The original model and fillet was generated in MOI.

Hi Niko - so yeah it looks like MoI's filleter did not quite get a clean trim at the ends of the fillets in that spot there.

That's one of the issues that makes filleting difficult - trying to get a clean intersection where 2 fillet pieces cross over each other where they are tangent or very close to being tangent.

Things that come to the same tangent kind of have more of a zone where they are overlapping in a certain sense which is much harder to calculate than a crisp intersection where things collide at a 90 degree angle or something like that.


So at any rate, the actual problem here was not really in the booleans but more in the filleter.

- Michael

what's the solution?

Hi Niko, well the error is pretty small in size, do you actually need it cleared up?

If you just want the boolean to work, the solution I posted previously will work (scale down, join, scale up) for getting it into a solid and getting the boolean to finish.

If you need a better fillet in that spot, do you have the original unfilleted shape that you could post? Possibly doing a scale UP first before doing the fillet could actually help with the fillet, it may make the fillet be denser and more accurate and possibly intersect better.

Another possibility for fillet quality is to try using a surface/surface fillet instead of the edge-based filleting. To do surface/surface filleting you break things apart into individual surfaces and then just select 2 surfaces at a time for fillet construction. You may need to do some manual trimming for this method.

- Michael