RandyBond

My Feedback: (1)

I'm having a miserable time getting the plastic nacelles on my F4 to fit the fuselage. Has anyone ever just used balsa sheeting for the nacelles? I'd be interested in hearing if that's a viable solution to my problem.


Thanks - Randy

Capt Jim

My Feedback: (168)

Yes, plastic parts seldom match up easily with balsa. The attached pix show mine with lots of fairing compound to fair them into the fuse'. We modified the kit to include a fully sheeted wing, and then we totally covered it in very thin fiberglass cloth, filling and sanding much more than the average person would tolerate, and then a nice spray paint job...no plastic film. The results were worth the effort as you can see in the finished pic. This plane still sits un-flown...a year after it was finished. It is just too pretty to take a chance on crashing, so I use it for an occaisional display. Good luck with yours...and please do let me know how it flys.
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skydeuce

My Feedback: (30)

I have a GP Phantom I getting ready to start and want to do it in the Blue Angels Scheme. I bought graphics already from Die Hard. I have seen another article that used the same technique of Bondo and glass cloth. How heavy did yours come out to be? It already seems to be a pretty fat kit. With knowing you were going to use glass, did you lighten the frame up in any way as you were building? And what engine did you put in - it looks like a .61FX from the photo. I was thinking of a Rossi .61 with a rear exhaust to clean up the lines a bit and get some extra RPM.

Capt Jim

My Feedback: (168)

I have not been able to weigh it, but of course it'll be a little heavier than a stock F-4 since it has the wood wing sheeting, and glass overall and paint, but right from the beginning I planned on using the OS91FX which is what you see installed. The motor is exactly the same size as the 61, and weighs a couple of grams LESS...I guess thats because they bored out a 61 to make it a 91. Another mod' was to change the retract openings so as to accept longer "legs" needed for prop clearance.

skydeuce

My Feedback: (30)

Capt Jim,

I stand corrected, I think I may try and cram a .91 into mine as well. I wasn't sure it would fit, but now that you mention it, they are about the same size. I was deceived by the GP note about trying not to overpower the airplane. Better to have and not need than to need and not have, right! Could you have used a 3-blade and maintained the shorter legs to reduce stresses on the landing gear mounting plates?

Capt Jim

My Feedback: (168)

A three blade prop was considered, but since I thought there was a need for maximum thrust, the feeling was that the three blade would be less efficient than a two blade, and more expensive, and additionally, not a normally stocked item at many hobby shops. As for the 91 vs a 61....maybe in the distant past, there may have been a weight penalty between the two, but now, with the current OS "FX" series....the 91 is actually a few grams lighter, in the very same case size. That said, I cannot understand OS continuing to manufacture the 61. Since we are getting into the F-4 build, another mod that we incorporated was to actually build a tunnel through the nacelles allowing air to really pass all the way through, rather than be dammed up at the front with a sealed off face, per the GP plans. That came about in a discussion af aerodynamics between a group of flyers that know more about Krispy Kreme doughnuts, than aerodynamics. But we did it anyway, and it looks cool and is a great little item to brag about. Now...the reason this plane has not flown....A second F-4 was built...by another club member, pretty much exactly like this one...and flights #1 and #2 were fine. Flight #3 attempted to utilize flaps in a crosswing....the result was a very unstable glide slope to landing, at low speed, allowing considerable wobbling in yaw, ending in an ugly crash. Major repairs were required, including the reattachment of one of the wing tips. All subsequent flights, (three to be exact), were very unsatisfactory. Each produced another crash and lengthy repairs. It is possible that he was unable to reattach the wing tip at the exactly correct angle, thus causing the instability...which only made itself manifest at low speeds...like upon landing. Take off, and normal fast flight were just fine...but ya gotta come down sometime, and thats where the problems arose. Another consideration was Pilot fear. The plane took many months to build, with a great amount of care. The first crash grounded the plane for another month or more....with much more labor involved....and of course that just increased the worry factor. So...my F-4 remains unflown....in fact...no electronics has ever been installed. I like to look at it because it is simply a georgeous specimen, but I will most likely sell it...unflown. My interests are now into some much larger IMAC planes and some gas powered scale, so this F-4 is just an expensive ornament these days. I hope this info is found to be informative, and helpful. Good luck with yours.
Jim
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skydeuce

My Feedback: (30)

Capt Jim,

Thanks for the info, I may try and add the wind tunnel idea to my build sequence. I imagine if I installed some of the small whistle devices inside the nacelles I might actually get a cool jet like sound - or a horrific screeching noise that will get me banned from the flying field. Won't know till we try.

Yours is a beautiful specimen and I hope I can come close to matching your quality in finishing it off, and I'm sure I will have the same trepidation when it comes to flying it. Of course I will not have the added insight of watching somebody else's burn in, repeatedly apparently, to bring me back to my senses. I've read a few reviews on it that recommended learning to land fairly hot with it due to wing loading. I've been reviewing the manual to find potential weight savings that make sense (ie, foam core wings versus built-up). From what I understand about aerodynamics, which is in the Krispy Kreme category also, is that the weight versus engine size argument isn't necessarily as important as the weight versus wing area/wing loading argument. Of course the kit box weighs about 40 pounds and I'm wondering how I'm supposed to end up with about a 10 pound aircraft (unless there is a lot of laser cutting excess) when its all over.

Again, thanks for posting pics of your plane, she's gorgeous. And thanks for the .91 and open engine ducts ideas, I'm sure I'll use those.

Do you have any other insights into building that GP may have not included in the manual that you discovered while you built yours?

Capt Jim

My Feedback: (168)

The actual build was by a local master craftsman...for a fee...a very large fee....that is why this F-4 cost me so dearly, and significantly jacks up the worry factor. Although we discussed each step in the build, my participation was largely just to sign the checks. However, I can relate some info about the kit shortcomings. The plastic parts are a poor fit. In fact, some of them do not fit...somewhere around the tail section especially. It required an improvised work-around to get things back on track. I like your whistles in the nacelles idea. I may want to try that...if I ever get the nerve to put this bird into the sky. Another thought we had was to use a gyro..at least on the rudder so as to make the landings and take-offs nice and straight. Then Futaba came out with a two axis gyro....maybe even better...putting it on both rudder and ailerons. The way I understand the operation of the gyro is that it ignores the plane movements that were commanded by the Tx, but responds immediately, with an appropriate correction, to any variation of yaw or roll that was not commanded, but rather induced by wind, etc. Competition flying usually allows one surface to be gyro influnced, but beyond that...who knows....but then this is not your typical competition plane. It is not an IMAC performer and it fails in scale with that prop up front. Gee...it makes me ask myself... why did I do this? If you would like to email the master builder I can pass along his email address for you. He can talk a great deal on the failings of this plane. heh heh. Maybe a lot of things you really don't want to know.
Jim

DavidAgar

My Feedback: (108)

I am not sure if the problem that you are having is related to the size of the plastic parts, but I do know that the early release of the kits had plastic parts that were to small. Great Planes sent out the right size parts to kit owners who asked for them, however I am not sure about today as this all transpired a few years back. If this is the issue, maybe contact Bax here on RCU and ask him as he is the Great Planes rep. Good Luck, Dave

Capt Jim

My Feedback: (168)

Hi Dave. Yes, I had heard about that too, but it's way too late to replace anything. I must have gotten an old kit...I did pick it up here online and that was over a year ago at least. Who knows how long the first owner may have had it tucked away. But anyway, the price of the kit was attractive and it came with the good Robart retracts. In addition to the fine glass coat and high gloss paint finish, this F-4 is also highly detailed in the cockpit. I was not intending for it to be so detailed but this master builder just would not let it leave his shop without the fine touch. He actually built two complete instrument panels...front and rear, and has a little camera, and other instruments...just like the full scale. The pilots helmet, all hand painted, has the word "Thunderbirds" with little stars, all across the back side. Just like the real ones. I said..."no one will ever see it...the seat back blocks out any possible view of the back of the helmet"....He said..."I will know it is there". Thats the kind of scale guy he is. He is an absolute artist...I cannot say enough to praise his excellent work. The downside to all of this is simply that, most of the guys he builds for, decide not to fly the final product....they get scared of it...it is just much too nice to take a chance on messing it up. I would bet that the full scale Thunderbirds would be happy to display this one at their showroom....except for that prop up front!!!

bob27s

My Feedback: (19)

Jim,

I recently aquired and older F-4 kit, and emailed Great Planes asking about "buying" updated plastic parts for the F-4. They are available, and not that expensive. I will have to see how mine fit up first.

Also, I know off hand of 4 of F-4 Phantoms flying with Jett SJ-90 engines up front. One was done as a review aircraft for a ("european?") magazine a few years ago when the kit was first released. All of them report the plane flys very well. It's clean and fast, but in some flight regimes (high alpha - tight turns) it can create a lot of drag and lose energy rapidly. Just like the full scale. From the one I personally had the opportunity to fly, it was a very nice flying aircraft. Reminded me quite a bit of flying my old EU-1A. Performed very nice slow rolls Landed quite nicely, nose high about 5 deg... about 1/4 power on..... smoooooth!

I had a link to a good photo and construction review web page for the phantom...but it appears to not be active any longer.

Bob

CafeenMan

Capt Jim - That is a nice looking plane. Obviously a lot of work went into it.

These comments aren't directed at anyone in particular, but I read a few things that I want to respond to.

First, if you use contest balsa, then fully sheeting a wing shouldn't be more than a small amount heavier than a D-tube. The exact same amount of glue is used to hold on the sheeting and cap strips as is used to hold on a full skin. E.g. the entire perimeter of every rib gets glue.

Second, glass cloth and paint can be as light as an iron on if the original construction was good (minimal or no filler needed). Primer should be almost totally sanded off unless a light color is going to be used. In that case an even coat of primer is necessary but it can still be thin.

Every coat of the finish needs to be sanded. Most people who end up with heavy paint jobs put on too much paint and don't sand between coats.

Assuming a model is a sport model (not a decked out scale model) then it can be glassed and painted and come in at a comparable weight to the same model covered in Monokote. Paint is just a heck of a lot more work.

I have a long tutorial on my site regarding fiberglassing. The model I glassed for the tutorial did not receive primer or color coats. It received clear poly which is a lighter finish than regular paint and primer but not significantly so. The finished model has 600 inches of wing and weighs 4-3/4 lbs. The model would fly well up to 6 lbs and it's significantly below that weight.

Rustik

Capt Jim

My Feedback: (168)

Hi Bob, and thanks very much for the flying report. As I had mentioned earlier, one big reason for me not flying it is due to having heard nothing much about it's flying qualities...It seems like I only heard the bad news. And then Great Planes discontinued the model...that gave me another worry that possibly it was prone to inflight instability. That coupled with the fact that my F-4 is soooo pretty, and so well done...I would hate to see it damaged. A few more of these happy pilot reports and I just may begin to install servos.
Thanks again for the good news.
Jim

CafeenMan

Capt Jim - if you did decide to fly it, how difficult would it be to cut the openings now? I would think that you could use a Dremel to make the openings and then paint the inside of them with fuel-proof black paint and touch up the openings with whatever colors were originally used.

What would concern me would be internal pressure trying to tear them off the plane. It looks like yours are attached solidly though.

Capt Jim

My Feedback: (168)

CM..Regarding your comment about cutting openings in the plane....are you refering to the air flowing thru the nacelles? Mine are open, with a fabricated air tunnel built inside. It is not a straight shot, but air goes completely thru. This was one of many design mods that I had planned right from the beginning. As for ripping the nacelles off...I doubt it...they are glassed in place. The entire plane is encased in a very thin glass cloth covering, and sanded extensively, until all remnants of the builders fingerprints were gone from his fingers...a bit painfull, and an awful lot of work. We tried to think of all the options before starting the build. That made construction go much more smoothly as the project progressed.
jim

CafeenMan

That is what I was referring to. It must have been someone else's post who said he left them closed.

Anyway, I think you should fly it. I would if I thought it were flight worthy, but obviously it's your investment, so my opinion doesn't count.

popf22

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bayareajeff

Where can I find one of these kits? Since it is discontinued would anyone be willing to sell a copy of their plans?? I have seen this kit a few times and would love to build one this winter.

Jeff

mduslick

My Feedback: (1)

Is it possible to convert this plane from glow to just a plain electric (still prop driven) with lipos. I already have the plane and would like to build it, but I think it would be really nice to be able to go electric if possible. What motor and prop combo is there that could handle a plane this size?

Capt Jim

My Feedback: (168)

Quite recently I had an opportunity to see one of these Great Planes F-4 kits actually fly. The owner had powered it with a 90 size two stroke, and it seemed to fly well. Not blindingly fast at all, but quick enough to be entertaining. He landed it very HOT, and said "it likes it that way". Presuemably he discovered stalling difficultys at slower speeds. He offered that his wings had their tip dihedral dramatically reduced and that (crash induced) modification made it a better flying plane. He did not employ retracts, but rather fixed gear. That was a weight saving, and probably makes the gear infinately more reliable. The pilot claims to have many many flights on it, over the years, and the less than perfect close up appearance gave testimony to that fact. The plane was nicely detailed, in a military scheme, and made a good presentation at a warbird flyin. I continue to be uncovinced that it is a good flyer, and I suspect that may be cause for GP discontinuing the kit. Mine remains grounded...but looks pristine in its museum quality Thunderbird scheme. It is also for sale for the right price. Until then, it is a specimen, "under glass", placed on display at certain few functions.
Jim

GeeBeeMan21

My Feedback: (110)

some guys are like car guys with trailor queens...every new guy i train, i tell him if your afraid of crashing, then your in the wrong hobby. What fun is it too look at something under glass all the time? If you want that, quit building flying models and go to plastic models lol. No offense, the hobby has something for everyone I guess. I say fly it and enjoy it. If you cant afford to crash it, then you shouldnt have built it. I wish you luck with whatever you do with it...

gutmark

I built one a few years ago for a friend. It's a beautiful airplane when finished. This was an early kit with the bad plastic so I called G.P. and received updated parts within a week. I installed retracts, tip tanks, and a tuned pipe which I ran through the right nacelle. The plane was a lot of work but it was worth every minute - I would love to build another (as soon as I finish my gold edition corsair and D.C. F/A-18!).

Bax

My Feedback: (11)

The Great Planes F-4 Phantom kit was available from 1998 through 2003. Production ceased because the kit's life cycle had ended. Like all models, including Ultra Sport 60's, Super Sportster 60's, and Big Stik kits, it had run out its product lifespan.

If the model is kept within the recommended weight limit of 10-11 pounds, it will fly nicely. Get it overweight, and you may have difficulties with takeoffs, landings, high-G and low-speed maneuvers.

bayareajeff

If any one is interested... I have this kit in the Box.. with some additional insights from a guy on RC universe. I am thinking of letting it go. The Seller wanted me to verify the contents when I got it. Other than that I have never had it open.

Thanks..


Jeff
[email protected]

miserynitro

My Feedback: (8)

i also have this kit new in the Box, never opened.... did you take any pics durning assembly?? i am keeping this plane, one of my favorites.... might sell for the right price but... when it comes to building planes, i am a rookie i guess... just wondering about pics of assembly, and maybe any hits you can provide to me, to make my life ALOT easier.... thanks!!