Official Freewing 90mm F-4 Phantom II Thread

[DCORSAIR]

I did some more research…prompted by your comments. I could not find the article that I’d read which suggested the “leave 40%”. All the articles and videos I can now locate say “leave 20%” and/or consider 3.5V per cell the minimum.

Percentage is subjective anyway. It is the minimum 3.5V that really matters per the experts. Going lower risks hitting the 3V “damaged” cell voltage.

But, I fly many thousands of flights a year, so I must treat them easy. And I get a year on a new set by rotating 10 batteries through 4 EDFs to achieve this large number of flights on a set. The annual cost of 10 LiPos is still cheaper than a lot of hobbies!

Finally, Most importantly, I prefer to keep a good safety margin for go arounds, too.

I am updating my mental database. 😃

-GG

Oh I understand and was just adding a little humor, when I first got into EDF jets I didn't understand all the battery tech stuff but soon learned the hard way, I don't shop around for the cheapest battery either and by paying a little more for my GA lipos I have found you do get what you pay for, I have abused these poor batteries and like I said, 4 yrs on some and getting close to 5 yrs on a a couple of them and still using them in my HSD 120mm T-33 which eats batteries for lunch, still flying them in my big scale helis as well, but 30% or less is the normal for me, I just can't stop flying at 40%, I take off again with that much left in the tank , but I see your point if I flew that many flights.

[GliderGuy]

I did some more research…prompted by your comments. I could not find the article that I’d read which suggested the “leave 40%”. All the articles and videos I can now locate say “leave 20%” and/or consider 3.5V per cell the minimum.

Percentage is subjective anyway. It is the minimum 3.5V that really matters per the experts. Going lower risks hitting the 3V “damaged” cell voltage.

But, I fly many thousands of flights a year, so I must treat them easy. And I get a year on a new set by rotating 10 batteries through 4 EDFs to achieve this large number of flights on a set. The annual cost of 10 LiPos is still cheaper than a lot of hobbies!

Finally, Most importantly, I prefer to keep a good safety margin for go arounds, too.

I am updating my mental database. 😃

-GG

[DCORSAIR]

You can SLOW flight, but she’s a jet! Why?

I fly only 3:30 to have an emergency reserve.

LiPos will last a lot longer if you stop at a low voltage of 3.8 V (about 40% left in the tank).

Good idea for several reasons to stay at 3:30 in my opinion. I fly 6000s SMC and Admiral

B-2 = 5 min
AL37 = 4:30
PJ50 = 4 but I hot rod this bird
F-4 = 3:30

If you would fly these at 25% power only, you could extend all of them. But….THEY ARE JETS!!! Why?

-GG

Wow 40% left in your batteries, I got batteries 4 yrs old and have been ran down to 14% several times by accident, my normal is about 30%, still flying them today, not puffy but starting to get a little soft, I won't name the brand so I don't start a brand war, I have proof that you can go lower than 40% , if I stayed at 40% I would get 10yrs...

[Evan D]

I post many times that we time our flights many different ways. Like GG I taxi out (paved taxi/ runway so not using a lot of power) and before taking off I reset the timer which starts at 15% throttle and continues running. I have a voice time remaining call out whenever I go to idle and at one minute a warning. At the one minute I begin the set up to land and usually touch down as my timer goes off.

[GliderGuy]

I start my timer and take off immediately, no taxi time. I am flying a full 3:30…you are not.

You have 3 choices then….to fly longer:

1) fly slow.
2) Start your timer later or increase it to compensate for taxi time. Not much power is being used during taxi.
3) install a more efficient motor…there are choices to be made from. Others will need to comment.

-GG

[locharrow]

GG......I may have given the wrong info,.....the timing starts when I switch on TX, I then plug in and taxi out 50yards or so then take off. Warning is set at 3.30 min. when I set up to land. That is "my" 4 min.. I was hoping that I could extend that a wee bit as it galls me to have to land because it is great watching it fly.
I get 6-8 minutes on my 4000s in the FMS Pitts but don't have the same "don't want to land" feeling!
:f4::punch:

[GliderGuy]

Without getting teknikal guys, on HRB 6000s I'm flying 4 minutes at varied speeds. Batteries read out, when re-charging, around 3.8 most cells quite consistently. Without getting to the point of no return, is there another half minute to be found in them ...or even a full minute. Now bear in mind I am VERY old and my brain is mince so keep it SIMPLE !! :f4::punch: (please)

You can SLOW flight, but she’s a jet! Why?

I fly only 3:30 to have an emergency reserve.

LiPos will last a lot longer if you stop at a low voltage of 3.8 V (about 40% left in the tank).

Good idea for several reasons to stay at 3:30 in my opinion. I fly 6000s SMC and Admiral

B-2 = 5 min
AL37 = 4:30
PJ50 = 4 but I hot rod this bird
F-4 = 3:30

If you would fly these at 25% power only, you could extend all of them. But….THEY ARE JETS!!! Why?

-GG

[locharrow]

Without getting teknikal guys, on HRB 6000s I'm flying 4 minutes at varied speeds. Batteries read out, when re-charging, around 3.8 most cells quite consistently. Without getting to the point of no return, is there another half minute to be found in them ...or even a full minute. Now bear in mind I am VERY old and my brain is mince so keep it SIMPLE !! :f4::punch: (please)

[GliderGuy]

Well, I like to keep it simple. I just grabbed it's neck and said "now listen jack straighten up and fly right". Seemed to work, good flight yesterday, no trouble at all. :f4::punch:

That works best for me when I grab the neck of the reflection I see in a mirror.

-GG

[Elbee]

locharrow

[locharrow]

Well, I like to keep it simple. I just grabbed it's neck and said "now listen jack straighten up and fly right". Seemed to work, good flight yesterday, no trouble at all. :f4::punch:

[Evan D]

Usually I will put in the recommended elevator to flap mix and fly it with normal trims, not on F-Mode. If I find flaps cause more or less elevator compensation I'll just put it in the mix. If I note a roll with flaps that's when I go in and to the F-Mode as you are saying. I keep flaps on a slider and it's nice how it keeps the trim proportional as you apply or reduce flaps.

[Hugh Wiedman]

Well, I found out today the gyro does not compensate for trim!! Took off half flap as usual, gear up OK...flaps up :face_with_symbols_o... 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 ....:f4::punch:

I agree with Evan D. I have every aircraft with flaps set up that way. On a Spektrum transmitter, that ability is found under F-Mode setup (not to be confused with gyro Flight Modes set up with a Spektrum RX), where you assign Flight Modes to a switch, in this case, I assign that switch as D, which is my Flap switch. Then go down to Trim Setup and you can see each surface default set as unassigned. Next to the ailerons, I change it to F-Mode and even more important change the elevator to F-Mode. That way I can trim ail/ele at each flap setting and the trim is retained. Makes flying with flaps so much easier, but of course you are quite busy on the maiden trimming both Aileron and Elevator at each flap setting. When finished, the aircraft remains level as does the AoA at each flap setting.

[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 :face_with_symbols_o... 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 ....:f4::punch:

[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!! :scream:

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 ! ... :f4::punch:

[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.