The F7 Becomes an F3

The F7 mechanism remained naked long enough. After spending a month evaluating various potential approaches to making a shell, I finally decided to get down to it. I printed a full-sized drawing, took it to my workbench, and started on a proof-of-concept shell. I'd also jotted down the overall dimensions of the prototype, and divided them by 450 to arrive at the shell's actual size: 1.32 inches long, 0.28 inches wide, 0.33 inches high.



My intention was not to make an ultra-accurate, prize-winning model; it was to experiment. In particular, I had an idea of how to imbue the tiny little thing with detail I could not possibly fabricate physically. My thought was to make a near-full-body decal that would present the grilles, seams, rivets and other relatively subtle surface details on the sides that would ordinarily be no thicker than paint in T scale if modeled accurately. The only details I'd have to fabricate would be the fans on the top.



I was quite surprised by how thick I could make the shell. The math was straightforward: the real thing is ten and a half feet wide, which is 0.28 inches in T. The mechanism is 0.20 inches wide, leaving a difference of .080, meaning the shell could be made from .040 thick sheet styrene. This turned out to be quite an advantage: it allowed me to easily file and sand all of the many curved surfaces.



As I predicted, the nose was a bit of work, especially since it had to fit around one end of the mechanism. I had to push the windshields forward several scale inches to make room for the end of the motor. But at the model's tiny finished size, I doubted this discrepancy would be noticeable.



I'd hoped that I might be able to complete the shell without having to resort to filler putty, but this was only a fantasy. I had to shape the nose twice to get it right, as it was misshapen the first time around: the headlight wound up way too low, and it looked like a Baldwin babyface. So I slathered on the Squadron putty and had at it again.



While the putty was drying, I made the cap-top fans and other details. Then I shaped the nose once more. Along the way, I learned a trick to compensate for the fact that the putty is too soft and porous to hold small, intricate shapes: I soaked the surface of the putty with CA, which sealed and strengthened it.



Finishing the little beastie was made harder by virtue of my choice of road name: CNJ, in the classic tangerine and navy scheme. I could have made things much easier on myself and gone with something like all-black PC. But I chose CNJ for a specific reason, and it wasn't because it's my favorite road: the yellow-orange stripe down the side makes the grilles clearly visible.



Using photographs I found on the Internet, I made four decals: the two sides (both made from the same photo, with the other side just flipped—with the lettering corrected), the lower nose, and the windshields. Printed on white decal material, the images were startlingly sharp for their size: the lettering was all still readable, and the windshield wipers were clearly visible.



The toughest part of the finish work was the nose, which couldn't be covered by a decal, and had to be solid yellow-orange. Unfortunately, I neglected to prime the dark green putty first, and so I wound up applying coat after coat of paint (which turned out to be a good thing—it helped smooth the still-rough surface of the putty). Making matters worse, I didn't have the right shade of blue paint on hand. In the end it was not a pretty sight, and I almost declared the shell ruined by virtue of a botched paint job. But, remembering that this was a proof-of-concept project, I decided to keep it, and disguise the flaws with a healthy dose of weathering.



For a proof-of-concept model, I think it came out rather well, even though it's technically not even finished—I've yet to make the fuel tanks and the front coupler. One little letdown I encountered was that there wasn't room for an LED to make the headlight function. It could conceivably be done if the shell around the nose was thinner; out of necessity, this one is all solid styrene.



Although I have my doubts, I do hope that someone at Eishindo is following my blog. This model would be so easy to manufacture—the mechanism modification would not be hard to replicate, and the shell would be a no-brainer. And since Eishindo ink-jets their shells, they could produce no end of colorful paint schemes.



Here's a video of F3 #56 in action. Please excuse the fact that I erroneously refer to it as an F7.