Official Freewing 90mm F-4 Phantom II Thread

[thisguy65]

Is it possible to get 4-5 minute flight with this F4 in stock configuration?

Eflite F4 goes together easy as pie. With As3x I think it's very important to not touch the sticks after a trim adjustment...I think.

[icepirate3]

What trim issues?

Tendency to wave the wings at speed and drop a wing into a spin with no warning at stall?
One that I have seen on several aircraft and often turns out to be a minor misalignment of aileron neutral. Just one turn of a 2-56 clevis pushing both ailerons down can give a plane some very nasty habits but you have a hard time measuring that the ailerons are not really straight.

A small off-angle of the nozzles can also cause major issues. The issues will vary with power setting.

That got me thinking about my trim issue. I have quite a bit of aileron sub-trim to the right to maintain level flight with both ailerons neutral and equal. Have checked the lateral CG and the vertical fin is straight. Flaps are also equal so it's been bugging me for a while. I never thought to look at my nozzles. They are the 3DPUP and i'm pretty sure I put them on lined up but I could be wrong. I will look at it this weekend.

[Evan D]

The Freewing is my favorite EDF. It flies awesome whether fast or slow. Mine doesn't pitch up on throttle. At least not noticeably

and that's on 8S. I think some of this may be people balancing nose heavy which needs up trim to fly and then the faster you go the more the up trim has effect and you climb.

This guy, look at Hobby Star batteries at RCjuice.com or Roaring Top at RCjetwerx.

Looking at freewing videos now. Could spend little more coin and upgrade the ESC/EDF and get longer flight times? Wonder how the 6000 Pro that just came out would work.

[Evan D]

Edit, the 500g are 5000mAh. The 574g 6000's. I am able to balance okay with 1000g packs. I did cut the foam at the rear of my battery area and moved the ply plate back to get a more rearward balance (you've seen my pictures of the cut). I'm now using 8S Hobby Star 5200 at 865g Pushed almost as far back for a even more rearward balance point.

Cut the foam...

I tried putting two of the new Admiral 4S 6000 Pros in my F-4E which has a JP 8S fan in it and I can't get the batteries back far enough to get it to CG without modifications. As it is I just flew it on my normal Roaring Top 6S/2S 5000 70C packs until I can decide how I want to get the 6000's to fit. I don't have any trouble seeing either the gray or camo versions personally. I flew an E-Flite Viper recently and noticed issues keeping it in trim but have not flown the new F-4. I did get to watch one get assembled which was a snap and it appears to be a nice bird.

[thisguy65]

The Freewing is my favorite EDF. It flies awesome whether fast or slow. Mine doesn't pitch up on throttle. At least not noticeably

and that's on 8S. I think some of this may be people balancing nose heavy which needs up trim to fly and then the faster you go the more the up trim has effect and you climb.

This guy, look at Hobby Star batteries at RCjuice.com or Roaring Top at RCjetwerx.

Evan, Thanks! Where do you typically CG at?

I use Roaring tops for my Viper, F-16 and Eflite F4. I do love their batteries. Been wanting for RCJuice to get some 4200 45c in, he did early march but we were at the hospital prepping for our first child o be born.

[Evan D]

To be honest I'm not sure where it's balanced now. I balanced it a bit more rearward when I first built it based on others that found the book CG was nose heavy. But I've moved it further back a couple times since then. I can't go any further back as it will pitch up dramatically on take off if I do.

Evan, Thanks! Where do you typically CG at?

I use Roaring tops for my Viper, F-16 and Eflite F4. I do love their batteries. Been wanting for RCJuice to get some 4200 45c in, he did early march but we were at the hospital prepping for our first child o be born.

[Bobaroo]

Is this profile kinda hard to see? Debating between the camo and ghost grey.

https://www.hobbysquawk.com/forum/rc...l-thread/page7
​​​​​​Post #129 for Discussion on Orientation

​https://www.rcgroups.com/forums/show...€‹â€‹â€‹â€‹â€‹
Dec 2018 Discussion on NozzleMod

[Elbee]

Got the nozzles finished and like the look. Best, LB
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[EA-6B Geek]

That's gonna be one salty Phantom LB. Looking great.:Cool:

[barron06]

We have 4 F-4s (in our club of 5) and 3 have had the elevator servo die without warning. The other F4 has not been built yet. All are first batch runs. Over the years, I've had to ground 4-5 other birds while in the field with them due to what I call "good" failures. This is the only 1 I've lost due to a "bad" failure. Due to the massive damage, I could not say it was a bad servo 100% but given the history of the F4 elevator servo at our field, I would bet a dollar on pennies.

I'm beginning to think it may combination of things causing these servos to die in the F4:
- The amount of flight loads imposed on it (or any F-4). This had been mentioned before. Indeed, I can imagine some are flying with a forward cg, which does not help.
- The power of the servo itself. It seems a 30gm / 60oz/in servo should be adequate but maybe not when you consider the speed this thing is moving at.
- When relating to the above, consider how this servo is mounted. It sits in a bed of foam, which it a great heat retainer. Only the top is exposed, and it's facing upside down. Also, everything is in an enclosure, out of the windstream. My buddy in the video reported that his servo smelled burnt when he disassembled it.

We are both going to replace our servos with Hitecs and adding some sort of cooling to this area. Other than us getting a bad run of these servos, I don't think it's the servo design itself but I cannot help but consider the environment they operate in. We fly our F4s with maybe 5-15 cool down minutes between flights, so this may be an untested senario by the MRC/FW team. We flew them through the summer with no problems though. In 2 out 3 of our failures, we were on our 3rd-4th flight of the day.

Concerning servos, there are good failures and bad failures. A servo that has been jittery or moving irradically (during pre-flight checks) then dies is a good failure. No one should ever lose a bird this way.
The bad failures are the ones that die suddenly, without any warning. This cost me my 1st F-4 due to the elevator servo (~86 flights). Because of the "loss of pitch control" this bird can get into, I was especially careful to check it every flight. Not just a stick bang but a slow movement to detect any unusual movement.

https://youtu.be/Ik7SDovkaD8

[Evan D]

Have you opened up the tail and looked at the servo and linkage?

[barron06]

Linkage is good.

[TMoyer]

Got the nozzles finished and like the look. Best, LB
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Wow, those look really good!

[Elbee]

Hey Y'all, I know there is/was a 'location notch' for the OEM Plastic Nozzle, but when I removed those, the notch came out with those. My question is where is the 'notch' suppose to be? :Thinking: For example, looking forward from the tail section, RH-12:00, 11:00, ??:00 and LH-12:00 1:00, ??:00. Thanks in advance. Best, LB

[TMoyer]

Looking at the back of the plane forward, mine were at approximately 1 o’clock for aircraft left and 11 o’clock for aircraft right. If you put them on at those positions and then swivel them a bit you can find the sweet spot where they like to sit.

[Elbee]

Looking at the back of the plane forward, mine were at approximately 1 o’clock for aircraft left and 11 o’clock for aircraft right. If you put them on at those positions and then swivel them a bit you can find the sweet spot where they like to sit.

TM, Thank You, Sir. Best LB

[e4dragongunner]

This is what I did !

[Hugh Wiedman]

Finally finished putting my 4 coats of Gloss exterior Spar Urethane on about 8 of my planes, including my 2 F-4's. The quality of the foam is so good, it's hard to tell it from wood/monokote except up close. Oddly enough, the CG was not affected on the camo F-4, but the Blue Angel needed about an ounce and a half in the nose to bring it back to 140mm with the battery in the same location-go figure-just glad I checked the CG before and after coating.:Thinking::f4phantom

[Elbee]

This is what I did.

E4DG, I am right at this point in my build and will duplicate your work. Thanks for the tip and the pics. Best, LB

[Bobaroo]

Finally finished putting my 4 coats of Gloss exterior Spar Urethane on about 8 of my planes, including my 2 F-4's. The quality of the foam is so good, it's hard to tell it from wood/monokote except up close. Oddly enough, the CG was not affected on the camo F-4, but the Blue Angel needed about an ounce and a half in the nose to bring it back to 140mm with the battery in the same location-go figure-just glad I checked the CG before and after coating.:Thinking::f4phantom

These are Very Unusual findings indeed. Assuming the same technique and volume of product were applied to two identical objects, one would expect nearly identical mass transfer and cg shift from both of them.

Are you flying this at a cg of 140mm ? Can I ask, where your Neutral FFStab is indexing with that cg. Reason being, I've been flying at 195mm and have a great looking FFStab Indexing going on back there for my 195mm !! Believe me, I am not trying to initiate a Full-On Raging cg Jihad here !! Just looking to see a Flyable/Working Stab indexing at that 140mm cg. Thanks !