Re: Maybe tracing is easier but ...
David J. Gall
Johannes,toggle quoted messageShow quoted text
Try to stick to degree-two curves (conic sections) as much as possible, and fit them piecewise with tangent continuity at the joins. Use the control point "weight" on the middle control point to adjust the amount of curve for each degree-two conic curve. This is how the P-51 was designed and (except for the possible occasional use of a French Curve) is likely how the Q2 molded fuselage was formed. (Also much TLAR freehand drawing....)
David J. Gall
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Johannes Weissmann
Sent: Thursday, October 6, 2022 8:43 AM
Subject: Re: [Q-List] Maybe tracing is easier but ...
At the current stage I simply tried to reconstruct the existing shape based on the available plans and templates.
Basically, I used the fuselage jig and bulkhead templates as reference and in addition traced the fuselage profiles from the three-view of the plans. The templates are to scale, the three-view needed some scaling.
Based on that, I tried to make the templates and bulkheads match with as little error as possible. The main difficulty is to exactly locate WL0 and WL15 as I could not find any references.
Currently, there is no limit on the degree I used to generate the curves. Some curvatures from the templates just can't be fitted with three-degree splines.
Here is what I am not sure of:
What I would *like to do* now, is to construct a design that matches as close as possible with simple mathematical forms.
What I don't know because I am not an aeronautical engineer (I am a
physicist) is how much I am getting into the realm of aircraft design or if the deviations from the original are small enough to not affect the resulting aircraft performance and specs.
On 06/10/2022 14.28, David J. Gall wrote: