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Feb 09, 2018, 09:23 PM
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Build Log

F-4D Phantom II 90mm EDF by Freewing


I managed to get the ARF-Plus version from Motion RC, just in time before the Friday morning stampede

http://sz-freewing.com/

https://www.motionrc.com/collections...phantom-ii-arf

https://www.motionrc.eu/collections/jets-and-ducted-fan

https://www.rc-castle.com/index.php?...th=470_507_508

http://www.rc-castle.com/index.php?r...+PNP&limit=100

http://www.f-hobby.com/rc-edf-jet-90mm-c-45_10

https://www.rcgroups.com/forums/show...Phantom&pp=100

Delivery if all goes well should be mid-April.

This thread in German : https://translate.google.com/transla...ing%26pp%3D100

The original F-4 D Phantom had a wingspan of 11.71m and an overall length of 17.76m, whereas the model has a ws of 103cm and a length of 155cm, so the overall scale is ~ 11.37 : 1 (based on wingspan) and ~ 11.46 to 1 based on the length.

https://en.wikipedia.org/wiki/McDonn...F-4_Phantom_II

The F-4 D comes with a new 90mm 9-blade plastic / metal fan w. outrunner, in some ways similar to the one in the A-10 (which is 80mm though). It seems like a light setup (but I have no idea how much that fan weighs - edit: 378g).

I will put either a WeMoTec Evo 90mm fan with HET inrunner motor in mine, or the equally acceptable lightweight JetFan 90mm.

Black or Brown, that is the Question


EDIT : Maiden video added March 24



Freewing F-4 Phantom JetFan 90mm maiden flights - combined video (3 min 21 sec)




F-4D Phantom II 90mm EDF by Freewing - Fourth Flight (3 min 8 sec)




Freewing F-4E Phantom Loops (3 min 8 sec)


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Freewing F-4 Phantom Landings (0 min 52 sec)


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F-4E Phantom II by Freewing - JetFan 90mm 4K (4 min 39 sec)


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Last edited by Herb; Oct 14, 2019 at 01:11 PM.
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Feb 09, 2018, 09:30 PM
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The Freewing F-4D is quite similar in size to the $99 beer cooler styrofoam FlyFly F-4 Phantom that has been around for years,

http://www.generalhobby.com/flyfly-p...ion-p-884.html

http://www.hobby88.com/shop/index.ph...sort=5a&page=1

https://www.rcgroups.com/forums/show...m-BUILD&pp=100

http://www.rc-network.de/forum/showt...on-jepe/page18

The latter is 104cm wingspan and 140cm length, so comparable to the FW F-4 (within one percent in wingspan).

At some point it was also sold (I think) as a fast foam by JePe :

http://www.jepejets.com/jepesite/Fas...f4/phantom.htm

The Fly Fly kit has a well known serious problem with the wing incidence, which some have (incorrectly) fixed by changing the thrust angle.

JePe recognized the problem and corrected it the right way, by changing slightly the wing incidence, by introducing a twist in the wing (see pics).

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Last edited by Herb; Feb 23, 2018 at 02:13 PM.
Feb 09, 2018, 09:39 PM
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... flew ok on 6S (I never had one) , esp. w/o landing gear :


F-4 Phantom von JePe (1 min 6 sec)


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F-4 Phantom II - JePe FastFoam (FlyFly) (5 min 8 sec)



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f 4 phantom jepe full flight (3 min 32 sec)
Last edited by Herb; Feb 16, 2018 at 01:17 PM.
Feb 09, 2018, 09:47 PM
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BVM makes a nice F-4, and so does Skymaster :

http://www.bvmjets.com/pages/kits/f-4.htm

http://www.skymasterjets.net/f4.htm

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Flies like a Phantom, no fly fly foam glider here ! :

RC F-4 Phantom - Florida Jets 2014 (4 min 31 sec)


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Huge turbine-powered F4 Phantom RC plane maiden flight (6 min 7 sec)
Last edited by Herb; Feb 16, 2018 at 01:24 PM.
Feb 10, 2018, 01:13 AM
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I got the Arf+ version, so will be providing my own power system .... Unlike the rather odd size 80mm, I have a few 90mm fans lying around.

6S is good up to ~2300 Watts, 8S will go easily to ~3100W.

I will try a 6S setup first. The esc will be as usual a YEP, a YGE clone : www.yge.de

WeMoTec 90mm fan info :

https://www.turbines-rc.com/en/141-e...r_class_mm_-90

JetFan 90mm info :

http://shop.ejets.at/OShop/ViewProdu...a&OShopLANG=en

HET 650/700 class inrunner motors :

http://www.highendrc.com/index_ecat.php?cPath=53_56

Freewing stock power is claimed to be 2200W on 6S and 3100W on 8S (see below).

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Last edited by Herb; Apr 13, 2018 at 12:08 PM.
Feb 10, 2018, 01:17 AM
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The Israeli IDF F-4 Phantom requires a complete repaint, and Callie graphics ...

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Feb 10, 2018, 01:20 AM
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The black Bunny VX-4 version requires major surface prep to give a smooth finish for the gloss black.

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Feb 10, 2018, 04:16 AM
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No clue why FW decided to make that plane. I think all manufacturers made one.
I have LX dual 70 - also similar size. Despite slats and brakes it's a hangar queen - fly it once a year to blow dust away.
What I don't like - it flies up/down like it should - as a draggy bomber. And left/right like mirage or J-10. Meaning you have to fight keeping it leveled, watch orientation and not do steep dives cause this thing needs space to turn.
Feb 10, 2018, 04:39 AM
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Quote:
Originally Posted by Herb
The original F-4 D Phantom had a wingspan of 11.71m and an overall length of 19.2m, whereas the model has a ws of 103cm and a length of 155cm, so the overall scale is ~ 11.37 : 1 (based on wingspan) and more like 12.39 to 1 based on the length.
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Hello Herb,

as far as I know the -D still had the short nose and therefore a length of 17,76m - the long nose (19,2m) with the gun came with the -E ? So the dimensions of the freewing F-4 correspond to the -D Version at a scale of 1:11,37 - right?

(this is why I did chooe the -E for my aerotetris-project )
Last edited by Mr. UD; Feb 10, 2018 at 04:45 AM.
Feb 10, 2018, 02:25 PM
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Nice !

The Israeli F-4 version I am thinking of uses three or four specific paints shown below.

https://en.wikipedia.org/wiki/McDonn...erators#Israel

These could be custom mixed (I don't like using heavy as f&%$k home depot paints) or most likely I will find a close match of Tamiya acrylics (readily available as opposed to Gunze), for which I might just have to do one or two custom mixes only.

The first one below calls for Tan FS 30219, Sand FS 33531 and Green FS 34227 for the top, and Pale Blue FS 35622 for the underside.

F-4D vs. F-4E variations :

http://aviation.watergeek.eu/f4c-panel.html

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Last edited by Herb; Jun 21, 2018 at 05:27 PM.
Feb 10, 2018, 02:47 PM
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Most likely I will first fly it with my standard 6S 90mm setup (in the WeMoTec or JetFan variety) with a YEP 150esc, which should pull around ~ 2100 Watts on good 5000mAh batteries.

That should show clearly if 6S is adequate or not, I suspect not (for me ).

The issue is :

* How good is the ducting ?

* How many foam steps and foam bumps have been left in there ?

* How much performance gets lost by blowing hot air straight on that bifurcated outlet (Hosenrohr) ?

* Is the bifurcated outlet shaped correctly, ie does it have a sharp (as opposed to rounded horror) leading edge ?

* How thick are the wings?

* How draggy is the airframe as a whole ? etc etc


The next setup then would be 8S or 9S.

For 8S one has 8S = 4S + 4S - but I hate having to buy new batteries specifically for this plane !

For 9S I do 9S = 3S + 3S + 3S, which works out much better since then I can fly any 6S jet on 6S = 3S + 3S

Any higher S of course makes no sense in such a small airframe ...

Edit: From the picture below, it seems like the overall shape of the bifurcated outlet is done well, it starts to diverge right at the fan tail end (or more appropriately at the end of the motor fairing). In general a streamlined motor fairing would improve things further, but possibly reduce motor cooling.

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Last edited by Herb; Feb 16, 2018 at 08:32 PM.
Feb 11, 2018, 01:43 AM
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The full flying (FF) elevator is shown in the picture below, mine might get a stronger more rigid linkage.

Either via a carbon rod, or an entirely new steel & brass rod.

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Last edited by Herb; Feb 16, 2018 at 08:33 PM.
Feb 12, 2018, 01:54 PM
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The stock F-4 includes a new 9-blade 90mm fan with an outrunner motor (see pic below) which weighs 378 grams.

It is claimed somewhere that the new stock unit pulls ~2200W on decent 6S batteries, but I could find no useful info on it anywhere...

Freewing also offers an "upgraded" 8S version which includes a 536g 12-bl metal fan with inrunner, and an 8S capable esc:

https://www.motionrc.com/products/fr...phantom-ii-pnp

It is claimed that the "upgrade setup" delivers ~ 3100W at ~105A on 8S.

The latter ESC will not run more than 8S, at least according to the specs ... This HW one ($130) seems rated for 5-8S, that has to do with the MosFet ratings I guess.

https://www.motionrc.com/pages/searc...oduct_type=ESC

https://www.motionrc.com/products/fr...-brushless-esc

Hobbywing does make one though that is rated for 12S :

http://www.hobbywing.com/category.ph...er_attr=6345.0

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Last edited by Herb; Mar 04, 2019 at 03:07 PM.
Feb 13, 2018, 02:24 AM
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From one of the Freewing pictures posted earlier each outlet is apparently ~ 52mm in diameter which makes it around 85% FSA for a 90mm fan - which is just right

The ducting has certainly improved quite a bit over older FW models with those cavernous cheesegraters . Finally the cheesegrater is gone, at perhaps no visible loss in performance.

It is good that Freewing finally realizes that even in the foam world decent ducting and simple aerodynamics will allow you to fly better, faster and longer with the same power ...

So here the twin outlet diameter @52 mm on the F-4 has been computed correctly

58mm is 82.0mm single fan equiv. and 106.4 % FSA
53mm is 79.5mm single fan equiv. and 88.9 % FSA
52mm is 73.5mm single fan equiv. and 85.6 % FSA
51mm is 72.1mm single fan equiv. and 82.3 % FSA
50mm is 70.7mm single fan equiv. and 79.1 % FSA

https://www.rcgroups.com/forums/show...8&postcount=69

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Last edited by Herb; Jul 27, 2018 at 06:27 PM.
Feb 14, 2018, 01:24 PM
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Below a leftover Freewing 90mm edf stock metal fan from the 90mm Freewing F-16, gathering dust for now ... that one now has a JetFan 90 in it and flies a lot better

Next to it an even older Freewing 90mm plastic fan with WeMoTec rotor copy from their G-91, never even tried to fly anything with it (low power ~1500W).

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Last edited by Herb; Mar 20, 2018 at 01:35 PM.


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