Composite vs Built up balsa fuselage for F3A
#1

Hello
While watching YT videos for F3A in Japan, I noticed that many of the 2m planes are traditional built up sheeted balsa/formers/stringer (albeit with a former carbon nose) construction rather than composite fuse construction
Is there an advantage to this or simply due to the availability of F3A kit form models ?
Would a composite fuselage be more rugged (say grass field ops) than a built up balsa fuselage?
I must admit, the build quality and paint finish on many of these models is impressive, amazing build skills (way beyond anything I could ever attempt!)
While watching YT videos for F3A in Japan, I noticed that many of the 2m planes are traditional built up sheeted balsa/formers/stringer (albeit with a former carbon nose) construction rather than composite fuse construction
Is there an advantage to this or simply due to the availability of F3A kit form models ?
Would a composite fuselage be more rugged (say grass field ops) than a built up balsa fuselage?
I must admit, the build quality and paint finish on many of these models is impressive, amazing build skills (way beyond anything I could ever attempt!)
#2


I have a friend in Japan who is a renowned F3A builder. He mostly builds FlightHobby kits for himself and others. The key point I think is that the really good builders can take advantage of better wood and better techniques to produce a lighter model. I think it is a real point of pride and status to have such uber light models via wood construction. One thing to note, it takes an equally skilled fabricator to produce a glass layup fuz that is really light, not to mention the equipment and exotic materials often needed to get to that point. Techniques of carefully measured resin applied to the mold, extraction of any excess resin during layup, a wide variety of carbon, wood and foam components for strength are all skills that take many years of testing to actually produce strong, light parts. With today's massive side area fuselage designs, these techniques are even more critical unless you want a fuz that twists, tincans, or even breaks with routine handling. For any shortcomings that a built up fuz might have, it is usually a pretty solid structure and using the lightest wood and finish techniques is relatively simple to keep reasonably lightweight. You are correct, these guys are really good at applying the final finish. They are literally sanding/polishing every single layer till the end result is just barely enough coating to get the job done [many videos are floating around showing these skills]. This takes skill, nerve and lots of hours....live and die by the gram scale, I guess.
To your question about ruggedness on a grass field, I thing there's the good chance that a well made glass fuz is going to withstand more abuse as long as the LG area is reinforced. For my friend, it is often a matter of repairing the damages to a built up wood fuz that matters. These guys are also masters at repairing the build up fuselages like they were "wood surgeons" or something. They just dive in and patch them back good as new in very short order. I think once you have the skill to build it, you also have the skill to repair it quickly. Same could be said for a glass fuz but that's a skill set that is not a common I'd say, at least in terms of keeping the repair as light as the original undamaged fuz.
To your question about ruggedness on a grass field, I thing there's the good chance that a well made glass fuz is going to withstand more abuse as long as the LG area is reinforced. For my friend, it is often a matter of repairing the damages to a built up wood fuz that matters. These guys are also masters at repairing the build up fuselages like they were "wood surgeons" or something. They just dive in and patch them back good as new in very short order. I think once you have the skill to build it, you also have the skill to repair it quickly. Same could be said for a glass fuz but that's a skill set that is not a common I'd say, at least in terms of keeping the repair as light as the original undamaged fuz.
Last edited by ted32776; 09-06-2023 at 06:32 AM. Reason: error
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wattsup (09-06-2023)
#3

Thank you for the reply
I didn’t realize the level of support that F3A seems to have in Japan. I agree, those models are worthy of the pride in building and in ownership
I did watch a YT video that detailed what went into fabricating the Glacial composite biplane. I had no idea exactly what was “under the skin” until I watched that video
I didn’t realize the level of support that F3A seems to have in Japan. I agree, those models are worthy of the pride in building and in ownership
I did watch a YT video that detailed what went into fabricating the Glacial composite biplane. I had no idea exactly what was “under the skin” until I watched that video