Official Freewing 90mm F-4 Phantom II Thread

[Hugh Wiedman]

Got my 8s F4 up this weekend, what a blast. My buddy Jake was taking some great pics.

Outstanding looking F-4! I have 2 of them, both 6S that flew OK for the last couple years, but when I recently upgraded the fan on both to the 12 blade 1835 Kv inrunner, I found that it completely transformed the way it flew. A buddy has the 8S and we now fly together and mine flies and sounds identical to his, the only difference is he gets a bit more flight time than the 4 minutes I'm getting. Should have gotten the 8S to begin with, but since I didn't, the 12 blade 6S is the next best thing (as long as you got $160 to blow). The 9 blade 6S it comes with now doesn't quite compare to the 12 blade either, but it is better than the 9 blade 1750Kv outrunner both of mine came with when I got them. Have to say it's now definitely been elevated to "first string" status.

[T- Elbert]

Hugh
i have 2 of the original F-4’s and they fly very nice but yes the 8 s is quite a upgrade. If your a grass ops guy it’s the only way to go.

[Hugh Wiedman]

Hugh
i have 2 of the original F-4’s and they fly very nice but yes the 8 s is quite a upgrade. If your a grass ops guy it’s the only way to go.

I am a grass ops guy and no doubt the 8S is a huge upgrade. But I have to say the 6S 12 blade inrunner is a pretty big upgrade itself from the original fans as well (still short of the 8S, but still 100% better). I get off the grass now in less than 100 feet and have what seems to be unlimited vertical (maybe just seems that way considering how it started). When I first took off with the new fan, I was shocked and almost not ready for it to get up so quickly. The old birds used to "groan" at the top of a Cuban 8 or split S, but now I don't even need full throttle to get there (but it's nice to have it in the back pocket if need be). A wing stall was an occasional issue to watch for on some maneuvers, but no longer. I'm not a speed demon interested in high speed passes and other then on take-off or going vertical, I'm rarely at 80-100% throttle, so I thought when I first bought the F-4, "I don't need 8S, that's for speed jockeys". But how wrong I was, as Mr. LB like's to say, "Ain't No Substitute for Horsepower".

[locharrow]

"Got my 8s F4 up this weekend, what a blast. My buddy Jake was taking some great pics"

Great atmospheric pics T...the grey scale F4 is brilliantly poised.

[GliderGuy]

Good job locharrow!

FYI - There was a discussion on the MiG-29 thread about battery management and an almost crash.

Here’s a slick little visual “helper”...

Tiny, too. 2cmx1cmx0.2cm

Link follows....ordered some!

https://www.amazon.com/dp/B06Y6JM98R...V0PQ7GJVGJAB39

[Evan D]

Odd it says different size further down in the description.

Dimensions: 25x12x3mm
Weight: 0.3g

[GliderGuy]

Odd it says different size further down in the description.

Dimensions: 25x12x3mm
Weight: 0.3g

mm vs cm....pretty close once this is taken into account
-GG

[50 Fly]

Know this is outside the bell curve, but those who are flying the F-4 with turbines, you might be interested.... I found out the core issue for why the model was not rolling well when vertical (10 pounds of thrust allows one to spend some time going straight up!) The solution had nothing to do with CG, aileron differential or any aileron-rudder mixing - tried them all. The issue was the thrust angle. Problem was, the Phantom had a "corkscrew" look to rolls when going straight up. Horizontal slow rolls didn't seem as bad. So I discovered the core issue by flying straight and level, near full throttle, pulling to vertical with the throttle pulled back, and rolling with no throttle. The roll was perfect!. Once I knew it was a thrust angle issue, it was simply a matter of experimentation - made some 2 degree thrust wedges. First attempt was to remove some down thrust, it was worse. So I flipped the wedges around and "voila'" the airplane rolled nearly axially. It's a lot more down thrust than I'd have ever guessed, but the model also tracks better horizontally when going from slow-to-fast. Takeoffs are a bit different now too. Experimentation is good. My thanks to Keith Alexander, who put me on to the no-throttle vertical roll test.

[davegee]

Hi All: I'm getting my new Freewing F-4 put together, and am confused on how to set the stabilizer with relationship to adding nose up trim with the flaps out.

So, here are my questions.

1) The manual says:
"Before flying, adjust the elevator's center position to the right photo." It shows moving the elevator (stabilizer) 8 mm down from the seam where you screw on the bottom part cover of the fuselage. Question: Is this position with a flaps up takeoff, or a takeoff flap position (25mm down flap as I plan to do.)?? In other words, I started with the elevator level with that seam. I then mixed the elevator/flap so that at takeoff flaps (25mm flap down position) the elevator is moved down 8mm. Is that correct?

2) With flaps up, should the elevator in concept be at the seam between the fuselage and that cover piece that is screwed onto the top fuselage piece?

Thanks for any help on this!!

Regards,

Davegee

[GliderGuy]

Hi Davegee.....

Pretty critical / need to get it CORRECT.

With flaps up (no flaps)...adjust per the photo below. Then to the left of the photo the manual says....(and I am adding text for clarity)
FULL FLAPS AND HIGH RATE 5 mm more nose up elevator (this means the front edge will now be 13 mm below the seam)
FULL FLAPS AND LOW RATE 3.5 mm more nose up elevator (this means the front edge will now be 11.5 mm below the seam)

Don’t overdo the mix!!! Make sure everything is the same on both sides.

Basically, the bird pitches nose down when the flaps are lowered....so the mix counters this.

If you have your CG aft of the manual recommendation, reduce the above amounts a little.

-GG


Photo of trim setting....Flaps up
Transmitter elevator trim slows “0” or neutral and the elevator stick is in the middle....no stick pressure applied.

[Hugh Wiedman]

Hi All: I'm getting my new Freewing F-4 put together, and am confused on how to set the stabilizer with relationship to adding nose up trim with the flaps out.

So, here are my questions.

1) The manual says:
"Before flying, adjust the elevator's center position to the right photo." It shows moving the elevator (stabilizer) 8 mm down from the seam where you screw on the bottom part cover of the fuselage. Question: Is this position with a flaps up takeoff, or a takeoff flap position (25mm down flap as I plan to do.)?? In other words, I started with the elevator level with that seam. I then mixed the elevator/flap so that at takeoff flaps (25mm flap down position) the elevator is moved down 8mm. Is that correct?

2) With flaps up, should the elevator in concept be at the seam between the fuselage and that cover piece that is screwed onto the top fuselage piece?

Thanks for any help on this!!

Regards,

Davegee

Follow what GliderGuy has posted. One additional recommendation, set your TX up with Flight Modes tied to the flap switch, then go to Trim Setup and set elevator to FM (Common Digital is default). This will allow you to further adjust the elevator for each flap position while in the air and it keeps that trim setting so after that whenever you change flaps, the trim is exactly what you like. Much better than guessing and taking it up, then adjusting again on the ground and over and over. I also set ailerons in the Trim Setup menu to FM, just in case each of my flaps do not extend the exact amount. This is a top 5 TX programming issue for me with any aircraft with flaps. If you're not familiar with this, just let me know and I can give you a more detailed explanation. It takes about 30 seconds to set this up and once you do, you'll include that ability on every aircraft you have with flaps.

[locharrow]

Coupled to 50Guy's post and the latter posts concerning the required up trim for level flight, if the throttle is cut at full speed to remove the jet "pitch down", assumed to cause barreling in a vertical roll, would that not let the positively trimmed stab take over the pitch control and CAUSE barrelling in a vertical roll? I have two sprogs with aero/naut degrees and NEITHER has an answer to this...... Still waiting on new glasses before I take the F4 up again!!

[davegee]

Hi Davegee.....

Pretty critical / need to get it CORRECT.

With flaps up (no flaps)...adjust per the photo below. Then to the left of the photo the manual says....(and I am adding text for clarity)
FULL FLAPS AND HIGH RATE 5 mm more nose up elevator (this means the front edge will now be 13 mm below the seam)
FULL FLAPS AND LOW RATE 3.5 mm more nose up elevator (this means the front edge will now be 11.5 mm below the seam)

Don’t overdo the mix!!! Make sure everything is the same on both sides.

Basically, the bird pitches nose down when the flaps are lowered....so the mix counters this.

If you have your CG aft of the manual recommendation, reduce the above amounts a little.

-GG


Photo of trim setting....Flaps up
Transmitter elevator trim slows “0” or neutral and the elevator stick is in the middle....no stick pressure applied.

Hi Glider Guy: thanks for the input. So here's where I am right now. I have the stab trim set with the flaps up to the neutral stab position of 8mm down (pitch up trim) from the fuselage seam. My friend set up Flight Modes on my previous F-4 that is now retired, but I don't know anything about them and would probably screw it up if I tried.

So, I have LOW rates and HIGH rates set up close to what the manual says to do.

I very seldom switch from LOW rates to HIGH rates, LOW rates work for all the planes that I fly the way I do especially, for the maiden.

I'd like to use a takeoff flap position for takeoff, approximately 25mm flap down from neutral. I use a takeoff flap setting on all my jets and retract them after the gear is up and accelerating.

For landings, I would like to use 45mm flap down from neutral, or flaps up position, per the manual.

So, if I am just going to stay in LOW rates for now, and want to use that takeoff flap setting I was talking about, how much stab trim down (pitch up trim) position should I set for that in mm? You mentioned in your reply to my question that with LOW rates and FULL FLAPS, I should have the leading edge of the stab to be a total of 11.5mm below the seam, if I understood you correctly.

Appreciate any comments on this, something to get me close when I do the maiden. I hope that makes some sort of sense, I'm rather confused with this at the moment. Just don't want to takeoff with an out of whack stab position and have problems just trying to fly it safely to the ground again! I'll be totally alone doing this.

My CG and everything else is pretty much set to the manual recommendations. Everything is getting closer to the maiden time, once I am comfortable with these stab settings versus flap settings.

Thanks!

Davegee

[davegee]

Follow what GliderGuy has posted. One additional recommendation, set your TX up with Flight Modes tied to the flap switch, then go to Trim Setup and set elevator to FM (Common Digital is default). This will allow you to further adjust the elevator for each flap position while in the air and it keeps that trim setting so after that whenever you change flaps, the trim is exactly what you like. Much better than guessing and taking it up, then adjusting again on the ground and over and over. I also set ailerons in the Trim Setup menu to FM, just in case each of my flaps do not extend the exact amount. This is a top 5 TX programming issue for me with any aircraft with flaps. If you're not familiar with this, just let me know and I can give you a more detailed explanation. It takes about 30 seconds to set this up and once you do, you'll include that ability on every aircraft you have with flaps.

Hi Hugh Wiedman: I have a Spektrum DX 18. My friend set the plane up in flight modes through the flap switch, I believe. But I don't know much more about Flight Modes than that.

If you could do me a favor and give me a step by step process as to how to set up the radio for Flight Modes so that I can trim in the air for flaps up, flaps takeoff, and flaps landing, that would be much appreciated. I can play with it and see if I got it down correctly.

Per Glider Guy, he gave me some good tips. I think my stab trim position setting was WAY out of whack and would have been a problem had I tried to fly it that way. For now, when the flaps are up, the stab leading edge shows 8mm down from the fuselage seam. For takeoff flaps, about 25mm down wing flap setting, stab is about 10mm down from the fuselage seam, and for full flaps, about 45mm flap down, the stab position is about 11.5mm down from the fuselage seam. I'm hoping that that is at least in the ballpark now, subject to tweaking it some before maiden next week.

[GliderGuy]

Hi Hugh...Please assist with any further set-ups he needs. You are more familiar with FM xmitter programming.

Davegee - On the maiden, I STRONGLY suggest NO FLAPS on take-off. Then play with your flaps up high on the maiden. If things are not good and she behaves badly (pitches up or down with flaps down)...then land without flaps. The bird will do fine with no flaps.

The F-4 is a ground hugger even with flaps down on take-off. You must pull her off with some back stick once her speed is up.

Glad the added explanation helped....pretty sure your initial set-up would not have ended well.

-GG

[Hugh Wiedman]

Hi Hugh Wiedman: I have a Spektrum DX 18. My friend set the plane up in flight modes through the flap switch, I believe. But I don't know much more about Flight Modes than that.

If you could do me a favor and give me a step by step process as to how to set up the radio for Flight Modes so that I can trim in the air for flaps up, flaps takeoff, and flaps landing, that would be much appreciated. I can play with it and see if I got it down correctly.

Per Glider Guy, he gave me some good tips. I think my stab trim position setting was WAY out of whack and would have been a problem had I tried to fly it that way. For now, when the flaps are up, the stab leading edge shows 8mm down from the fuselage seam. For takeoff flaps, about 25mm down wing flap setting, stab is about 10mm down from the fuselage seam, and for full flaps, about 45mm flap down, the stab position is about 11.5mm down from the fuselage seam. I'm hoping that that is at least in the ballpark now, subject to tweaking it some before maiden next week.

As per GG's suggestion, if you are taking off of an asphalt runway, you don't really need take-off flaps on the maiden. On the other hand, if you are flying off of grass, as I usually do, take-off flaps will certainly help. Additionally, on grass, you'll want to start your take off run with at least 60% or more up elevator so it helps relieve any down pressure on the front nose wheels that will slow down your take-off run. Once you get up some speed, release that up elevator pressure back to almost only 5% up elevator so you get a smooth take-off pitch. If you don't relax that up pressure soon enough, the jet will jump off the grass all at once and you'll be in a VERY nose high climb.

Back to Flight Modes. All this does is allow you to trim any surface selectively based upon whatever position the selected flight mode switch is set, in this case the Flap Switch. So for this, you assign the flight modes in your TX to your flap switch. Without flight modes, the trim you put in stays the same in all situations. With FM's once you change a switch position, you also change the trim in that configuration. When you trim an elevator (of any surface) without flight modes, that trim stays in each position you select for flaps and you have to guess how much elevator compensation to use in the Flap System settings. So this is what you need to do:

I know yours is already set with Flight Modes, but you should know how to do it for other models and exactly what it does for you.

1) First set up the flap system with compensation on the elevators as suggest above-this is only a "best guess" but hopefully will be close, but definitely not perfect.
2) Go to the 2nd set of menus (use the scroller and go down to "System Setup", select, confirm yes, then the 2nd group of menus come up) and go down to F-Mode Setup and select
3) Go to Switch 1: which says inhibit scroll to that and select, then scroll till you can select your flap switch (in my case it's Switch D). You can also set it for additional other switches as well, like gear switch, rate switch, etc. but for this Switch 1 is sufficient
4) Back out of that menu and go down one menu to "Spoken Flight Mode" Across from Speak: you can tell it what to say when you change that switch, like F Mode 1 (or 2 or 3) and test it out. You can also have it say Flaps Up, or Take-off Flaps or Landing Flaps
5) Back out of that when finished and go down 2 menus to Trim Setup and select
6) This shows a list of surfaces starting with Throttle/Aileron/Elevator/Rudder/etc. and next to each the default would be Common Digital for throttle and just Common for everything else. Go down to elevator and go across and change it to F Mode. As I said, I also do Aileron, just in case my flaps do not deflect at the exact same distance, which may cause a slight roll.

Now your done setting it up, should take about 30 seconds.

The only difference now is you are able to trim the elevator (and aileron) in each position of the flaps and it remains. You can check it out by putting the flaps up, trim a couple clicks on it so it shows say +6, then go to take-off flaps and the elevator trim is now 0, as is the landing flap position. I have to say of my 15 or so aircraft with flaps, none of them have the exact same trim in all 3 flap positions (even though I started with best guess compensations in the flap system settings).

On the maiden, once in the air, trim all your surfaces with the flap ups first. Then, I suggest you go to maybe 60-70% throttle, switch to take-off flaps, and "re-trim" the elevator (and aileron if you selected FM for that as well). Then I suggest you go to landing flaps while still at 70% throttle (keep the airspeed in case of something wonky happening), and trim the elevator, then slow it down to maybe 40-45% throttle (which will be your landing approach throttle) and fine tune the elevator trim. From this point on, the jet won't pitch up or down whenever you change flap positions. Additionally, I always find myself occasionally changing the trims depending on if I'm playing around with CG, or there is a change in weather conditions so FM's help greatly.

I learned this several years ago when one of our "expert" turbine jet pilots flew one of my planes. The very first question he asked about my TX was "do you have Flight Modes set up with your Flaps". When I responded with a stupid look on my face, he started programming my TX and after 30 seconds proclaimed "Well you Got them Now". My response was "What the Hell did you just Do and show me How to Do that Myself". Since then, it has been maybe the single most useful tool, IMO anyway, and I never leave home without it. I've let a lot of other great pilots fly my planes and every one of them has asked that question about my TX setup before they fly. You will never guess exactly what compensation to put in the flap system settings, but this allows you to get it flying perfect after maybe 1-2 minutes of the maiden. I've seen guys without it, they trim for level flight, deploy flaps, have to trim it for that, then raise flaps, retrim, then try to land, have a fire drill, retrim again, land and then forget what trim worked for each setting.

The elevator comps you get from any of us and from the menu are dependent on just how much deflection we use, the speed of the aircraft we use it at, and most likely the CG we like to balance at. So whatever you use, it won't be exactly what you want. FM's allows you to get it perfect on the maiden and doing it only once, but still allows you to fine tune it later. To give you an example, the elevator trim I have on my Corsair (and I started with a recommended compensation in the flap settings), ended up at +10 flaps up, -2 take-off flaps, and +44 on landing flaps, but found I like 55 degree landing flap deployment which acts like an "air brake".

If you need any additional help, you can always PM me so everyone else in this thread doesn't get overly bored.

[locharrow]

"Per Glider Guy, he gave me some good tips." .....Dave he missed out a couple..................Wear loose underpants allowing for pucker factor and ask forgiveness for all your sins! I was lucky, I maidened accidentally on a high speed taxi test! Good luck, it's all worth it !!

[davegee]

"Per Glider Guy, he gave me some good tips." .....Dave he missed out a couple..................Wear loose underpants allowing for pucker factor and ask forgiveness for all your sins! I was lucky, I maidened accidentally on a high speed taxi test! Good luck, it's all worth it !!

Good one, locharrow!! I used to have the SEO painted version for a couple of years, flew it a ton. But that has been 18 months since I retired it. A maiden is always full of promise and potential heartbreak. I'll stock up on some loose underpants at the local Walmart up here in distant northwest Wyoming! Glad your maiden went well!

[GliderGuy]

Great advice locharrow! Thanks Hugh. I copied your post...saving for when I upgrade to a higher end xmitter.

One additional tip Dave...Of the 3 I have flown, every one had a wing roll left on the maiden. Took about 3-4 clicks of right aileron trim. You may wish to preset your trim and avoid the SURPRISE. See photo..

MRC customer service guy says he did the same on his.

-GG

[davegee]

Hi Hugh...Please assist with any further set-ups he needs. You are more familiar with FM xmitter programming.

Davegee - On the maiden, I STRONGLY suggest NO FLAPS on take-off. Then play with your flaps up high on the maiden. If things are not good and she behaves badly (pitches up or down with flaps down)...then land without flaps. The bird will do fine with no flaps.

The F-4 is a ground hugger even with flaps down on take-off. You must pull her off with some back stick once her speed is up.

Glad the added explanation helped....pretty sure your initial set-up would not have ended well.

-GG

Hi Hugh: Thanks for the in-depth response! A lot to chew through and I'll start digesting it. I would like to have the FM fully operational for the maiden and subsequent test flights. Hopefully I can go through your instructions and make it happen. I can PM you on this subject for future questions I might have on setting it up.

The field that I fly from is asphalt, about maybe 35 feet wide and around 600 feet long. It is pretty bumpy in spots where it has been repatched over the years. I take yours and GliderGuy's point about doing the initial maiden flight with the flaps up. The field elevation here is 5,000 MSL. Would probably do the maiden early while the temps are cooler. Do you think the high field elevation for this plane would be anything to worry about doing a flaps up takeoff? It would sure simplify the first takeoff until I could get it up into the air to test out the flaps. And I would use the full length of the runway, too.

Glider Guy, thanks for all the tips, and I hope to report back a successful maiden on my plane in about a week or less!

davegee