Re: Maybe tracing is easier but ...

David J. Gall


If your intent is to duplicate the existing QAC shape I would caution you that, although "CAD is fun" it can also lead you astray. The state-of-the-art in the early 1980s was compass and protractor and a wooden batten as a spline; the CAD equivalents are *not* degree-three curvature-continuous NURBS curves and surfaces. Stick to degree-two conics or arcs of circles joined tangent-continuous for cross sections and nothing more than degree-three single-span curves in the longitudinal direction. If more than one degree-three span is needed longitudinally, join degree-three splines at their ends using nothing more than tangent-continuous joins.

If, on the other hand, your intent is to make it "better," first, define "better," then go for it! Coolio!

(If you're surface modeling in SolidWorks, well, there's no hope for the world.... ;P)

David J. Gall

-----Original Message-----
From: <> On Behalf Of Johannes Weissmann
Sent: Thursday, October 6, 2022 3:41 AM
Subject: Re: [Q-List] Maybe tracing is easier but ...


CAD is indeed a lot of fun. I finished the first surface model of the Q2 fuselage yesterday. Not perfect yet, but at least it is spanning the whole fuselage now.

On 06/10/2022 06.27, Robert Schmid wrote:
... this CAD stuff is fun too. First version of panel test cut is

CAD still needs some fine tuning but not bad for a start.
Robert "TheFrisco" Schmid
(408) 805-5450 ( ) ( )

Love building planes almost as much as flying. Latest completed build is "Loki", a Chinook Plus 2 bush plane.

Johannes Weissmann
Avenida de Mariano Vicen 27, Piso 2-I | 42003 Soria | Spain
mail: jo@...
fon : +34 615 81 81 40

"The truth, as always, will be far stranger." [Sir Arthur C. Clarke]

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