Official Freewing 90mm F-4 Phantom II Thread

[janmb]

Freewing mechanically limits the turning radius on many models to minimize the risk of tipping them over after a landing when enough speed has not yet been scrubbed. It's common to see pilots trying to turn around too soon at too high a ground speed, resulting in scraped wingtips or worse.

To tighten the turning radius, move the clevis to the outermost hole on the steering servo. In models with a steering arm on the nose strut as well (instead of the captive sliding arm), move the clevis to the innermost hole. Experiment with your model and verify that the nose wheel doesn't bind in the retracted position. Two mixes may prove helpful:

1) A mix that cancels nose strut steering when the landing gear is retracted (this requires the steering servo to be in a separate rx port, however).
2) A mix that limits the steering throw as the throttle increases. i.e. on 0% throttle, the steering can move 100% of its range. At 30% throttle, the steering can move 60% of its range. Etc, etc. You'll need to experiment with your specific model (and runway surface) to find a balance between having the thrust to get moving, and having enough steering to matter.

Nose steering on a separate channel is almost a must in my book. While you *can* of course live without it, it provides SO many benefits - especially for lazy buggers like myself.

1. A trim mix on a knob, allowing me to fine tune straight tracking from the tx
2. Cutting the steering when retracted as you say
3. Tune nose steer sensitivity and rate separately from the throws and expo I want on my rudder
4. Instead of throttle (which sadly isn't really a good measure of speed anyway), I use my flap switch to toggle rates on my nose steering on some models. High rates when flaps up, low rates when half/full. This provides good control during takeoff and landing rollout, while you can pull up the flaps to make as tight turns as you like. Did this on the 104 and very happy with it there. Probably will do something similar on my A-10 and F-4 as well.

[fhhuber]

I also put nose wheel steering on a separate channel.

I just dial that channel to high expo, which gives tight turns available all the time when taxiing but you have to push the rudder stick pretty hard before its excessive for the takeoff run.

Once you get the nose wheel trimmed straight you practically never need to adjust its trim. I go back and adjust clevices to put all of my trims to center for take-off/landing speed.

Then I use the flight mode trims function to deal with the differences (usually a bit of elevator) for high speed, where I usually also have higher expo for the primary flight controls, but still 100% throw available.
I have had dual rates leave me wanting more throw when it wasn't available without flipping a switch. So I aim for always having 100% throw available and use dual ( or more, since DX-18 allows 5 flight modes) expo associated with aircraft configuration instead.

I never thought of disabling nose wheel steering with wheels up. The retract linkages typically are designed to put the nose wheel straight and make the push rod have no effect when the wheel is up.

[apmech1]

Im incorporating the freewing male setup on my 3dp ordinance from now on.

[seaviper]

Looking to maiden my F-4 this week. Power will be the FMS 12-blade unit. Has anyone flown this configuration yet?

[RickVB]

All of this discussion of separate channels and mixes would be great - if that was the question I posed. Actually, that has nothing to do with anything anyone asked here.

The question was, are there any great "Brandon" or "Steve" type ideas for improving the minimum turning radius? (Hint: separate channels and mixes won't help.)

[janmb]

I never thought of disabling nose wheel steering with wheels up. The retract linkages typically are designed to put the nose wheel straight and make the push rod have no effect when the wheel is up.

Yes, it isn't physically necessary, but still nice to save the servo and a little power.

[runway14left]

I love this plane and have 21 flights on her now. Wanted to share a little tidbit I've learned, although maybe obvious to some.

I tend to not use a lot of flaps. My full flaps is about what the manual says for half flaps.

The last couple days at the field I've been increasing the flaps and the landings are getting smoother and easier.

[janmb]

I love this plane and have 21 flights on her now. Wanted to share a little tidbit I've learned, although maybe obvious to some.

I tend to not use a lot of flaps. My full flaps is about what the manual says for half flaps.

The last couple days at the field I've been increasing the flaps and the landings are getting smoother and easier.

I prefer a lot of flaps on most models - most of all because it forces you into good habits regarding throttle use.

[RCjetdude]

All of this discussion of separate channels and mixes would be great - if that was the question I posed. Actually, that has nothing to do with anything anyone asked here.

The question was, are there any great "Brandon" or "Steve" type ideas for improving the minimum turning radius? (Hint: separate channels and mixes won't help.)

Rick, mechanically, other than replacing the servo arm with a standard arm and adding one of these style of connectors I don't know of another way to increase the throw to the steering arm.

[RCjetdude]

Got my cans painted last night.

[Shirty]

Nice!

[purduephigam]

Those are some hot cans! Hoping mine come in soon. Planning on some major airbrushing/weathering this weekend.

[fhhuber]

Putting the nose-wheel on its own channel lets you program for >100% servo travel. (without altering the rudder travel) Spekrum allows up to 120% and Futaba allows up to 150%. Futaba's 150% = Spectrum's 120% because Futaba's 100% is a smaller number of degrees than Spektrum's 100%.

There is also replacing with a programmable digital servo to get even more travel. Or use of a bellcrank to amplify the travel,but that can introduce a lot of linkage slop.

[seaviper]

My F-4 turns in about the same radius as the T-45. Don't stress over it. If you have it on a separate channel it WILL help. Then you can dial down the rudder without dialing down the nose wheel steering.

Other than that, replace the servo and servo arm.

[v8truckin]

I'll probably be ordering one of the chutes from a model rocket supply shop, posted earlier. What size did you wind up installing, Steve ? Not a lot of room back there, even with the new tail-piece.

couldnt find the link u spoke about of the rocket supply shop but...

When I did my chute mod to my FW su35 I used a shock chord and a rocket chute from this vendor. http://www.rocketchutes.com/ They are very well made chute, but are a bit thick as they are made of nomex. They have a 12” & 18” though neither of those sizes would be scale per RCjetdude , the 12” would allow u to squeeze the thicker chute in. Oh and they have lots of colors . Also the strings can b cut down to length if need be .

ill b using one of these chutes when my arrives

[RickVB]

Rick, mechanically, other than replacing the servo arm with a standard arm and adding one of these style of connectors I don't know of another way to increase the throw to the steering arm.

Thanks Steve, that's about all I came up with. You need to use a metal arm with those connectors to avoid slop from twisting the arm under load. Not so sure I'll be able to find one for that servo, which would mean changing the servo too, so it seems like more trouble than it's worth.

My F-4 turns in about the same radius as the T-45. Don't stress over it. If you have it on a separate channel it WILL help. Then you can dial down the rudder without dialing down the nose wheel steering.

Other than that, replace the servo and servo arm.

Not stressing over it, just find it an annoyance when I can't turn around from the centerline or I overshoot the last ramp to the taxiway be just a smidge and want to turn back hard. As I said, given the option, I probably will just live with it. Oh, and thanks for the heads-up; now I know I can expect the same thing from my T-45 which is next on the assembly line... :)

[JLambCWU]

More flying, flybys and a killer burner takeoff....Almost 70 flights on here and still solid!

[Aros]

Niiiiiiiice! Boy she's a beaut!

[seaviper]

Maidened mine today. Two flights so far.

Fms 90mm edf unit

flt 1...3:43, 3.77/cell, turnigy 5000 hd
flt 2...3:07, 3.85/cell, Admiral 5000


Right now i am at high rates, increased elev-flap mix a little, and cg is spot on no trim.

It's windy here and she doesn't care. She just floats in like a trainer

[seaviper]

Here is my heavy Turnigy placement. FMS fan unit.