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-   -   2 Post flight questions.. (https://www.rcuniverse.com/forum/rc-jets-120/8897941-2-post-flight-questions.html)

Pete737 07-01-2009 12:03 PM

2 Post flight questions..
 
It's a bit difficult to acurately diagnose what I believed to be possible issues with my F-16....Not ever having flown another jet but here' goes anyway.

-The ailerons felt weird, Both Jeff and I thought so, Jeff more importantly having flown 16's for 10 years or so. They seemed to "wander" a bit if that's the right term. Sometimes they would roll faster than others given identical input, If you saw the video, after takeoff halfway through the downwind there were 2 sharp rolls to the right, Those rolls were a result of the same aileron imput I gave later in the flight, Which had much milder re****s. I have 20% expo running 5645's. I don't know if that little bit of slop in the 5645 has anything to do with it, I plan to change them to 5955's anyway.

-The stabs are not flush with the speedbrakes, The airplane needed about 10 clicks of up elevator for straight and level flight. The TE of the stabs are roughly 3/8" above the speedbrake. Jeff thinks its slightly nose heavy, CG is at 155mm right now. On that note, If I was willing to live with the CG situation which I probably am because the elevator feels great, How do you think the addition of a pilot would affect things?

Thanks! Pete


Shok 07-01-2009 12:12 PM

RE: 2 Post flight questions..
 
The up trimmed stab is pretty normal for straight flight on the 16


Check that your ailerons are not drooping any, and both sitting even with the te of the wing at 0 trim.
Sometimes if one is drooping a bit, it will want to wander

Pete737 07-01-2009 12:20 PM

RE: 2 Post flight questions..
 
Thanks Ronnie, I will check that ASAP. Do you think this could be caused by the 5645?

Pete

Shok 07-01-2009 12:22 PM

RE: 2 Post flight questions..
 
Sorry, no idea, I never used those

Pete737 07-01-2009 12:24 PM

RE: 2 Post flight questions..
 
Ok, Just asked because there seems to be a love hate relationship with those servos.

Pete

Vincent 07-01-2009 12:37 PM

RE: 2 Post flight questions..
 
Add more expo...maybe 35% and or reduce the travel by 10%.
V..

FalconWings 07-01-2009 01:03 PM

RE: 2 Post flight questions..
 
Strange, very strange. I use 5645's on flaps only, and with the speed dailed down to 50%. They do seem to run a little rough, but I wouldn't expect what you experienced either.
Give it another try with any servo's you have that you know are good. You really don't need much torque at all on ailerons.

lov2flyrc 07-01-2009 01:11 PM

RE: 2 Post flight questions..
 
Dump the 5645's, they are know for poor centering and spongy feel. Personally, I would never use a hitec servo again... Swap out for a JR 3421 or 9411 and your problem will vanish....
JMO

Pete737 07-01-2009 01:57 PM

RE: 2 Post flight questions..
 
Ya see, I hear from some that the 5645's are fine, Others say they are paper weights. Im am a Hitec guy so I am going to the 5955's on the ailerons and I'll let you know what happens after capitol jets.

Thanks for the ideas, Pete

NickC5FE 07-01-2009 02:40 PM

RE: 2 Post flight questions..
 
What Todd says is pretty accurate i think. Also, usually, f-16s work great with the stab at neutral almost at the bottom of the strake at the leading edge of the stab...Just my .02

lov2flyrc 07-01-2009 03:11 PM

RE: 2 Post flight questions..
 


ORIGINAL: Pete737

Ya see, I hear from some that the 5645's are fine, Others say they are paper weights. Im am a Hitec guy so I am going to the 5955's on the ailerons and I'll let you know what happens after capitol jets.

Thanks for the ideas, Pete

Try swapping Hitec for JR and you will no longer be a "Hitec Guy" ;) You dont know what your missing!

Pete737 07-01-2009 03:17 PM

RE: 2 Post flight questions..
 


ORIGINAL: lov2flyrc



ORIGINAL: Pete737

Ya see, I hear from some that the 5645's are fine, Others say they are paper weights. Im am a Hitec guy so I am going to the 5955's on the ailerons and I'll let you know what happens after capitol jets.

Thanks for the ideas, Pete

Try swapping Hitec for JR and you will no longer be a ''Hitec Guy'' ;) You dont know what your missing!
:) Well Im sure you know more then me but I love the 5955's and every other Hitec Ive used except for the 5645..

Pete

Pete737 07-01-2009 03:19 PM

RE: 2 Post flight questions..
 
Wait a minute though.. I forgot all about my TF cessna 310, I have a 5645 on the elevator and that feels fine?? Weird..

Pete

Vincent 07-01-2009 04:08 PM

RE: 2 Post flight questions..
 
Pete,
I would agree with Todd, the centering could be the issue. I have used DS3421`s in many jets and its a superb servo for that job. I am running them right now on ailerons and rudder in my FB Mig-21, 100flights and counting. My Tams A-4 has 3421`s on every surface and 140flights with no issues, my BVM F-86 the same.
V..

lov2flyrc 07-01-2009 04:09 PM

RE: 2 Post flight questions..
 
you can only lead a horse to water.....;)

Square Nozzle 07-01-2009 04:17 PM

RE: 2 Post flight questions..
 
As I recall, Pete has a Futaba radio. Any issues running a JR servo with Futaba? I Think only the connector will be a concern but I'm only guessing since I run only JR in my JR system.

sailing1 07-01-2009 04:39 PM

RE: 2 Post flight questions..
 
Pete,
I would just swap out the 5645's for the 5955's and it will probably solve your problem. The 5645 is ok for smaller prop 3D and scale models or for something like the flaps where you need some grunt but are not as particular about the centering. I put 7955's in the tail of my Aviation Design F-16 and they seem to work fine. I have JR 8611's in my Boomerang and they work just as well but not any better (at least to me). On the plus side it is so much easier to set up the internal linkages for the elevators using the 7955's that can be programmed. I haven't been into jets all that long so can't comment on how long servos last for this applicaiton. But I can tell you that my 3 year old 35% Wild Hare Sukhoi is on it's original set of 5955's with no failures or gear slop and that I have already had to replace the gears in the JR 8611's in the tail of my 35% Comp Arf Extra due to gear wear after only one year. In the end run I think you are pretty much shooting yourself in the foot if you try to set up something as fast and expensive as a Jet with anything less than the best servo offered by JR, Hitec, Futaba or whoever you feel comfortable with. Just my 2 cents worth.

lov2flyrc 07-01-2009 04:52 PM

RE: 2 Post flight questions..
 


ORIGINAL: Square Nozzle

As I recall, Pete has a Futaba radio. Any issues running a JR servo with Futaba? I Think only the connector will be a concern but I'm only guessing since I run only JR in my JR system.
No issues using JR Servos with Futaba (I fly futaba myself)


Pete737 07-01-2009 05:05 PM

RE: 2 Post flight questions..
 
Well Ive got 2 5955's coming. That should take care of it...

Oh, One more thing, For the maiden my main gear doors didn't close, Both of them hung wide open, So we put the gear back down..

Is there a max operating speed for the gear on a 16? Jeff was well into the flight before we attempted to bring the gear up, Probably doing around 110-120mph or so, Just guessing. Probably close though.

Thanks! Pete

Mavrik! 07-01-2009 05:26 PM

RE: 2 Post flight questions..
 
Pete,

What F16 do you have? Sorry I might have missed it? I have a FE F 16 and my main doos sometimes stay open after gear up comand. I think this is due to speed at time of gear up and not enough PSI in tank. I find if I slow the jet the doors close and they then stay closed. The leverage point in the first part of ram travel is not much, but once closed the leverage angle changes and it is able to stay closed. Also I fly with a tad of up on the elevator as well. Oh JR 9711's on elevators bought from Todd!! :)

the F16 is my first and only scale Jet. I must say I love the way it flies and have no need for any other scale jet!

Mav

Pete737 07-01-2009 06:19 PM

RE: 2 Post flight questions..
 
Hi Mav!

Its a skymaster and I have a slight leak on gear down, Nothing on gear up though. I probably should have topped it off before takeoff, the nose gear door did close though. Next time Ill try it with a higher PSI and pull it up just after lift off. The 16 Is my first jet and happens to be scale but I have an insane need for more :D.

Pete

Guillermo Ibanez 07-01-2009 08:49 PM

RE: 2 Post flight questions..
 


ORIGINAL: Pete737

It's a bit difficult to acurately diagnose what I believed to be possible issues with my F-16....Not ever having flown another jet but here' goes anyway.

-The ailerons felt weird, Both Jeff and I thought so, Jeff more importantly having flown 16's for 10 years or so. They seemed to ''wander'' a bit if that's the right term. Sometimes they would roll faster than others given identical input, If you saw the video, after takeoff halfway through the downwind there were 2 sharp rolls to the right, Those rolls were a result of the same aileron imput I gave later in the flight, Which had much milder re****s. I have 20% expo running 5645's. I don't know if that little bit of slop in the 5645 has anything to do with it, I plan to change them to 5955's anyway.

-The stabs are not flush with the speedbrakes, The airplane needed about 10 clicks of up elevator for straight and level flight. The TE of the stabs are roughly 3/8'' above the speedbrake. Jeff thinks its slightly nose heavy, CG is at 155mm right now. On that note, If I was willing to live with the CG situation which I probably am because the elevator feels great, How do you think the addition of a pilot would affect things?

Thanks! Pete


Hi Pete:

Like you, I am about to maiden my new SM F-16 1/8 after a fatal crash on Aug. 10, 2008.

Regarding your question about CG, read this thread:

http://www.rcuniverse.com/forum/m_77...tm.htm#8280992

About your ailerons, has you set aileron differential as stated in the manual?

Pleas post your maiden flight video

Guillermo

Pete737 07-01-2009 09:14 PM

RE: 2 Post flight questions..
 
Hey Guillermo,

I don't have any aileron differential, I was informed that it was not necessary on the F-16. I did see how the model dives in a steep turn although I did not find it that frighting.

Im pretty happy with how it flew other than the roll situation so I think Ill leave it alone for now and get more time on it. Remember though, This was my first turbine flight so take my advise with a grain of salt ;)

Heres the vid:

Pete

[youtube]http://www.youtube.com/watch?v=7fqCJI-MLvY[/youtube]


Guillermo Ibanez 07-01-2009 09:38 PM

RE: 2 Post flight questions..
 


ORIGINAL: Pete737

Hey Guillermo,

I don't have any aileron differential, I was informed that it was not necessary on the F-16. I did see how the model dives in a steep turn although I did not find it that frighting.

Im pretty happy with how it flew other than the roll situation so I think Ill leave it alone for now and get more time on it. Remember though, This was my first turbine flight so take my advise with a grain of salt ;)

Heres the vid:

Pete

[youtube]http://www.youtube.com/watch?v=7fqCJI-MLvY[/youtube]


Hey Pete:

Nice video

Congratulations

Nice Jet and nice flight

Hope my maiden will succeed as yours.

FalconWings 07-01-2009 09:45 PM

RE: 2 Post flight questions..
 
I actually trust the tialerons of my TJ F-16 to 5955's and they are really good servos. I used to have JR 9411's but they were not cutting it, so I went for the extra juice of the 5995s. I'm a happy Hi-Tec guy. [8D]

JR is also ok, although you see all these $20K+ models go down and guess which servo brand the pilots where using. ;)


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