Hi Steve, thanks for reporting this bug.

That is a problem in the geometry library's fillet mechanism.

If you try that same shape with the "straight corners" option in MoI v1 it just produces nothing - in MoI v2 I've made some changes to try and return partially calculated results if there was an error in some part of fillet processing rather than just completely bailing out. That's why you get that result here with the fillets separate from the main solid. That way you at least get something to work with.


> or is this something you would need to fix up
> yourself at some time?

I'm not really confident about fixing up things way down in the guts of the filleter myself, it's quite complicated. It's probably something to be fixed by the library authors.

It kind of looks like it may be some kind of categorization error.


To finish it off, you can do one fillet with "Straight corners" turned off, which will make the side parts that you need, then you can copy those, and paste those into the one with "Straight corners" enabled, and trim the other parts that the fillets touch.

- Michael