Correct setup for Phantom II F4 - Throws, Dual Rates and Exponentials

[Cuichi]

Hello. I´m a begginer EDF Pilot, recently bought a Phanton Freewing II 90 mm EDF Jet, I would like to check with experienced Pilots of the same Jet, the Following :
1. If the Throws given in the Manual, specially for Elevator are correct, they seem to be somehow too high.
2. If using an Admiral RX with Gyro, the use of exponentials is recommended or no, and if yes how much to use.
3. If the use of Dual Rates is or not recommended,

[GliderGuy]

Hello. I´m a begginer EDF Pilot, recently bought a Phanton Freewing II 90 mm EDF Jet, I would like to check with experienced Pilots of the same Jet, the Following :

1. If the Throws given in the Manual, specially for Elevator are correct, they seem to be somehow too high.
2. If using an Admiral RX with Gyro, the use of exponentials is recommended or no, and if yes how much to use.
3. If the use of Dual Rates is or not recommended,

Take heed of the below, and you will VERY MUCH enjoy your F-4! I've ordered 3 of them (crashed 2 of them). The below will help you avoid the things that caused my 2 crashes. Bird #3 has been flying over a year with hundreds of flights on it:

• As a beginner EDF pilot, it is strongly suggested that you have an experienced EDF pilot do the maiden flights. The bird typically has a tendency to roll left after lift off. I set mine up by the book (no expo), and I am satisfied with the handling and response after I added some right aileron trim to account for the left roll tendency.
• The critical set-up is the amount of elevator/flap mixing....don't overdo this mixing.
• Ensure both elevators are aligned as the same angle each side and verify the amount of nose-up when the stick is neutral (nose up = leading edge of the elevator is down. Set this amount by the book.).
• Double check that the elevator servo is securely glued in. Some folks remove the elevator servo and add a bit of plywood around it then screw it to the plywood. I crashed bird #1 because the elevator servo came out of the socket (there was no glue in the socket...factory QC and I missed that one). Luckily, the crash damage was repairable.
• The elevator push rod and ball link have a propensity for breaking/bending which will cause a fatal crash. I have updated to a 4-40 threaded push rod and automotive grade/beefy ball link for the elevator. I lost the F-4 (#1 bird's second crash) because the elevator ball link broke.
  • If you don't want to wait, at least epoxy some carbon fiber tubing to the push rod and add some layers of hot glue to the outside edges of ball link structure to strengthen it and fill the "Y" gap in the ball link with hot glue (this is where it breaks). Also, put some heat shrink tubing around the servo arm end's white plastic retainer clip. This white clip can break and/or bend under flight stress and allow the push rod to disengage from the elevator servo arm.
    • Lots of stress on this elevator push rod during flight...so it seems and so others have reported in this blog.
  • If you lift the nose and smack the elevators on the ground, you can cause the servo arm's plastic teeth to slip on the servo actuator. I put a dot on the fuselage at the leading edge of the elevator so I can visually check the alignment prior to each flight. Also, any smack on the tail when loading/unloading can cause this to happen. I can tell you by experience, slipped teeth on the elevator servo arm will make your next take-off very EXCITING!
• Balance it by the book
• Order some extra Freewing 80/90mm EDF Nose Landing Gear Connecting Pin / you'll need these as they break on hard landings
  • On bird #3, I added a small steel skid plate to the bottom of the under-nose radome.
• Approach on final with a tiny bit of power then ease the power off once in ground effect....be prepared that if you chop the power the nose will drop. Chop the power close to the ground and things get interesting until you get used to this characteristic. Ease off the power as you enter ground effect.
• Add some hot-glue striping to the main landing gear doors (add this where it does not interfere with the fit of the gear door against the wing). Failure to do this will have you picking up pieces of the gear doors after a hard landing. The hot glue striping can be added to the "inside" of the gear door, if you are careful and pay attention to the gear closure fit. Or...put the hot glue on the outside of the door and not worry about where you put it.
• Check each/every control horn attachment to ensure they are securely glued to the control surface. Put some pressure on them. If you find an insecure control horn, add some hot glue to secure it.
• Take-off with no flaps and land with full flaps.
• If you are using a 5000 mAh battery, expect a 3 min to 3.5 min flight so you'll have reserve for a go-around....4 min is pushing it and you won't have much of a go-around reserve. This is with 1/2 throttle cruise and some acrobatics.
• Keep it fairly close initially because it will blend into the sky making it hard to keep yourself oriented to the bird's profile. You will have precious little time to re-orient yourself....it scoots along pretty fast.
• Add some clip-on RF chokes to each of the power leads going to and coming from the ESC. These high-current ESCs can generate common mode radio interference which might interfere with the hand-shake between the transmitter and receiver. Any length of wire between the ESC and the RF choke is an RF radiator. So, keep the chokes as close to the ESC as possible. I lost bird #2 due to a transmitter/receiver hand-shake loss. Since I've added the RF chokes to the bird #3, I've had ZERO radio issues with bird #3 and have flown bird #3 hundreds of times for over a year. Get the clip-on RF chokes from Amazon.
  • From Amazon.... Cedmon 20 Pieces Clip-on Ferrite Ring Core RFI EMI Noise Suppressor Cable Clip for 3mm/ 5mm/ 7mm/ 9mm/ 13mm Diameter Cable, Black

A little extra time setting-up per the above precautions will keep your bird in the air trouble free, and you won't be buying three of them.

Good luck,
Glider Guy

[Cuichi]

Thank you very much Glider Guy, your excellent advise is must appreciated, I already crashed mine on the Maiden Flight, because I did not thight one screw on the left elevator and it got loose, making the F4 uncontrolable, I was lucky the crash was not so bad and I was able to repair the Jet. I will print your reply and excecute each and every bullet on the same, I will post results on my new attempt. thanks again.

[Cuichi]

Hellooo , I wanted to let you know I took Glider´s Man Advise and implemented all his recommendations on my recently repaired Freewing Phantom F4 90 mm EDF. I also checked and corrected the Admiral Rx-Gyro compensation and corrected it, since compensation for Ailerons and Rudder was reversed. As a result, last sunday the airplane had it´s remaiden flight with me (Novice in Jets) as the Pilot, it took off perfectly and flew beautifully, very stable, responsive and fast, flew 3 minutes on a Admiral 5,000 Mah / 6S Battery, and landed softtly full flaps. I thank you again Glider Man and this Forum for such acomplishment. Regards.

[Elbee]

CG, Thank you very much for taking the time to add your experience to this thread. I will take your advice to task before my next outing with my Phantom. Bravo Zulu, Sir. Best, LB

[Cuichi]

My pleasure Lbee, I´m glad GM´s advise will also be of your benefit. Have great fun with your Phantom, it is a great airplane¡!

Regards,

Cuichi

[GliderGuy]

Cuichi and LB, I took this post over to the F-4 thread.

Cuichi....glad you had success on your re-maiden flight. Happy to have helped, even if just a little.

Cheers,
Glider Guy