Javad

Hello Guys,
I'm going to start a build thread for a F-4 Phantom, which was my dream jet since my childhood,

To start I've had some specification as: Not too big, not too small, with two turbine jet and not with a Y tail, & a target weight of max 17lbs (about 7.7kg) dry. So, I ended up with a 1/8 scale. Searching for a plan, I found a 1/72 scale plan with good detail on it & I scaled it up to 1/8, resulting 140cm wingspan and about 220cm long.

Attached are my scaled up formers to start:

JP-1

Javad,

This looks like an interesting project, looking forward to following this one, what are going to use for power, 2 X Xcoy 45s?
Alistair

Javad

Hello Alistair,

Yes, two Xicoy X45, if I achieve my target weight, if I end up much heavier, I would need to move up to two M70XBL,

Regards,

Javad,

Dave Wilshere

Javad

My prediction still stands 😉

Dave

Javad

Hello Dave,

I'll fight to achieve target , I just hope to escape from 2kg lead on nose :-)), otherwise your prediction would be correct for sure,

Any Lbs over 17, would be equal to a bottle of wine to your door, how many bottles are you expecting? ;-)) with an option to change wine to nougat

Javad,

grbaker

My Feedback: (29)

Weight might be attainable..
I wish I could remember what Tom Cook told me about the weight of his phantom with 2 turbax fans and K&B .45s. It was ridiculously low and It's similar in size. All of the ones I saw with Dynamax and OS .91s were in the high 20s. Mine is finally in the queue to finish, now that I have retired.

Javad

Hello Gary,

I did a search and I found below link about a "Tom Cook F-4". On first page it say all up weight 29 pounds ( I assume it is battery included) the size of plan also looks almost as same as my project:

https://www.rcgroups.com/forums/show...S-Tom-Cook-F-4

Compare to this example, I need to save 12 pounds to achieve my target weight

redtail

My Feedback: (15)

Sign Me Up - I Luv The F-4 So Much Chic

stuart_80

Looking forward to seeing this project Javad 👍

Stuart
PS - did you scale up from a Tamiya 1/72 kit ?

Javad

Thanks redtail and Stuart,

Not from a Tamiya, searching on google I found a plan form a guy named: "Jumpei Temm", so he send me copy of his 1/72 plan, then I printed in a large scale to achieve 1/8 scale,

kevinthoele

My Feedback: (1)

Gary

I did a Cook F4 with twin fans and it was high 20s ready to fly

Javad

Hello Kevin,

Do you mean 20 pounds? was cook F-4 1/8 scale? (about 220cm long)

Javad,

kevinthoele

My Feedback: (1)

Yes the JMP products F4 is 1/8 scale and yes 27-28 pounds was weight. I flew on Twin ducted fans and 120 single jet. So 20 pound twin turbines will fly it but not super fast. Keep the weight in the low 20's and it would be great. F4's are not the cleanest airplanes.

I have owned and flown almost all makes and models. Currently have 2 Skymasters. I have flown yellow, JMP. BVM, Feibao, Fly eagle, Century Jets to name a few. I wish you luck with your project!!!!!

Javad

I decided to have a one pice wing, and I went for a symmetrical airfoil NACA 0009;
Balsa sheet 1.5mm for wing, 25gram glass both side. Once sheets join together, I glassed one side dope, this side would go inside. Followed by outside glass applying G4;
Surface hinges, for both flaps and ailerons. No horns coming out of wing and servoes would be linked to horns already installed on flaps and ailerons using their own thickness

Javad

Many thanks Kevin,

Dave Wilshere

Javad

Great idea to use old magazines to distribute load over the sheeting....

JP-1

Javad,

Making good progress there,

Alistair

Javad

Hi Alistair,

I'm not quick builder, I am about 3-4 weeks ahead of thread, as I started the project about two months ago, I'll upload more photos to rich to present, :-))

Javad

Hi again,

One of our nice club members, encouraged me to work with "Fusion 360", so I learned basics to make sketch, so I was able to make former's files for Laser Cutting. However, laser cut formers are not in final shape, I would need too many cutting as I progress, you will see on photos,
As I have one pice wing, my turbine would in about tail, just where wing fishes,
To build up fuselage, I will start to make two section, will follow by rest of formers to join,

Javad

Hi again,

One of our nice club members, encouraged me to work with "Fusion 360", so I learned basics to make sketch, so I was able to make former's files for Laser Cutting. However, laser cut formers are not in final shape, I would need too many cutting as I progress, you will see on photos,
As I have one pice wing, my turbine would in about tail, just where wing fishes,
To build up fuselage, I will start to make two section, will follow by rest of formers to join,

kevinthoele

My Feedback: (1)

Great start!!! Enjoying your build.

Javad

Hello Kevin,

Thanks,

The time I have spent to think& search about how build up this puzzle is twice as I spend to cut& join balsa& lite ply :-))

Javad,

CARS II

My Feedback: (7)

Thank you for starting this thread, enjoying your build

Javad

Hello Guys,
As my plan is to have two turbine on back of the fuse, I have two choice to get the air to the turbines:
Option one: Not having any air duct, so from intakes air will go inside the fuselage and turbine will get the air; (too draggy for a not clean jet like F-4)
Opting two: add air duct and bring the air flow to turbines; (complex and adds weight)

I decided to make air duct, but the question was how?
After much thinking, I cut inside the formers in a way that I can create a duct air through the hols, while two side of the duct walls are balsa sheet & planking for fuselage and one side would be the wing itself. In other word, by this design, I only need to add one wall to create the duct, means adding only about 70 grams of a two pice of balsa sheet.
Please see the photos,
By running this two sheet of balsa, two main part of Fuse which have been mad before are connected now and fuse take shape :-))
Javad,
,

jcterrettaz

My Feedback: (1)

Very neat build, so precise ..following