Fillet inverting itself

[tom.davie]

Hi,

I'm having issues using the sketch fillet tool.  The preview as I work with the tool is exactly what I want it to create, but as soon as I push enter, the finalised fillet goes crazy.  Any ideas who's going on here?

[henrycasson]

I could not replicate the problem. I notice that there are other parts of the sketch selected at the time that you do it. Maybe they are interfering. if you just draw the two arcs and one line, it seems to work normally.

[tom.davie]

As far as I'm aware, none of the rest of the sketch is selected.  I could well be wrong though!  What's indicating to you that I do have something selected?

[tom.davie]

For reference, it certainly does seem to be to do with other geometry interfering with the filet.  Here's another video of adding a number of filets, as you can see, each one progressively screws up the other geometry in the sketch:

[tom.davie · Accepted solution]

I found the issue!

I had constrained some of the corners to be right angles, which had caused the splines to have cyan tangents (which I presume mean that the tangent was entered by hand, and fusion 360 shouldn't go editing it under me without my permission).  Adding fillets were those constrained tangents were caused the issue, deleting the blue tangents got me back to a good state.