F-4 Phantom - Twin 70mm EDF Monster!!

Muquacksa

Member
I was thinking, would it be possible to make the f-4 phantom compatible with twin 90mm 10 blade edf units? I have 2 available to me and I think it would look and feel pretty nice on such a beutiful rc jet like this. If it is possible, how could I do it?
 

AkimboGlueGuns

Biplane Guy
Mentor
Quick and dirty way is to just scale the plans up by a percentage to match the fan size. You can likely get 90mm fans into the plane at original scale just by scratch building new fan mounts. Best answer is a mix between the 2. Size up the plans just a bit, and make proportionally larger fan mounts for an increase in performance without really changing wing loading.
 

Muquacksa

Member
Thank you!
I actually recoeved that a day or 2 ago and still going through it to understand the general building process!
And just to make sure scince I definately will use a 90mm onn the Diamond if possible, this process would work? "Best answer is a mix between the 2. Size up the plans just a bit, and make proportionally larger fan mounts for an increase in performance without really changing wing loading."

And also, would it be worth replacing the twin 70mm 12 blade on the f-4 phantom with twin 90mm 10 blades and about ( just to generally visualize ) how much bigger and faster would the 90mm 10 blade be compared to the 70mm 12 blade?
Thanks in advance!
 

Muquacksa

Member
And also, with landing gear, do I have to cut out a wooden mount for it and attach it to the f4 phantom? If so, what thickness plywood should I use?
 

Flitedesign 3d

Elite member
And also, would it be worth replacing the twin 70mm 12 blade on the f-4 phantom with twin 90mm 10 blades and about ( just to generally visualize ) how much bigger and faster would the 90mm 10 blade be compared to the 70mm 12 blade?

Twin 90mm will be a lot heavier than 70, also remember that if you dont scale up the model with the edf the intakes wont be big enough and you might need a cheat hole. I dont know which fans and batteries you have but assuming you have a 6s setup I can tell you that twin 90 is a huge setup, you will need two 120 amp escs and a like 2 6s 6000 mah batteries with 35+ c rating
 

Muquacksa

Member
Oh god, I dont think ill have the batteries for that. Also, for twin 70mm, what would be the optimal battery size for 4s 70mm 12 blade edfs and will a 80a esc work or would i need a 100a esc?
 

Muquacksa

Member
At the moment, im trying to find another suitable edf unit as the AliE seller declined my EDF jet order and I am waiting for a local RC shop to get some lipo batterys available. Probably going to take at least 1 month for me to start.
 

leaded50

Legendary member
for retracts, YES, you should use a plywood baseplate to spread the forces/ amplify the foam for the extra twist forces eg, the mounted place would get.. i use 2 - 3mm plywood, and havent got any wrecked foam around the retracts yet.
 

Mid7night

Jetman
Mentor
Alright, after numerous COVID and shipping setbacks, I think it’s finally time to make this F4 phantom. I’ve got almost everything ready to order, though I can’t find a landing gear similar to the one Mid7night used. I would like to ask, would this landing gear work? https://www.banggood.com/Two-Wheele...-p-1080692.html?cur_warehouse=CN&rmmds=search Although it isn’t very accurate, would it fit nice enough and do the job?

Great to hear you’re gonna build one!
Those gear probably would not work, since they are forward-folding and the F-4 is designed for inward-folding gear.

If you want to try and save weight, a number of people have successfully built this without any landing gear. You might need someone else to throw it for you, but removing the gear will make it a LOT lighter and improve its performance in the air.
 

Reeper

New member
New guy here.....thought first I would thank "Jetman" for providing the F4 Phantom plan! I enjoyed putting this one together.....

I thought I would share a couple pictures of the build now that I completed it. Have not Maiden flight this one yet but looking forward
to getting out to field and zip around ......

Pardon my mess in the shop background..... ; )
 

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