish I had the finances to get and assemble one of the Yatsenko  Shark and had the knowledge plus ability to program the electronics.   Don't be discouraged Kim.   H^^
Title: Re: Fly-by-wire bell crank assembly
Post by: Igor Burger on August 25, 2013, 12:54:03 AM
We have already had our words over this issue. I told you at the W/C's that I would rather be friends and I still believe that is a better path.

Yes we had, and I am sorry that you again turn it to friendship problem, I have problem with "the thing", not with you. So ... ???



Without good programming we would not have proper electric motor runs.

Exactly and that is reason why we separated "other" functions from "primary" function and all controls of other functions including motor run can be controlled by pilot or also automatically by on board processes. We simply need well working electric power train, because we here in Europe do not have fields where we can fly IC engines anymore. Yes I did lot of in electric power train, reason was not raise battle of programmers, reason was save c/l stunt from death, because we simply cannot continue with IC motors anymore. We lost many fields lately, so we simply needed to do something.


As to a battle of the cheque book, FAI aerobatics at the world level long ago crossed that line. A significant number of competitors at the 2012 W/C's flew Yatsenko models at approx: $4,000.00 each.

Here I cannot agree. Look to top places of last WCh ... I build my model myself, Alex also, Jiri also, ask Paul if he bold his model himself or got it from Yatsenko. Yes, here are many Yatsenko models, but it is also something what can keep stunt alive. They simply cannot build, so they decided to buy it. But it will not fly instead of them, I do not have problem with it. BTW Yatsenko also build his model :- ))))


In the paragraph above you said:

"I cannot say that I am not comfortable in such contest, I will certainly enjoy it, but I do not thing it should be done in event dedicated to competition of human abilities. So my meaning is, that "primary function" as defined in FAI F2B rules should stay mechanical."

Do you truly mean this? If you do mean this we need to revert to the most primitive motor/engine control systems ( i.e. engine and muffler and electric motor with no governor). I find this just a bit disingenuous as you yourself rely on an active timer with an accelerometer to control your motor. I see nothing there that a simple human being could accomplish without a lot of technology and programming.

I will repeat again, even I am sure you know it. I am speaking only and only about primary function, means maneuvering in altitude and attitude as defined by rules. That is what we get score for. You can have my solution, Keith solution, you can have it from CC, Jeti, it will still give you only model which you must control yourself. My complain is to open doors to self controlled models. I can believe author of such device or not. You can hide such function and no one on this world can inspect it. You say that you are programmer, Pat is programmer, so you both must know it. So that is reason for my complains. Not you personally, not your wire or servos, but opened doors. And yes, because I did already such thing, I know what everything can become necessary for good chances in competition.


You say that this idea (my idea) is bad. Why is your idea ( active timer with accelerometer) good? You have the same "black box" on your model that I do on mine. (no one can "see" inside your chip)

Yes exactly I know that I have black box in my model and no one can see what it does. It is not inspectable, so that is reason why I do not want it in path of controls which are after all judged. I hope it is now clear what I mean.


Regardless of your response we will always be friends and I will always have the highest respect for your accomplishments.
Kim, I am, and I never allowed it to be personal. So you not need to call to be friends "again" :- ))))
Title: Re: Fly-by-wire bell crank assembly
Post by: Igor Burger on August 25, 2013, 01:07:34 AM
I do not see much if any difference between an electrical failure and a clogged fuel filter. Depending on when or where they occur the results will not be good. As to running to save a model, at a large contest there are likely to be quite a few people standing in close proximity to the circle. I would not move further than designated pilots circle if something happened. Planes can be replaced.

I did not want to solve safety problems here, but I can say that I do see difference. Having servos on flaps (ailerons) and elevator, you have fully maneuverable model which can fly anywhere. so your model doing crazy movements can easily kill pilot inside the circle (do you still promis not to move more then usual pilot with ill motor?  VD~ ). That is only one of risks. We have our pull test based on hypothesis that our model flies on lines, but it will be different if it flies cross the circle and lines must survive shock on opposite side of circle, so we will probbaly need to redesign our safety rules. I hope we will not end up with fences around our circles, because that is certain death of stunt minimally in our country.

Yes I know that wilde moving of controll surfaces has very low probability, but I can easily imagime servo failure on inner flap of last vingover corner which will roll model inside the circle and elevator will turn it towards the pilot with similar consequences.

Remember, broken pushrod will make model flying straight, means predictable, while failure in FBW system make it crazy flying around.

I hope still friends :- ))))
Title: Re: Fly-by-wire bell crank assembly
Post by: Paul Smith on August 25, 2013, 04:56:45 AM
I think this is a very bad idea.  Stunt will become an autopilot contest. 

Good or bad, you are correct in extrapolating that an off-the-shelf autopilot could be inserted into the system to give perfect 5' level flight except when overcome by the turn knob.
Title: Re: Fly-by-wire bell crank assembly
Post by: Howard Rush on August 25, 2013, 11:23:34 PM
Even with the fly by wire and all the programming it still takes a pilot on the handle to make it work.

Not much of a pilot.  That's Igor's point.
Title: Re: Fly-by-wire bell crank assembly
Post by: Lauri Malila on August 26, 2013, 04:17:13 AM
 About the safety worries; there is maybe million times more RC models flying, many of them much more complicated and quite many operated by morons. And not so many serious accidents. Why is Kim's system suddenly so dangerous? L
Title: Re: Fly-by-wire bell crank assembly
Post by: MarcusCordeiro on August 26, 2013, 05:35:09 AM
Well, once cars had csrburators, then EFI with cable-operated TB, now there's eletronic TBs totally programmable... I guess it's an option, and I like it. Don't see it as a dangerous thing.
But that's me..

Marcus
Title: Re: Fly-by-wire bell crank assembly
Post by: Derek Barry on August 26, 2013, 10:45:49 AM
I agree with Howard and Igor. Cool but no good for stunt competition. If people start to use them I will draft a rules proposal to have them banned.

Derek
Title: Re: Fly-by-wire bell crank assembly
Post by: Steve Fitton on August 26, 2013, 01:57:56 PM
Howard (and I am asking this "for reals"), wouldn't you need a radar altimeter onboard to make it an autopilot event?

Or is the possibility for yaw or roll stability augmentation enough to argue against the fly by wire concept.
Title: Re: Fly-by-wire bell crank assembly
Post by: Doug Moon on August 26, 2013, 10:07:26 PM
I have seen the quad copters doing their thing and it is quite amazing to say the least.  I saw one where the stood a 5' wooden dowel on top if it and it balanced it.  BUT it needed programing from the outside to keep it all going.  Plus it was in a an area where it could send signals to a certain area so it knew where it was at all times and could create an "area of flight" or a map of some sort.  It is crazy cool! In stunt we still have to waive the handle.  The surfaces must be controlled by the handle and if that is happening then what does it matter how the surface is moved only that it is moved with the action of the handle connected directly to the control system.

As far as gyros go for stabilization.  I think it would be killer.  In flight trimming!  BUT you have to be able to adjust the gains on gyros to get the proper response.  I have to adjust mine on my helicopter often.  It would be a constant battle of trim every time you go out a fly to make sure it is was acting properly for the conditions.  What if said conditions change in mid flight and you cant make changes....??  Changing the trim every time you go out...sound familiar?  Yep we chase that around all the time but for the most part once we are close there are very few changes made.  We can overcome changing conditions mid flight because our system on board is at one setting the entire time. We can use our brains and sometimes our brawn to go over the flight trim we have set and still make it look good.  A gyro out of sync will actually make things far worse as this would be an active system putting in too much roll / anti-roll, yaw / anti-yaw corrections.  It could be a huge disaster.  But if you got one to work it would be pretty cool if you ask me! 

As far as programmed stunt.  That would be very difficult to do without on board altimeter and mapping.  It is not a simple, program the servo to turn 90 degrees once the up input is given.  If it were that simple the plane would have start from a perfect 0 degrees AoA and we never fly at the perfect 0.  If you aren't at the perfect 0 and you turn it and it goes 90 and stops the leg wont be straight.  When you make a correction it is in the programmed maneuver waiting for the next input to turn 90 again, now your correction is actually a whole 90 degree turn again and the maneuver is lost. 

Autopilot would be outlawed for sure as you don't have to wave the handle.  You are not actually controlling the surfaces in that case so it is already a non issue.
Title: Re: Fly-by-wire bell crank assembly
Post by: Jason Greer on August 26, 2013, 10:34:31 PM
It would be very nice to have an alternative to a fully mechanical control system. The infinite combinations of flap to elevator ratio mixing and expo/reverse expo combinations through software is very enticing. Adjusting flap and elevator neutral settings would be so much easier! 

Preventing autonomous systems would be tricky, but I would hope some medium could be developed to prevent the all out banning of servo based control systems. 

Thanks,
Jason

PS: Doug are you going to be flying in Dallas this weekend?  We are planning to be there.
Title: Re: Fly-by-wire bell crank assembly
Post by: Jason Greer on August 26, 2013, 11:16:17 PM
How functional could an autopilot system operate if the flaps were not allowed to function as ailerons and the rudder was not allowed to be servo driven? I realize Kim's model has independently actuated flaps.  If the flaps are required to be physically connected to one another to prevent independant movement and the rudder was not tied to a servo, then the potential for the model turning into the circle due to servo malfunction would be greatly reduced.  In this configuration, a servo malfunction would simply cause the model to pitch up or down.

Title: Re: Fly-by-wire bell crank assembly
Post by: Brett Buck on August 26, 2013, 11:57:56 PM
I agree with Howard and Igor. Cool but no good for stunt competition. If people start to use them I will draft a rules proposal to have them banned.

Derek

   Probably should do it BEFORE, if you are going to do it ever. Igor's argument about black boxes is pretty much identical to my and others previous points - you have a black box of unknown function, some signals go in, and some signals come out. And you have no idea what it does.

    What Kim is currently doing looks fine to me, but you must have some way to determine that it is not an autopilot. I suggested that we ought to come up with some better way of determining what the box was doing a few years ago.  But eliminating electronics in the pitch axis certainly solves the problem, as crude as it is.

    Brett
Title: Re: Fly-by-wire bell crank assembly
Post by: Derek Barry on August 27, 2013, 04:47:44 AM
   Probably should do it BEFORE, if you are going to do it ever. Igor's argument about black boxes is pretty much identical to my and others previous points - you have a black box of unknown function, some signals go in, and some signals come out. And you have no idea what it does.

    What Kim is currently doing looks fine to me, but you must have some way to determine that it is not an autopilot. I suggested that we ought to come up with some better way of determining what the box was doing a few years ago.  But eliminating electronics in the pitch axis certainly solves the problem, as crude as it is.

    Brett

Maybe I will...

I am not really concerned about getting beat by a "smart plane", I just think adding servos to stunt is a bad idea and it goes against what I believe stunt to be.

Derek
Title: Re: Fly-by-wire bell crank assembly
Post by: David Hoover on August 27, 2013, 10:52:10 AM
"If it ain't broke don't fix it"  If that had been Jim Walker's attitude we wouldn't even have control line flying as we know it.  I'm sure that there was nothing wrong with free flight flying in his day, it wasn't "broke", but he saw something different.  In all these discussion about keeping the event "like it's always been" it is always forgotten that the pioneers of the event used the best technology that was available to them at the time.  If control line flying were invented today with the availability of today's technology, who knows what our control systems would look like?  They might be quite different from what we're accustomed to.  Is a fly-by-wire system a viable way of controlling a stunt plane or does it have significant advantages over current control systems or is it too finicky, prone to problems or have other flaws that outweigh the theoretical advantages?  We don't know yet.  So we should stop bickering (seems to be controliners second nature) and encourage Kim and others like him to keep trying, keep experimenting, keep struggling and see what comes of it.  They're advancing the state of the art and need to be commended for it.
Title: Re: Fly-by-wire bell crank assembly
Post by: Derek Barry on August 27, 2013, 12:08:26 PM
  If control line flying were invented today with the availability of today's technology, who knows what our control systems would look like?  They might be quite different from what we're accustomed to. 

Yeah, they would cut the leadouts off and call it RC.

The problem is not that people want to try new things and develop new technology, it is when those things push the boundaries of what should and should not be allowed in competition. I do not think that having servos move the control surfaces will give anyone an advantage over anyone else. If anything, not having feedback from the controls could make it more difficult to fly. I just think allowing servos and programmable settings on control surfaces will open up a can of worms that will be very hard to close if it gets out of hand. Kind of like the recent BOM/composite debates. Nobody will be able to tell what is and what is not legal...

Derek
Title: Re: Fly-by-wire bell crank assembly
Post by: Brett Buck on August 27, 2013, 05:54:15 PM
Maybe I will...

I am not really concerned about getting beat by a "smart plane", I just think adding servos to stunt is a bad idea and it goes against what I believe stunt to be.

Derek

  Generally, I agree with you. I think allowing 2.4 GHz control is far more like that than a sensor/servo-based bellcrank, but I can see it either way. Control-line means "control through the lines" so I can argue either way on the bellcrank *IF* there was a way to determine the functionality is limited to merely reflecting the control inputs. Right now, I can't see how to do that, nor could I 15 years or so ago when this first came up, hence the "mechanical connections" proposal in FAI (that didn't get adopted).

   Brett
Title: Re: Fly-by-wire bell crank assembly
Post by: Dennis Moritz on August 27, 2013, 08:15:44 PM
What's the point of handing this hobby over to technicians and programers. I am totally bored by the idea of buying my way into defeating Brett, Paul, Howard, Bob, Kaz, Doug, Derrick and all. Took a while for me to understand the implications of Paul Walker's faux Fox burp. I think it's against the spirit of Control Line Stunt. There is no adequate comparison to what preceded this. Since all tuning before electric was fundamentally mechanical and did not use in any way an on board computer.
Title: Re: Fly-by-wire bell crank assembly
Post by: jim gilmore on August 27, 2013, 08:51:29 PM
All we need is for somebody to find a way to tell the aircraft how to return to level flight and it will them be a contest of manuevers above the 4- 6 Ft level flight zone.
Make a wing over and the ac automatically truns itself to achieve level attitude in the right place.Then yours doing squares and only needing to control 3 out of 4 corners.. Granted this is beyond what the new cotrol is now..but where do new techs stop ??
 
Title: Re: Fly-by-wire bell crank assembly
Post by: Kim Doherty on August 27, 2013, 10:24:00 PM
What's the point of handing this hobby over to technicians and programers. I am totally bored by the idea of buying my way into defeating Brett, Paul, Howard, Bob, Kaz, Doug, Derrick and all. Took a while for me to understand the implications of Paul Walker's faux Fox burp. I think it's against the spirit of Control Line Stunt. There is no adequate comparison to what preceded this. Since all tuning before electric was fundamentally mechanical and did not use in any way an on board computer.

It is not yours or mine or anyone elses to hold on to or to hand over. Your part is that of active observer/participant. Be thankful it was a going concern during your lifetime. As to handing it over to programmers I doubt that you have built as many stick and tissue FF, Rubber, Indoor or C/L as this programmer has in the past 52 years. I also doubt that you actively participate in trying to advance or preserve the essence of this incredible pass time.  If you want to defeat Paul or Bob then you surely know the way to Carnegie Hall. Why don't you go do something productive like going to school to learn ASL so you can teach deaf kids to fly. How about running a build and fly clinic for a thousand or so kids. How about anything other than complaining or gum flapping.

There are no on board processors in Hoops and Sticks, Hula Hoops, Super Balls, Tops, Edsels etc. All gone. As surely gone as control line will be if it remains in its current state. Your concern and that of others rings hollow. No one has cheated. No one intends to. Go ahead and further isolate the good ole USA from the rest of the world. Why let facts interfere with good old fashioned story telling.

Frankly Scarlet there is not enough money to buy a victory over any of the above mentioned competitors even if they gave the technology away. Oh I forgot, you know about the burp.

Kim.   S?P
Title: Re: Fly-by-wire bell crank assembly
Post by: Dennis Moritz on August 27, 2013, 10:55:55 PM
RC does all that you describe Kim. At a more sophisticated level. So what. If I wanted to fly RC, I would fly RC. Keep going in this direction of development and the lines attached to the bird will be without a purpose. Might as well hang them on your neck and turn around and around in a circle. Control Line, Free Fight, building with balsa and tissue and dope doesn't capture the imagination of many young people. Most of us can't work on our cars anymore either. At least not the modern one. Unless we understand the electronics. People don't build anything much these days, work with their hands. Eras pass. In the fifties when I was coming up CL was happening all over the place. Even in NYC. No one coaxed me into the hobby. No one handed it to me. I was drawn to it. In fact, I never met an adult who flew control line until I was an adult myself. Most of us, I bet, were like that. I plan to go on building and flying traditional control line airplanes until my aching back and stiffening arthritic fingers make it impossible. I will continue to compete at my own sorry level of skill because it's fun. Killing off the essence of Control Line flying is no way to save it.

Yeah. Far as I'm concerned Paul Walker did cross a line. The velocity whatever electronic on board computer should not be allowed in competition stunt.
Title: Re: Fly-by-wire bell crank assembly
Post by: Keith Renecle on August 28, 2013, 12:02:59 AM
Here's my 10 cents worth. First up I think that I would particularly like to say a big thank you to Kim for posting all the details of this most interesting and innovative project. Kim and Pat have really put a lot of work into this, so thanks very much for sharing! I have to admit freely that I personally believe that C/L should only use direct mechanical connections to the control surfaces, and I was one of those that pushed for this on the FAI committee. Having said that, I still think that it is a marvellous project that was not just something on a note pad or drawing board, but was tested on the real thing by Kim and Pat. As to any serious advantage over the mechanical stuff, I would say that without feedback to the pilot, it could have a disadvantage. Precise maneuvers require the pilot to feel what the control surfaces are doing, and although this is technically possible, it sure isn't easy.

On the Dennis Moritz statement of Paul Walker crossing the line by using Igor's accelerometer system, it sure sounds like Paul had some HUGE advantage? Look at the top 5 Nats scores. Paul beat Doug by 1 point, and that was put down to the 1 extra point from the finish of the Predator. Igor's system basically tries to replicate the 2/4 break engine system, and does a very good job of it. As Igor pointed out, having such good performance in a quiet power system saves flying fields, especially in Europe. The real advantage is that the e-power systems are more reliable/predictable in changing weather conditions, but as far as functionality goes, the 2/4 break engine system is also a feedback system, especially with a tuned pipe setup. Where's this unfair advantage whereby Paul crossed the line??

As Derek correctly pointed out in a similar debate, the top stunt guys really know and understand their engines well, so they are not really at any disadvantage against a system like Igor's. The real advantage to C/L stunt for the masses of us that are not at "guru" level, is that we can buy a good flying stunt power package a lot easier a lot easier now that we can plug & play and it will work as well as the engines that previously only the guru's could get to work.

Keith R
Title: Re: Fly-by-wire bell crank assembly
Post by: Derek Barry on August 28, 2013, 05:00:57 AM
Here's my 10 cents worth. First up I think that I would particularly like to say a big thank you to Kim for posting all the details of this most interesting and innovative project. Kim and Pat have really put a lot of work into this, so thanks very much for sharing! I have to admit freely that I personally believe that C/L should only use direct mechanical connections to the control surfaces, and I was one of those that pushed for this on the FAI committee. Having said that, I still think that it is a marvellous project that was not just something on a note pad or drawing board, but was tested on the real thing by Kim and Pat. As to any serious advantage over the mechanical stuff, I would say that without feedback to the pilot, it could have a disadvantage. Precise maneuvers require the pilot to feel what the control surfaces are doing, and although this is technically possible, it sure isn't easy.

On the Dennis Moritz statement of Paul Walker crossing the line by using Igor's accelerometer system, it sure sounds like Paul had some HUGE advantage? Look at the top 5 Nats scores. Paul beat Doug by 1 point, and that was put down to the 1 extra point from the finish of the Predator. Igor's system basically tries to replicate the 2/4 break engine system, and does a very good job of it. As Igor pointed out, having such good performance in a quiet power system saves flying fields, especially in Europe. The real advantage is that the e-power systems are more reliable/predictable in changing weather conditions, but as far as functionality goes, the 2/4 break engine system is also a feedback system, especially with a tuned pipe setup. Where's this unfair advantage whereby Paul crossed the line??

As Derek correctly pointed out in a similar debate, the top stunt guys really know and understand their engines well, so they are not really at any disadvantage against a system like Igor's. The real advantage to C/L stunt for the masses of us that are not at "guru" level, is that we can buy a good flying stunt power package a lot easier a lot easier now that we can plug & play and it will work as well as the engines that previously only the guru's could get to work.

Keith R

I agree with you Keith, 100%

Derek
Title: Re: Fly-by-wire bell crank assembly
Post by: Dennis Moritz on August 28, 2013, 06:36:53 AM
I think mechanical adjustments, pipe length, head gaskets, venturi size, prop, fuel and so on, all of those many factors, plus all of the manifold trim adjustments to the airplane itself, are one kind of skill set. Moving to electronic tuning is qualitatively different. It opens the door to the creation of more sophisticated on board controls of the model. I think it accurate to describe these controllers as programmable computers. We are seeing this approach in its infancy. It already is very effective. Looks to me like it will take over and dominate the competition as it develops further. Why couldn't later iterations of this smooth out flight paths, as someone pointed out, allow models to fly at 5', exactly, make a circle a circle, a square an accurate square. Compensate in many ways for poor wiggles of the handle, changing orientations towards a breeze and so on. If this is the case, an excellent pattern flight will be more and more a function of the programmer and the sophistication of the on board electronics, and less and less a function of pilot skill in piloting.  

On board computers on full sized aircraft make it possible for inherently non-aerodynamic shapes to fly. I have flown $30 dollar RC helicopters that have all kinds of stability control, allow me to hover and so forth. Fun. For a little while. But this is different from flying control line.

Kim is an enthusiast, a hobbyist. All to the good. He is committed to widening interest in our hobby. Also to the good. It sounds to me like his heart is in the right place. Paul Walker is totally committed to the Control Line Stunt Hobby. A great competitor over many many years. One who obviously can compete on the highest level without the benefit of on board electronic (computer) enhancements.  But I think his current approach is antithetical to the spirit of this hobby. My apologies to Kim, Paul, and everyone else. My bluntness is honest. I have spent time thinking about these issues. Ever since the first posts describing these controllers happened. More than a year ago I believe. Come to think of it, Howard Rush described these controllers to me at the 2012 NATS. It raised red flags then.
Title: Re: Fly-by-wire bell crank assembly
Post by: Derek Barry on August 28, 2013, 07:34:22 AM
I think mechanical adjustments, pipe length, head gaskets, venturi size, prop, fuel and so on, all of those many factors, plus all of the manifold trim adjustments to the airplane itself, are one kind of skill set. Moving to electronic tuning is qualitatively different. It opens the door to the creation of more sophisticated on board controls of the model. I think it accurate to describe these controllers as programmable computers. We are seeing this approach in its infancy. It already is very effective. Looks to me like it will take over and dominate the competition as it develops further. Why couldn't later iterations of this smooth out flight paths, as someone pointed out, allow models to fly at 5', exactly, make a circle a circle, a square an accurate square. Compensate in many ways for poor wiggles of the handle, changing orientations towards a breeze and so on. If this is the case, an excellent pattern flight will be more and more a function of the programmer and the sophistication of the on board electronics, and less and less a function of pilot skill in piloting.  

On board computers on full sized aircraft make it possible for inherently non-aerodynamic shapes to fly. I have flown $30 dollar RC helicopters that have all kinds of stability control, allow me to hover and so forth. Fun. For a little while. But this is different from flying control line.

Kim is an enthusiast, a hobbyist. All to the good. He is committed to widening interest in our hobby. Also to the good. It sounds to me like his heart is in the right place. Paul Walker is totally committed to the Control Line Stunt Hobby. A great competitor over many many years. One who obviously can compete on the highest level without the benefit of on board electronic (computer) enhancements.  But I think his current approach is antithetical to the spirit of this hobby. My apologies to Kim, Paul, and everyone else. My bluntness is honest. I have spent time thinking about these issues. Ever since the first posts describing these controllers happened. More than a year ago I believe. Come to think of it, Howard Rush described these controllers to me at the 2012 NATS. It raised red flags then.

Those are some very good points Dennis. When I got to the Nats and talked to Paul for the first time he was explaining to me some of the problems he faced getting the "Igor" system to work properly for him. It sounded way more complicated than my stock PA65 setup. Now, once he had it right it seemed to work really well for him, obviously... I can see your point that it may give a person who is not great at running an IC motor a leg up but I didn't feel that his setup, even as sophisticated and it was, had any advantage over my and Doug's PA setups. Essentially he made his electric run like my IC which seems kinda asinine but hey, whatever floats your boat. You are very correct about the stuff that is available right now at any local hobby shop. The stability control systems could be used, if for nothing else, to have in flight trim adjustments. Making it very easy to have a plane that never rolls, yaws, or does anything "funny". Basically taking any plane and making it stay in perfect trim at all times no matter what the weather is like. This is a real advantage that should be nipped in the bud right now.  Like you said, the onboard computers can make the most non-aerodynamic planes fly very well. Yes it is cool but it is against the "idea" of control line stunt for competition.  Now as for having fun and trying new things, I applaud Kim for his invention. I am sure that it is interesting to fly, hell maybe they can even come up with a new event for that system. Call it Hybrid stunt...

Derek
Title: Re: Fly-by-wire bell crank assembly
Post by: RC Storick on August 28, 2013, 03:26:26 PM
In 1969 Any Granitilli put a turbine car driven by Parnelli Jones into the Indy race he was 2 laps ahead of everyone until a 4 dollar bearing let loose.The next year Joe Lenard drove a turbine wedge car with not as much success because they put a size limit on the intake. They do it in stock car racing, drag racing and unlimited hydro. The word Unlimited with restrictions is a contradiction. If Kim wants to invest his time and money into this system I see no reason to stop him. Some are missing the fact that there will be no feed back to the handle.

In my opinion more complicated is not always better but what do I know?
Title: Re: Fly-by-wire bell crank assembly
Post by: Gus Urtubey on September 17, 2013, 08:53:29 PM
I am so proud of Pat and Kim for doing this real advance in flight controls. The fact of being able to adjust the flight controls to get a perfect trim even for different weather conditions it is absolutely fantastic. Even if we can do some adjustment with the conventional system, I always felt that you are kind of stuck with your settings.

I can see this is the way it is going to go in the near future, it will be like going from IC to electric power trains.

Keep up the good work guys !!!!!

Title: Re: Fly-by-wire bell crank assembly
Post by: Dennis Toth on September 27, 2013, 09:17:59 AM
Dennis,
I think there is one thing you are missing in your prediction of Robo-Stunt. The rules require control input from the control lines. How the control surfaces are moved can be by any means but the input is from the control lines. Having any type of automatic trimming or movement input of the control surface by anything other than it being directed from the control wires is not allowed.

What Paul and Igor have done with the motor control is to simulate what is already been used for over 50 years. It doesn't give any big advantage over other setups that are working correctly. It still comes down to the person twisting the handle. Paul could be given a Ringmaster with a Fox35 and after about a week would likely be able to beat 90% of the fliers in this event.

Look at some of the contest results, Dan Banjok (sp?) has beaten lots of top east coast fliers with a Fox 35 (even himself, scored better in classic with the Galloping Comedian then he did in expert with the big full blown ship).

I think there has been lots of technology that has come and gone in this event and we survived it all.

Best,           DennisT
Title: Re: Fly-by-wire bell crank assembly
Post by: CircuitFlyer on September 27, 2013, 08:44:20 PM
Kim,

Congratulations on you team trial results!!  http://www.balsabeavers.com/events/2013/2013_09_15_fall_stunt/2013_09_15_fall_stunt_report.pdf 

Are you going to give us a sneek peak at what you have in mind for Poland next Summer?  Or, is it top secret for now?

Paul
Title: Re: Fly-by-wire bell crank assembly
Post by: phil c on March 24, 2014, 06:35:27 PM
The AMA rules are pretty clear- Control Line General para.2-  A Control Line model is flown by one or more line(s)......attached to the model in manner providing aerodynamic control of the model's elevation through manipulation of the control surfaces during flight.

That doesn't seem to allow much wiggle room since the lines muct "provide aerodynamic control".  If the controls are actually powered by servos the lines do not "provide aerodynamic control", the servos do.

The F2B rules ABR 4c 1.3.2 state: 
a) Control Line Circular Flight is flight during which all control is accomplished via physical connection to the pilot through one or more inextensible wires or cables directly connected to the model aircraft.  The control wires or cables must be attached to a hand held device(control handle).  Automatic flight path control and/or automatic maneuvering are not permitted.

b) powertrain control may be accomplished by the pilot via the control wires or cables or by an onboard, self-contained, automatic process.

Whoever interpreted "all control is accomplished via physical connection to the pilot through one or more inextensible wires or cables directly connected to the model aircraft" to mean that control by electronics and servos is a "physical connection" must have had an excellent lawyer.  One ordinarily wouldn't interpret "physical" to mean electronic connection or electric connection.  A switch with metal contacts turning on a light could be interpreted as physical operation, but using an electronic sensor powering a servo is not a physical connection.  The physical connection is between the servo and the control surfaces.  Any electric servo that we would use runs without a physical connection between the electrical paths in the motor and the physical part that turns.  The motor rotor is coupled magnetically, without physically touching.  But then, I'm not a lawyer.

This is not to belittle the electrical engineering involved in designing and building the system.  It is quite an achievement.
Title: Re: Fly-by-wire bell crank assembly
Post by: Tim Wescott on March 24, 2014, 08:50:59 PM
The AMA rules are pretty clear- Control Line General para.2-  A Control Line model is flown by one or more line(s)......attached to the model in manner providing aerodynamic control of the model's elevation through manipulation of the control surfaces during flight.

That doesn't seem to allow much wiggle room since the lines muct "provide aerodynamic control".  If the controls are actually powered by servos the lines do not "provide aerodynamic control", the servos do.

I read that same thing, only I interpret "provide aerodynamic control" as providing the command signal, which can then be directly coupled to the elevator, or not.

The F2B rules ABR 4c 1.3.2 state: 
a) Control Line Circular Flight is flight during which all control is accomplished via physical connection to the pilot through one or more inextensible wires or cables directly connected to the model aircraft.  The control wires or cables must be attached to a hand held device(control handle).  Automatic flight path control and/or automatic maneuvering are not permitted.

b) powertrain control may be accomplished by the pilot via the control wires or cables or by an onboard, self-contained, automatic process.

Whoever interpreted "all control is accomplished via physical connection to the pilot through one or more inextensible wires or cables directly connected to the model aircraft" to mean that control by electronics and servos is a "physical connection" must have had an excellent lawyer.  One ordinarily wouldn't interpret "physical" to mean electronic connection or electric connection.  A switch with metal contacts turning on a light could be interpreted as physical operation, but using an electronic sensor powering a servo is not a physical connection.  The physical connection is between the servo and the control surfaces.  Any electric servo that we would use runs without a physical connection between the electrical paths in the motor and the physical part that turns.  The motor rotor is coupled magnetically, without physically touching.  But then, I'm not a lawyer.

This is not to belittle the electrical engineering involved in designing and building the system.  It is quite an achievement.

Are you saying that the bellcrank is not part of the aircraft?  The rule you quote does not say anything about there being a physical connection inside the aircraft, just that the wires must extend from the pilot to the aircraft.

I don't think this is "excellent lawyering" at all -- I think that the FAI rules pretty clearly allow what Kim is doing, or at least they pretty clearly don't rule them out in any way shape or form.
Title: Re: Fly-by-wire bell crank assembly
Post by: Mike Anderson on March 25, 2014, 11:54:08 AM
The AMA rules are pretty clear- Control Line General para.2-  A Control Line model is flown by one or more line(s)......attached to the model in manner providing aerodynamic control of the model's elevation through manipulation of the control surfaces during flight.

That doesn't seem to allow much wiggle room since the lines muct "provide aerodynamic control".  If the controls are actually powered by servos the lines do not "provide aerodynamic control", the servos do.


Actually, paragraph two reads:

2. General. A Control Line model is flown on one or more' steel or GSUMP, commonly referred to as Spectra or Dyneema, lines' steel wire line(s) or metal line(s) of equivalent strength, attached to the model in a manner providing aerodynamic control of the model’s elevation through manipulation of the control surfaces during flight. Movement of control surfaces, and any other of the model’s operational features, may be accomplished by mechanical means, by electrical impulses transmitted through the line(s), or by any other control system that does not interfere with the control of any other model or present a safety.

 ... or at least it does in the 2013/2014 rulebook.

This would seem to permit control of the elevator by servo's, either controlled by pulses down the lines or by manipulation of a bellcrank that has no mechanical connection to the elevator.

Title: Re: Fly-by-wire bell crank assembly
Post by: Brett Buck on May 17, 2014, 11:49:44 PM
Actually, paragraph two reads:

2. General. A Control Line model is flown on one or more' steel or GSUMP, commonly referred to as Spectra or Dyneema, lines' steel wire line(s) or metal line(s) of equivalent strength, attached to the model in a manner providing aerodynamic control of the model’s elevation through manipulation of the control surfaces during flight. Movement of control surfaces, and any other of the model’s operational features, may be accomplished by mechanical means, by electrical impulses transmitted through the line(s), or by any other control system that does not interfere with the control of any other model or present a safety.

 ... or at least it does in the 2013/2014 rulebook.

This would seem to permit control of the elevator by servo's, either controlled by pulses down the lines or by manipulation of a bellcrank that has no mechanical connection to the elevator.

   I think that this is correct, there is nothing preventing fly-by-wire in the current or proposed rules. I think we hashed this out over on SSW when Kim first showed it to be practical, and nothing has changed about it, rule-wise, since then.

    I was a bit surprised that there wasn't such a proposal this time but Howard was trying to build his airplane.

    Brett
Title: Re: Fly-by-wire bell crank assembly
Post by: Steve Fitton on May 21, 2014, 06:09:01 AM
   I think that this is correct, there is nothing preventing fly-by-wire in the current or proposed rules. I think we hashed this out over on SSW when Kim first showed it to be practical, and nothing has changed about it, rule-wise, since then.

    I was a bit surprised that there wasn't such a proposal this time but Howard was trying to build his airplane.

    Brett

There is no way to define fly by wire control systems succinctly enough for a rule change proposal, don't think that people have not thought of it.  Anti fly by wire proposals make the BOM proposal seem childishly simple in comparison.
Title: Re: Fly-by-wire bell crank assembly
Post by: Brett Buck on May 22, 2014, 12:12:46 AM
There is no way to define fly by wire control systems succinctly enough for a rule change proposal, don't think that people have not thought of it.  Anti fly by wire proposals make the BOM proposal seem childishly simple in comparison.

   2.5 All connections between the lines and the aerodynamic control surfaces shall be completely mechanical.

   Seems simple enough to me, if that's what we want.

    Brett

Title: Re: Fly-by-wire bell crank assembly
Post by: Steve Fitton on May 22, 2014, 07:06:36 AM
  2.5 All connections between the lines and the aerodynamic control surfaces shall be completely mechanical.

   Seems simple enough to me, if that's what we want.

    Brett



Give Wescott five minutes with that....   n~
Title: Re: Fly-by-wire bell crank assembly
Post by: Tim Wescott on May 22, 2014, 10:15:36 AM
Give Wescott five minutes with that....   n~

Hey!

Actually, I think it would be hard to argue against the meaning of that.  If you were worried that someone might argue that electrons flowing through wires are "just mechanical" (No, I won't) then you could probably come up with some verbiage -- but the better thing to do, IMHO, would be to use the rule as Brett wrote it, then change it the next cycle if some smart-ass finds a loophole.
Title: Re: Fly-by-wire bell crank assembly
Post by: Steve Fitton on May 22, 2014, 12:42:46 PM
Maybe it should go in the CLPA section instead of General?

I still there is a big issue somewhere in the notion of a proposal, something that stopped cold previous efforts with some people I know.  I will ask them and see if they remember the issue.
Title: Re: Fly-by-wire bell crank assembly
Post by: Sean McEntee on May 23, 2014, 05:29:51 PM
My concern is the aforementioned, always possible  event of system failure. Anything with moving pieces can break, and this type of system failing would lead to putting Issac Newton in the pilot seat for a few seconds at most.

Have you considered adding a small pushrod going out to at least the elevator?  Doesn't have to be as beefy as a conventional pushrod system--just enough to keep control in the event of system failure.  

#safety

   A pushrod would also eliminate allot of this discussion. You would still have mechanical control of the surfaces, and the servos would simply be aiding the deflection of the surfaces--maybe to reduce load (not that there is allot anyway). Just an idea.
Title: Re: Fly-by-wire bell crank assembly
Post by: Brett Buck on May 29, 2014, 12:34:39 AM
My concern is the aforementioned, always possible  event of system failure. Anything with moving pieces can break, and this type of system failing would lead to putting Issac Newton in the pilot seat for a few seconds at most.

Have you considered adding a small pushrod going out to at least the elevator?  Doesn't have to be as beefy as a conventional pushrod system--just enough to keep control in the event of system failure.  

#safety

   A pushrod would also eliminate allot of this discussion. You would still have mechanical control of the surfaces, and the servos would simply be aiding the deflection of the surfaces--maybe to reduce load (not that there is allot anyway). Just an idea.

       Sure, but the underlying issue (how to make sure there is nothing like an autopilot or "corner programmer") is not solved.

     We are already, and almost always have been, single-string when it comes to redundancy. Purely mechanical systems fail pretty frequently, although it got a lot better after we starting using ball links instead of soldered washers. This doesn't seem any worse in that regard.

    I don't think this is a safety issue in the normal sense. Safety of the airplane, maybe, but not safety in the sense that it raises the risk to people outside the circle. We accept RC, that's also non-redundant for most of the parts, and there's absolutely nothing aside from luck that keeps them from crashing into crowds.

    Brett
Title: Re: Fly-by-wire bell crank assembly
Post by: Brett Buck on May 29, 2014, 12:45:07 AM
Maybe it should go in the CLPA section instead of General?

I still there is a big issue somewhere in the notion of a proposal, something that stopped cold previous efforts with some people I know.  I will ask them and see if they remember the issue.

   I think I and several others suggested this for FAI in the mid-late 90's, but it either never made it, or it was put in and then taken out later. Who can tell with FAI?  Somewhat later it was a proposal for AMA but it didn't get past the screening vote, as I recall. I think Tom Dixon wrote it, and it was probably dumped after wails of anguish about ZTron and the vast, diabolical, and of course mythical conspiracy to "Get Windy" from Windy's acolytes. No one cared about fly-by-wire at the time but I think they care now. The whole thing used to be documented on SSW but I think that is one of the missing threads.

  I would note that I am not planning on actually submitting such a proposal, merely showing that you could very easily write something that would eliminate fly-by-wire systems if you were so inclined. I actually don't think fly-by-wire *should* be banned, it's everything else you could do with it that needs to be dealt with. Unfortunately, no one has come up with a way to allow simple fly-by-wire while assuring that autopilots ARE banned.

     Brett


p.s. Try here, one of the few threads I have actually started myself:

http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=54944&mesg_id=54944
Title: Re: Fly-by-wire bell crank assembly
Post by: Tim Wescott on May 29, 2014, 09:20:26 AM
Unfortunately, no one has come up with a way to allow simple fly-by-wire while assuring that autopilots ARE banned.

It's as easy and as difficult as making the builder of the model rule verifiable: just ask the pilot.