I stand corrected on a previous article. I originally made a misstatement regarding the capabilities of SolidWorks to create drafts on ribs based on curved surfaces with controlled root widths. As far as an explanation for this oversight, I can only say what didn’t work for me last week worked this week, and that my VAR has some new inexperienced people on their phone support. Here’s the basics that didn’t work before but work today.
SolidWorks does allow one to control the root width of a rib feature on a curved surface with the draft feature. This means that draft will diminish from the ribs base, even if it is from a curved surface. To apply a draft to such a rib, simply use the parting line option and pick a perpendicular plane or a parallel line/entity for the direction of draft. For the parting line, choose each of the edges where the rib intersects its curved surface base. If necessary, toggle the direction of draft. That’s it.Â
Of course, this method is still imperfect. The question is, why doesn’t the draft feature just know that I want to pull it from the root? It seems illogical to require a neutral plane at all since each rib has only two ends. Why not just ask the user for the end to draft from? I guess if someone wants to use draft to add angle to a rib long its left to right/up to down, then making this assumption wouldn’t work. I doubt that would be much of an issue however, since that is not what a rib nor a draft is supposed to be.
The alternative method I posted last weekend should be referenced as a case of bad practice that works and should only be used if nothing else does. Edit: however, it is a good demonstration of how to get a line along a curved surface into a sketch.