Fillet on this would switch sides

[karthick_241187]

Hi Friends,

I used round tool over a surface edge, I got a message in Prompt line as: Fillet on this edge would switch sides.

I am not able to fillet that edge.

Surf Fill. Tool also not working.

Could somebody explain me the reason for this issue, also how to solve this issue.

Thanks in advance for u r reply.

Karthick. P

[JohnDixon8251]

Hey Karthick,

Sometimes because of the relationship between 2 surfaces, the fillet will flip, so if the fillet starts out as a concave surface (for instance) , at some point it flips to a convex surface. This sometimes happens when you have 2 surfaces that curve away from each other and then curve back towards each other. See the attached image. The easiest thing to do is use birail or profile blend, so you are determining the sections instead of the tool doing it.