Fillet bug on concave arc

[matt.birchall]

First post here (be gentle please!)

Odd results, profile of remaining material is not as expected.

My design uses a sketch with some tangential arcs. I'm trying to understand what makes the fillet tool fail to calculate (originally I was using fixed point splines but I have switched to using arcs to simplify the issue) and have stumbled across a reproducible issue.

Using a 6mm radius on the fillet generates a sensible result

but a 7mm or 8mm radius generates this

9mm radius generates this...

10mm radius fails to compute. It says "The fillet/chamfer could not be created at the requested size. This might be occurring at the ends of the selected edges."

I am trying to understand where and why the compute failures occur - the error messages are somewhat cryptic IMO!

In any case, the results at 7 and 8mm look buggy to me.

Is there an explanation for the 10mm radius behaviour?

[jeff_strater]

this does appear strange - I've sent it off to the modeling kernel folks to take a look at.  Thanks for sharing the design.

[matt.birchall]

Thanks for taking the time to look at this. I'll be interested to hear what the kernel folk think.

[jeff_strater]

the extraneous arc/face result at 7 or 8 mm is a kernel bug.  They will look at the underlying cause to try to find a fix.  

[matt.birchall]

Thanks, looking forward to a release at some point (not holding my breath though!) Is the 9mm result expected or is that a separate issue? The resulting shape curves back in towards the base, the calculation seems to be adding material to the original extrusion, and the ends of the shape are vertical rather than radiused.