Line rake, line length and line diameter.

[Will Moore]

Yatsenko Sharks have no lead out adjustment. Do they test fly their Sharks using specific line lengths and diameter, and if they do, does anyone know what it is?  And since they have no lead out rake adjustment, does it change the trim of the airplane if you use different diameter lines and lengths. For example, go from .018 9 or 6 strand to .012 solids, or 64 feet eye to eye versus 62 ft eye to eye?

[Tim Wescott]

I'm trying to cut down on answers that involve lots of supposition, but you asked in the other thread, so:

For anything other than a Yatsenko, yes, in general, changing line diameter or the length, or even significantly changing the speed of the aircraft would change the desired leadout position.  But I don't know why the Yatsenkos feel they can ship with fixed leadouts, nor do I know if they've done some other magic -- hence, no answers so far.

Maybe someone who does fly Yatsenkos, or are otherwise familiar with them, can answer?

[Will Moore]

Thanks Tim. I sent an e-mail to the Yatsenko's and asked the question. Will be interesting to see what they say.

[Bob Whitely]

Yatsenko planes are trimmed to the nth degree, period. They are ready to go at the highest level. There are maybe
three or four guys in the world, and I am not one of them, that could possibly improve on them. RJ

[Will Moore]

So, I just heard back from them. yuri says they normally use maximum line length and .4 mm lines. And they say that electric guys ( and mine is electric), tend to use .45mm lines because they think it is smoother and better for electric. They do not feel that line length and thickness acts a lot to effect the trimming of the airplane and flight characteristics.  I didn't do the conversions as to what .4mm and .45mm are in inches. I'm using .018 braided , 66ft eye to eye right now. And I have been advised not to use solids in Florida because of static shock concerns.  Model flies with no perceivable trim issues, though I could be wrong. And I am using Igor's timer which I am very pleased with.  I was just wondering......

[Trostle]

And I have been advised not to use solids in Florida because of static shock concerns.  ......

It would be interesting to know why solid should not be used "in Florida because of static shock concerns."  Why would steel solids be any worse than steel cables?

Keith

[bob whitney]

 all AMA and FAI speed planes flown in Florida are flown on Solid lined .also many of the racing planes

[Brett Buck]

So, I just heard back from them. yuri says they normally use maximum line length and .4 mm lines. And they say that electric guys ( and mine is electric), tend to use .45mm lines because they think it is smoother and better for electric. They do not feel that line length and thickness acts a lot to effect the trimming of the airplane and flight characteristics.  I didn't do the conversions as to what .4mm and .45mm are in inches. I'm using .018 braided , 66ft eye to eye right now. And I have been advised not to use solids in Florida because of static shock concerns.  Model flies with no perceivable trim issues, though I could be wrong. And I am using Igor's timer which I am very pleased with.  I was just wondering......

   0.4 mm is .0157" and 0.45 mm is .0177", so not that far off.

    Yuri is wrong, even slight changes in the line dimensions makes a big difference. He may not be aware of that since the leadouts are fixed. They are probably OK for tipweight since they seem to be very insensitive to tipweight changes and they come with more tipweight than I would use. For electric, I would expect the leadouts to be much too far forward, based on Paul's experience.

      They had a small amount of trouble using the 0.018 lines that I gave them at the 2004 NATs.

      Brett

[Brett Buck]

 all AMA and FAI speed planes flown in Florida are flown on Solid lined .also many of the racing planes

   I would expect that the problem is the same problem we have everywhere else, aside from the desert - that the humidity tends to cause them to stick together like they were welded, with a few twists in them.

     I would also expect that the voltage gradient in Florida in the summer due to the frequent afternoon heating thunderstorms would be daunting, but solids are no more prone to it than stranded.

      Brett

[Paul Smith]

Maybe the thinking is that somebody who would BUY rather than BUILD a model airplane shouldn't be messing with the professional setup.

[Will Moore]

Yatsenko planes are trimmed to the nth degree, period. They are ready to go at the highest level. There are maybe
three or four guys in the world, and I am not one of them, that could possibly improve on them. RJ

Maybe the thinking is that somebody who would BUY rather than BUILD a model airplane shouldn't be messing with the professional setup.

Paul,
 They designed mine with the electric power system I sent and recommended to them. It was the first electric Shark they did.  We did it as a joint effort to continue to move electric propulsion forward. Obviously they changed all the construction under the hood .  But there are aspects of trim the end user can alter, like center of gravity and control ratio.  So the "professional" setup, as you call it, is not altogether cut in stone.  So they do not mind you "messing" with it, and the Yatsenkos do not feel leadout rake adjustment is all that critical.  Just as tip weight does not seem critical, maybe line rake isn't either.

Bob Whitely is absolutely correct. These guys know their designs and these airplanes do fly at the highest level.
I'm with Bob, I don't think I could make further improvement on the trim, as it is pretty much locked on to almost perfect already.

[Tim Wescott]

Maybe the thinking is that somebody who would BUY rather than BUILD a model airplane shouldn't be messing with the professional setup.

Yup, no one flying those pre-built things could ever be competitive.  'cept maybe the current world champion.  Who probably knows what he's doing, or he wouldn't be the world champion.

[PJ Rowland]

Having seen almost every variation of the Yatsenko design and been beaten by a few of them myself I will say this.

They are good.  but not perfect.  Even at the World champs there were similarities between the sharks in their turn rate presentation.  Even the Wchs plane wasnt perfect but its amount of errors you can see which determines the places.

Very few mistakes in the pattern.

[Randy Cuberly]

HHHmmmm....Could it be that a lot of it is determined by how tight the NUT on the handle is!   

I'm a big fan of trimming an airplane to fly exactly the way YOU as an individual want to fly...BUT, I've seen some really good patterns flown by people with airplanes that in my opinion were in very poor trim...All up to the NUT!

Try explaining 570+ patterns flown with a Ringmaster!  The NUT on that handle is very, very tight! 

Randy Cuberly

[Tim Wescott]

HHHmmmm....Could it be that a lot of it is determined by how tight the NUT on the handle is!   

Could be!

I'm a big fan of trimming an airplane to fly exactly the way YOU as an individual want to fly...BUT, I've seen some really good patterns flown by people with airplanes that in my opinion were in very poor trim...All up to the NUT!

Try explaining 570+ patterns flown with a Ringmaster!  The NUT on that handle is very, very tight! 

But how good could the flight have been with a really well-trimmed airplane?  I know that I can do pretty well with a Ringmaster, and then do about 30 points better with a well-trimmed Fancherized Twister -- and better yet with a hand-me-down from Paul Walker.