Football Helmet: While it would be easier to to use the side profile and bottom profile as direction 1 curves, and the middle profile for direction 2, the result would be a 3-sided surface with bad flow of the UV curves (all of the control points of the NURBS surface converge at the same point and create a singularity. This would prevent the surface from being shelled or offset, a critical step in building a helmet.
Instead, a sketch consisting of a partial ellipse is used to provide a 4th side for the surface. As a general rule, all lofts and boundary surfaces should be 4 sided. Use the fill surface for everything else.
Download:Individual Parts Complexity: Moderate Features used: Tangency, Flatten, Pattern
View all the Part Reviewer Tutorials here.
DraftSight Download: In conjunction with DraftSight, Dassault Systèmes’ 2D CAD product, the 2D drawing(.dwg) file of the Self Centering Ring tutorial is now available for download here.
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