sskianpour

My Feedback: (2)

Hi guys,

I remember Jack Diaz and dad posting ideal throws (especially mild up trim on aileron for washout effect) but I cannot find the thread anywhere. Can anybody point me to that posting or would Jack Diaz Sr or Jr post it again please! I of course have the manual and realize there are throws included in there but I was hoping for he "experts"!!!!!

P.S. I have the fowler flaps

Thanks in advance!


Shaz

smchale

My Feedback: (67)

http://www.rcjetaddiction.com/forum/...6-80-with-gyro

And

http://www.rcuniverse.com/forum/m_11...m.htm#11290223

[8D]

Greg Wright

My Feedback: (6)

Hey Shaz,

The ailerons need to have an 1/8" of up in them for the washout. We just test flew mine about a month ago and i don't remember the throws that we set up. The other thing that Jack Diaz Sr said is to make sure to balance it for the C.G with the wings off and everything else in the fuse with the U.A.T full. It should balance right on the main spar slot.

sskianpour

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Thanks Greg! Main carbon blade or main aluminum tube for CG balance?
I want to make aure I am crystal clear!
Shaz

Jack Diaz

My Feedback: (1)

Hey Shaz, I am here

The CG, with the airplane RTF and no wings, should be under the main carbon spar slot at the fuselage.

These are the throws that I use:
Elevators: 1" up and down
Ailerons: 1.25" up and 1" down (measured at the flap edge).
Rudder: 1.5" each side.

Carefully check the "neutral" position of the ailerons (using a straight edge, and viewing from the side). Once satisfied, raise them 1/8".
Note that this could end up being more than 1/8" with respect to the flaps. What happens is that most times the fouler flap mechanism doesn't allow the flap to go fully up (it doesn't matter ... and helps!).
So, if you adjust the ailerons using the flaps as reference, you could end up without the necessary washout. This is Very important.
Without the proper washout (again: 1/8" more than the built in one), the Sabre could be tricky sometimes.

Let me know if you need any other info.

Jack

sskianpour

My Feedback: (2)

Ahhh,the cavalry has arrived. Thanks Jack, and everybody else. I am good to go!

Shaz

sskianpour

My Feedback: (2)

Wait, Jack...1/8" measured from the fuselage side or the wingtip side of the aileron?

Also, I have about 22-25 degres flap dialed in for takeoff as we are at 5500 feet and "lift" is non-existent up here. Any problem with that???

Thanks!

Shaz

Jack Diaz

My Feedback: (1)

Shaz, 1/8" measured at the inboard end.

I also fly at 5000+ feet (density altitude).
There is no problem with take off, and I find landings easier than at lower altitudes (better sink rate). Nose up, full flaps, speed brakes and power

The tendency to stall is another story. Be gentle with the elevator; and in your location, the extra washout is a must !!!
Advise: during maneuvers like loops or reverse cuban 8's, never reduce the power until the nose is pointing down (say 2 o'clock position). It bites if you reduce the power prematurely at your altitude.
You will be reminded if you forget this

Not the subject, but since I mentioned Density Altitude, here is a good D. A. Calculator. Useful also to calculate the power loss due to ambient conditions.

http://wahiduddin.net/calc/calc_da.htm

http://wahiduddin.net/calc/calc_hp_dp.htm

Jack

smchale

My Feedback: (67)

Jack,
This is great input. I'm scribbling down anything I can get my hands on regarding this model as I too am building one currently. Thanks for sharing your experience! The build is going pretty smooth and everything seems to be fitting...and there is a lot to get in there.
Btw, I fly at around 400'.

Tom Antlfinger

My Feedback: (24)

Hi Shaz:

Like Jack says, be careful with slow airspeed, hi-G maneuvers like loop, reverse Cuban, and Split-S.......

I personally never do this with my Sabre, since I have never seen Bob Hoover or Snod do these in their show routines.....just beautiful rolls and some 1/2 loops with roll out to straight and level at the top......if you do get into a low or high speed stall in a Sabre with the swept wing and relatively low rudder authority,especially at low speed, a grave yard spiral or spin is waiting to bite you....

Here is the old classic video of Bob H. just finessing that Sabre like no one else.....I try my best to emulate him, but seldom look as smooth as he does.....

I am thinking about putting a 180RX in mine so I can do those super cool rolls on take-off......my Titan is a little wimpy....

http://www.youtube.com/watch?v=TRt6UnNzR6I

TA

Jack Diaz

My Feedback: (1)

Hi Tom, good post, but 180RX ????? Be careful. A wimpy Titan is way more than needed !!

When you mentioned the low rudder authority, I remembered another hint:

The "rudder to aileron mix" on the Sabre for knife edges or slow rolls, is opposite to all other airplanes that I have programmed.
I mean: if you apply left rudder during knife edge, the airplane will roll right [X(]. So, the mix has to reduce the aileron deflection (during rolls).

I don't know why this happens, but when you look at how high the rudder is with respect to the wing, it makes sense !!! Rudder applies a torque.
But then, why other airplanes with tall rudders don't do it ?

Expert opinions are welcome

jack

Ron Stahl

My Feedback: (12)

Jack it must have the same aero properties as the old TopFlite Contender. I just got a mini one for playing around with and it does the same thing left rudder gives right rolls, and vice verse. I am so looking forward to building my 80" Sabre.

Tom Antlfinger

My Feedback: (24)

It just depends on how soon after liftoff that you want to start one of those down and 1/2 dirty Bob Hoover slow rolls....

Tom