Official Freewing 90mm F-4 Phantom II Thread

[Carlos G]

Hi SanExup,

Thank you for the link, this should help get things under control.

Carlos G

[GliderGuy]

Hi SanExup,

Thank you for the link, this should help get things under control.

Carlos G

Have you tried “S” turning to bleed off kinetic energy once on the ground and rolling? The wide gear of the F-4 allows for S-turning almost immediately after touch down.

S turns get it rapidly slower quickly.

Also, if your runway is wide enough, you can do a wide and looping turn at the end to keep from running off the end without worrying about a tip over.

I use S turns when I fly at one place that is somewhat short….250/300 ft long. It works like a charm. I never worry about running off the end.

How much to turn? Experiment! The tighter the S turns the quicker you slow down. But….you can still tip the jet over if you are too aggressive. No need to make rapid directional inputs…just nice and smooth back and forth about 2-3 seconds in each direction.

This is a technique I learned when flying an old J2 Piper Cub that had no brakes.

Caution: Be ready to abort and go around if you over shoot your approach. Get it on the ground as close to the approach end as possible.

Why does this technique work? it's all energy management. Consider the following:

• Turning increases the friction in the bearings...eats up energy
• Turning adds side forces to the rubber tires...eats up energy
• But...most importantly...when you are S turning, you are traveling a longer path vs rolling straight ahead. In effect, you create a longer runway when you are S turning
• Longer runway rolls (via S turns) give the opportunity for any head wind blowing to work on your F-4 and bleed off even more energy

-GG

PS As your speed slows, you can become more aggressive with the S turns because there is less chance of tipping over as the speed decreases. Your final S turns as you approach the far end can be quite steep...even to the point of being a 180 degree direction reversal.

[davegee]

Well, I got flight number 9 safely in the books today with my Freewing F-4. This is the first time I had everything going for it that I had planned from the beginning. I had the white nose on it (previously used an old black nosecone for test flying) redid the cockpit with the Motion RC cockpit kit, bought some new pilots through Chris Wolfe's parents' company that look much better than the stock ones, and also added RC Geek Chris' multi-burner afterburner simulator. Also added Chris' 3D printed afterburner nozzles that looked much better than the stock ones.

Man, was that cool seeing those afterburners light up on the takeoff roll, and when I did a low pass at near full throttle! Very impressed with them! Plus, I got my wife to paint the little pilot figures, including yellow helmets with the logo stickers I made up for VF-84 that I thought was pretty cool. Attached are some pics.

[T- Elbert]

Up to 318 flight on my SAE F-4 . 3 nose gears and one elevator servo. Finally got two of my buddies into F-4,s so now I’m not the only rhino jockey

[davegee]

Up to 318 flight on my SAE F-4 . 3 nose gears and one elevator servo. Finally got two of my buddies into F-4,s so now I’m not the only rhino jockey

Good for you! I hope someday I might even get halfway close to the number of flights that you have now! I doubt that will happen, but I'm having fun with each flight that I do.

Happy Landings!
davegee

[Hugh Wiedman]

davegee outstanding, especially now that it's flying as well as it's lookin! Soon it will be one of your favorite EDF's to fly. Rock On F-4's!

[davegee]

I’m diggin’ it so far, Hugh!!!

davegee

[Carlos G]

Hi GliderGuy,
Thank you for the suggestion. At this point in time I tend to bring the F-4 in to land a bit on the hot side, Not having much time on this bird I want to keep from stalling on landing. As I gain more time I maybe be able to find that "Edge" to slow down enough to try S turns. One problem we have at our field is that while the runway is 300ft long, it is only about 12ft wide. The S turn method may not be enough to scrub off the speed before reaching the end of the pavement. Another factor we have to deal with is the approach on both ends of the runway have a drop-off. The drop-off will get turbulent causing pitching on an approach to landing going into the wind. It is just one of the quirks of our field and you have to take it into account when flying at our field

[GliderGuy]

Hi Carlos, If I tried to land on a 12 foot wide runway, I'd be making "S" turns just to try to stay on it.

Your field does sound challenging.

Cheers,
GG

[P51DPLT]

Got my new to me F-4 out to the field for my first flights. 4 total and I really like the way it flies. If it looks good, it’ll fly good!

[Ron1950]

anyone try the 1900kv edf yet? i see it comes with the 1750.. just wondering as the 1900 90mm fan really woke up my stinger 90

[Elbee]

If it looks good, it’ll fly good!

PP, Truly nicely done. She must fly beautifully, cuz' she's a looker. Best, LB

[GliderGuy]

Got my new to me F-4 out to the field for my first flights. 4 total and I really like the way it flies. If it looks good, it’ll fly good!

A beauty!

To ensure it keeps flying, did you incorporate the suggested upgrades discussed in this thread? There are known weak areas that should be addressed.

Just curious….several have reported the need for right aileron trim right out of the box. Did yours require this?

-GG

[P51DPLT]

A beauty!

To ensure it keeps flying, did you incorporate the suggested upgrades discussed in this thread? There are known weak areas that should be addressed.

Just curious….several have reported the need for right aileron trim right out of the box. Did yours require this?

-GG

GG,

This airplane has been around for a while. I am at least the 3rd owner. I set it up by looking through the threads here and on RCG. I have pushed my CG to 195mm or so, put a carbon rod on the elevator servo, replaced that servo as well. I have not done anything else as of yet. I do have a couple extra nose gear pins as I saw that is a weak spot.

What else would you suggest?

Initial flights were on a 5000's giving my 3 mins of mixed throttle. I just got some 6500's to try next go. I am also planning on a repaint at some point.

Cheers,

BS

[James]

anyone try the 1900kv edf yet? i see it comes with the 1750.. just wondering as the 1900 90mm fan really woke up my stinger 90

Just flew it with this motor the other day...

[P51DPLT]

Just flew it with this motor the other day...

What motor, edf, esc combo do you have in yours James?

[GliderGuy]

GG,

This airplane has been around for a while.

What else would you suggest?
Cheers,

BS

Good job on your research! You might want to consider adding RF chokes for an added peace of mind. Cheap, easy to install, and can’t hurt.

Supporting evidence included Hugh ‘s confirmation of reduced frame loss and holds. My personal experience was a loss of control (twice) with an A-10 and once with the F-4…..no such instances since installing the chokes.

Search choke, RF choke, and ferrite for more details in threads for high-current ESC birds.

-GG

[Hugh Wiedman]

What motor, edf, esc combo do you have in yours James?

The upgraded F-4 MRC now sells comes with the 9 Blade 3672-1900Kv inrunner (6S version) with the same FW 130 amp ESC it's always had (same in all their 90mm 6S jets). Since you picked yours up from some previous owners, I'm sure it has the older 9 Blade 3748-1750 Kv outrunner. That's the fan I had for some time in both my F-4's, but just recently upgraded them both to the 12 blade 4068-1835 Kv inrunner, a real beast! It now flies incredible, IMO, especially compared to the old outrunner. Similar to the 8S version, but with slightly less flight time and a hair less speed. I'm currently getting 4 minutes on a 6000 mah battery with the 12 blade inrunners, but the speed and flight characteristics are far improved over the old outrunner you most likely have, so the upgrade isn't just about increased flight time.

Both of the 6S inrunners are drop in fits, and are fine on the stock FW 130 amp ESC. If you're flying off of grass, as I do, I would recommend the 12 blade inrunner. On the other hand, if you are on asphalt, or even just considering the price difference, the 9 blade inrunner is great as well. If you intend to fly this regularly, I definitely recommend you upgrade to one of the inrunners!

[P51DPLT]

The upgraded F-4 MRC now sells comes with the 9 Blade 3672-1900Kv inrunner (6S version) with the same FW 130 amp ESC it's always had (same in all their 90mm 6S jets). Since you picked yours up from some previous owners, I'm sure it has the older 9 Blade 3748-1750 Kv outrunner. That's the fan I had for some time in both my F-4's, but just recently upgraded them both to the 12 blade 4068-1835 Kv inrunner, a real beast! It now flies incredible, IMO, especially compared to the old outrunner. Similar to the 8S version, but with slightly less flight time and a hair less speed. I'm currently getting 4 minutes on a 6000 mah battery with the 12 blade inrunners, but the speed and flight characteristics are far improved over the old outrunner you most likely have, so the upgrade isn't just about increased flight time.

Both of the 6S inrunners are drop in fits, and are fine on the stock FW 130 amp ESC. If you're flying off of grass, as I do, I would recommend the 12 blade inrunner. On the other hand, if you are on asphalt, or even just considering the price difference, the 9 blade inrunner is great as well. If you intend to fly this regularly, I definitely recommend you upgrade to one of the inrunners!

Thanks for the info on the upgraded power systems. I will probably go with one of them, just need to get a few more flights on it before I go spending more $ on it.

Cheers,

BS

[locharrow]

Grabbed a quick flight this evening and practised long smooth banked turns .......went fine for the first, say half circuit, then the nose started to drop needing a wee bit rudder to lift it. Happened three time, carbon copies...screws up the smooth turn a bit. I'm already 15mm behind stock CG and don't want a repeat of the vertical lift off I had when the battery was further back although I know it would help keep the nose up. The plane will obviously lose some airspeed in a turn but it is still travelling at a fair lick ........... Is a rudder/ail mix the only answer?