How to simplify blended/multiple edge fillets?

tarik_ansari

I am filleting the bottom of a molded part and encountering a limitation of the fillet feature:



The problem is that the fillet is too large to fit the edges, the obvious solution is to pick the nearest tangent edge. This can be achieved by creating a sketch meeting this criterion on each end and lofting the resulting sketch surfaces. These steps are required vs a single sketch and extrude to meet draft constraints.



A similar technique can be applied to edges that present convex challenges by finding the curve that creates the minimal area while using radis that are greater or equal to the fillet radius. -- I approximated the minimal area solution, I am not sure that the mathematical solution to this problem is.



There is a third case when the drafts create a transition where an edge disappear, but I assume would be handled the same at #1, and should be taken care of by the loft feature:



My question are:

1. Is there a simpler way to achieve these fillets? I am generating a ton of manual edits and feature history to create these, especially when dealing with ribs with many edges.
2. I saw a mention from a team member back in 2015 about possibly implementing "blended fillets", is this what this would achieve? What is the status on it?
3. Have somebody wrote a custom feature for it?

NeilCooke

For cases 1 and 3 use Delete Face / Heal on the sliver face then add the fillet. Not sure about case 2. 

tarik_ansari

I have experimented with solving this problem with delete face/heal, the problem is that this is not an equivalent solution, nor is it optimal as it will result in either using more material than necessary and/or cutting a wall shorter than it was. Furthermore, it requires the designer to choose an option out of several choices when there is no design intent --  if you take the example of the convex edge problem.

tarik_ansari

As a quick update to my last comment: delete face gives the correct result for case #3 because the tangent constraints end up being the same. It can also work for a narrow set of scenarios and end up giving the ideal solution.

However, it does not work for case #2. It also does not work for case #1 because the delete face feature will fail to heal due to the curved direction of the surface.

NeilCooke

For Case #1 what you really need is a face to face fillet - create or vote for an improvement request in the category on the right —->