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Old 12-10-2020, 03:30 AM
chris190 chris190 is offline
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Join Date: Dec 2012
Location: cambridge, england
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Glad you like it! However, backwards progress today - this morning’s decision is to strip the wing covering I did yesterday because both leading and trailing edges are rubbish; sharp edge to the former, sinking between ribs on the latter, so redesign frame a bit and improve rolling/forming technique.

The 2d/3d process in brief is to stretch surfaces like wings so that the dimensions drawn in 2d plan and elevation become true lengths as measured on section (this affects the wing chord more than the span, plus always start from a fixed line such as the main spar position and measure back and forwards from this); for the fuselage, divide the length up into cones in such a way that you get as close to the curved profile as possible. Each cone section is then developed by standard techniques readily available online, except, and it’s a big except, that most fuselages aren’t true cones i.e. the shape at one end often has a different centreline to the one at the other and may/will not be a true circle!

In this case, you project the top and bottom lines of the fuselage shape to give an asymmetrical cone and use the perpendicular from the apex of this cone as the centre line for developing the boundary profiles of each end of the cone using the oblique cone development process, again readily available online.

As is so usual with the internet, there aren’t any instructions for dealing with this really basic problem and I have to say it took a great deal of trial and error to find out even this much but I’m reasonably confident that I’m right as the fuselage has worked pretty well.

All the best

Chris
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Fokker F36 scratch build 1/100 scale-50fa13b2-68be-4c42-89b6-9566aabf0902.jpg  
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