F-4 Phantom (oz14306)

About this Plan

F-4 Phantom. Radio control sport-scale model, for IC ducted fan. Wingspan 44-1/4 in.

Quote: "At last, a simple, easy to build ducted fan model (for .65 - .90 DF engines and a Byron fan unit). Fun scale F-4 Phantom, by John Whitmore.

It all started with a long term love affair and a heavy dose of jealousy. No she wasn't a gorgeous brunette, she wasn't even a blonde, but boy she was sexy. Actually she had great curves and was a beautiful shade of blue. The Angels loved the way she responded to their every command. Hey! you guys. what do you think we're talking about here, some women of the night? Heck no, the F-4 Phantom! The Blue Angels flew her remember?

As you might expect this was a complex undertaking. The F-4 took a few months of heavy research before I was able to produce a set of working drawings that I was comfortable with. The essence of this design being a simple box type construction. Since the F-4 has large intakes and abundant wing area, it lends itself perfectly to a ducted fan model. The F-4 builds very fast, and when you look at the drawings, you can see how close to scale it really is.

A famous quote from a very famous modeler, Charlie Grant, was Build and add lightness - l believe it, and you should too! Most of us fly off grass and don't have the luxury of paved runways, you want to keep the thrust to weight ratio as high as possible. So if your jet weights 10 lb, you want at least 10 lb of static thrust, which will be one to one. The higher the thrust to weight ratio the better your model will perform.

Plain nitro pipes are too darn noisy. Muffled pipes are only a little quieter and that's like being only a little, pregnant. I needed something that offered a major improvement in sound reduction. Having read a lot of positive reviews on the Soundmaster mufflers I decided to call and find out if there was a high performance ducted fan pipe for pusher installations available. So I gave my old buddy, Bob Davis, of Davis Diesel a call to find out if he had developed such a pipe. I was delighted to find out, that although there were only a limited amount out in the field, results being fed back showed sound drops of over 8 DB A when compared to other muffled pipes available.

In pursuit of doing my part to improve the state of the art in our wonderful hobby, believe it is perfectly okay to get something for less. Maybe a lot less. Maybe even free. It isn't that I'm cheap or anything, let's just say if there's a way to get something for less (stealing is definitely out since I'm too nervous) I'll find a way.

I decided to pay a visit to the Soundmaster himself. Just as an aside, I've often considered using one of his products on him, especially when he appears to be getting the best of me in a debate which believe I should be winning. But a better and more helpful person I would be hard pressed to find. So I appealed to his good nature and listened to him expound on the supposed virtues of his latest gizmo's for a few hours, then left for home clutching a brand new Soundmaster high performance turnaround pipe. Free I might add. The only promise he extracted from me, was to provide him with data.

Construction: Start by tracing and cutting out all bulkheads, patterns, and tail feathers. Drill fan mounting holes in bulkhead F-4 for blind nuts. I chose to use Soundmaster Iso-Mount's to deal with one facet of noise reduction vibration induced noise. This aircraft design lends itself to either tractor or pusher fan. l just happened to have a Byron Fan unit laying around gathering dust. I chose to isolate the Byron fan assembly, with Soundmaster lso-Mounts. Follow manufacturer's instructions on installation. And by the way, they install easier than plain blind nuts. Now remove the fan assembly and put it aside.

Fuselage: Let's start with the bottom first. Cut 10 pieces of 4- wide 3/16 x 10 in long sheeting and lay side by side. Now glue to form bottom. Draw a centerline down the length using a soft pencil. Mark positions for bulkhead F-4 and F-5 and trim outline to match top view. Please note that the thrust tube has a 4 degree down thrust angle just like the real F-4. Make a 4 degree angle gauge using plan as reference and install bulkheads F-4 and F-5. Glue in 1/2 in balsa tail blocks at F-5 locations. Now glue down 1- triangle stock taking care to position flush with edges.

Thrust Tube: The thrust tube is fabricated in two parts from 1/64 plywood and you must first determine the bending direction prior to cutting. The front section is cut 4 in by approximately 20 in long. Use F5 through hole as gauge, then trim for butt joint. Glue the joint and add a 1/4 in strip of 1/64 x 4 in plywood to OD for seam reinforcement. You may now trim the plywood reinforcement back 3/16 in to clear the bulkhead diameter and glue in place.

The rear section is 20 x 18 x 1/64 plywood. Cut and insert this through F-4 into F-5. Mark overlapping plywood edge, remove and trim with straight-edge. Glue the butt joint and reinforcing as you did for the front section, then reinstall and cheek fit prior to gluing. Trim excess even with outer surface of F-5..."

Direct submission to Outerzone.

Scan by MarkD, cleanup by Circlip.

Supplementary file notes

Article.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction