I am trying to model this electric piano from 1939 and am having trouble with the circled portion.
Any help provided would be most welcome.
Thatâs very much similar to this âround end cap on a wingâ thing, only without a backswing in the crossectional profile (your object is convex throughout).
NURBS round endcap.3dm (11.9 MB)
I would add that NURBS geometry in general does not like having too much of a curvature when the goal is to match a single surface to several adjacent edges, and still maintain G2 continuity. In highly curved cases like this one (about 180 degrees of bent surface, almost like a horseshoe) usually splitting the surface into a bunch of smaller pieces helps with the matching. This way, the surfaces remain single-span and adding extra knots is avoided. As an added bonus, the control points are more relaxed in comparison, especially when you view them from a side view.
NURBS round endcap + 4 patches.3dm (7.8 MB)
A single, highly curved âhorseshoeâ surface:
A series of smaller, less curved surfaces:
The same principle is valid for degree 2 surfaces that require an added knot to be able to go past 90 degrees of revolve, hence they need 4 knots to create a full true circle/cylinder.
Looks like continuity of the physical object between the end cap and the long piece is close to but not quite tangentical aka G1.
Hereâs a cheap & cheerful way to do such an endcap in a more controlled fashion, with G2 surfaces, forced to end at a 10° angle, for example. But maybe you donât need that much accuracy anyway after CNC-milling the timber and then finishing it with sandpaper, etc.
Endcap.3dm (2.1 MB)
Cheek Block.3dm (2.1 MB)
If the goal is just a quick visualization, I think using SubD is a great choice. Here is a quick attempt I made for your reference.
Cheek Block.3dm (2.1 MB)
Thank you all so much.
Iâm trying them all.
Thanks again.
T~