Default sketch fillet radius too big for small elements

[Henrik_Horlin]

In a sketch, if any of the two lines (or arcs) meeting in a point (confirmed intersection by trimming) is shorter than the initial suggestion for a fillet Fusion 360 will only say that it can not create the fillet, no explanation why.

Try by making two elements and adjusting the lengths. Adjusting after fillet creation keeps the fillet, Adjusting the fillet to desired size works. But if the initial elements will not touch the resulting initial (suggested?) fillet radius it will not work.

Is there a setting to determine initial fillet size? When doing it in 3D it starts a 0, why not in sketch? Mine is set at 18 mm which is seems very arbitrary. 

[ryan.bales]

hi @Henrik_Horlin,

Can you upload some screenshots or a screencast of this? 

I cannot seem to reproduce this behavior. The fillet suggestion is dynamic based on entity length and adjusts accordingly.

[Henrik_Horlin]

I've tried some more in a new sketch and the fillet is now changing dynamically depending on element length, it is working as expected except when dealing with inside of arc-segments. (se next paragraph). I get the notion that sometimes Fusion faults in the dynamic calculations or updates in the view panel, do not know why, maybe random background process that overloads.

I did a test with default fillet suggestion with some lines intersecting a circle. (see image). It fails somewhere between 33 and 41 degrees.  Lines made from a circular array (12 in 90 degrees). I don't have the time to do a more detailed test right now. It only fails if the fillet is on the inside of the circle, that I could tell.

The radius is consistently 15 mm even if the arc shrinks with each fillet. I select the arc first (closest to the vertical line) and work from left to right.