Official Freewing 90mm F-4 Phantom II Thread

[Evan D]

On my radio I can have where there are separate trims for different functions and if flaps cause a roll I have were the flap lever changes the roll trim as flaps go up and down. Simple as a click in my radios trim function.

But that is only a last resort after making sure flap travel is identical.

[GliderGuy]

Yep! As we stated…regarding the gyro.

It’s a forgiving bird. I had the rudder servo jam at full throw when I did my 180 degree turn around from taxi to take-off heading a few weeks ago.

As you say, she wanted to roll, but the aileron compensated. After I settled down and realized she could still fly, brought her in for a landing.

Rudder servo was replaced before the next flight.

Love the F-4

-GG

[locharrow]

Well, I found out today the gyro does not compensate for trim!! Took off half flap as usual, gear up OK...flaps up ... wanted to roll right in a big way. Put in left trim which sort of half fixed it but still having to hold a lot of left stick. Flew a couple of passes but not pleasant. I had planned to land into the wind on the short football pitch but that would mean flying the crippled crate " good phrase that " low over guys building houses so chose a downwind half flap fast-ish landing. . Put the flaps down and lo and behold it started to behave a lot better. Landed OK, fast but fine and I taxied it back to the car. Raised the flaps and the left one stayed down. I thought it would be a pull apart job but it turned out to be just a faulty connector on the board, fairly easy fix so onwards and upwards ....

[locharrow]

https://m.youtube.com/watch?v=2ZdScd...UJTG9jaGFycm93 Well they shifted the goal posts to the middle of my take off and landing strip so I might add a battery operated grinder to my flight box ….😎

[Evan D]

I remember your posts...

[locharrow]

E D , I was flying around in some kind of safety mode last week when it would not let me roll so I wont be there again!!

Another great flying morning, light grey sky and park to myself. Did all the trims that needed doing after last flight. I set the battery back 1/4" from my usual mark. I was expecting to use trim to bring the nose down but it settled into nice level flight after flaps up. Very pleased with the set up now, if it gets any better I will try landing between the goal posts ! ...

[Evan D]

I gyro counteracts bumps so it won't level out the plane. If you have a self leveling gyro (SAFE) then in that mode it will.

[GliderGuy]

Hi Locharrow,

I had a PJ-50 flap horn working loose. So I was getting a slight asymmetric flap deployment.

I can tell you from experience that the gyro DID NOT stop the slight roll. It may have reduced the amount of toll, but she still rolled. Maybe because I had the gyro gain at 30 to 40%. A higher setting may have locked down the roll….probably would have.

Others with more gyro knowledge will need to add their comments.

-GG

[locharrow]

GG, if I use half flap on take off and it is in trim then on landing come through half flap to full flap and the plane dips a wing, how does the gyro know whether it was a gust of wind or one flap a few degrees out of trim? Would the gyro not bring it back to level fight using ailerons to compensate or is the gyro only a single momentary correction? Just asking, don't have the problem. !

[GliderGuy]

Gentlemen,hipeothitile hypathitilechypotheatrice ..a wee question. While making adjustments to my flaps it crossed my mind that if one flap was a bit more effective would the gyro correct any bank induced by the discrepancy?

No sir….it is not the way they function.
The gyro will counter gust upsets and dynamic instability. It won’t fix out-of-rig planes. Rig/trim manually as always.

-GG

[Elbee]

LA, Hypothetice loquendo. Best, LB

[locharrow]

Gentlemen,hipeothitile hypathitilechypotheatrice ..a wee question. While making adjustments to my flaps it crossed my mind that if one flap was a bit more effective would the gyro correct any bank induced by the discrepancy?

[locharrow]

Just grabbed a quick flight with the switch at the correct position.... I forgot how agile this F4 is! Nearly had heart attack after yesterday's sedate fly round! Needs a few wee adjustments but it flies very smoothly, not a lot of wind but enough to know the difference with the gyro.

[Elbee]

I would love to get the F4

CC, Just Do It. Best, LB

[Evan D]

I still have the original servo and it's mounting. I did upgrade the pushrod and links.

[locharrow]

C…..there is very little you have to do…..stronger pushrod and as far as the servo is concerned I put in good standard size analog servo and it’s been in for several years now without any trouble. I’m a simple old codger and if I can do it……….anyone can do it. 🥸

[Coconut]

Good news, it live to fly another day. I would love to get the F4. I'm just hesitant to do the elevator modification.

[locharrow]

Spot on…C.

[Coconut]

Gyro has SAFE that won't allow it to roll?

[locharrow]

Great flying day today so out with the F4...No one at the park and the grass newly cut. Changed the model on the tx to F4 got a switch warning as usual for gyro switch sorted that by throwing the switch and it was good to go. All surfaces behaving. Threw the gyro switch back to normal and taxied out. Power up and it lifted off very smoothly. Let it get out a fair bit then gently banked round for a fast diving run to pull up into a vertical roll. Pulled up not too bad but it simply would not roll. Brought it back down a bit and flew a very gentle pattern, landed like a dream and taxied back to the car.

This is a quizz...............