Hi Steve,

I have struggled with this since trying out MoI. I love MoI but it takes a lot of patience and trial and error. I have found what drives the Boolean and fillet failures/variable results is the number of points that define the lines/arcs/curves/circles etc... Also, how those are broken up and joined together. Using show points and the rebuild command is the key. Then do all your ops and see how it works out. Repeating this over and over you will see how widely the results vary. Unfortunately it is almost impossible to make the same model twice unless you can remember every single setting along the way. Moreover, you have to have the basis for the booleans setup exactly the same way every time. This obviously isn't really feasible unless you have very few curves you are working with.

Right now, and I am still experimenting, I have found changing any arc to at least 9 points and circles to 36 points alievates a lot of problems. Curves sometimes have to have more points added same with elliptical segments. Lines are usually fine with the default 2 points however making them 3 points changes how all the boolean ops work. Also it is helpful to rotate solids to get the seam out of the way on occasion.

It is a really good idea to zoom in and look at all your small features. With lighting set to metallic you can usually see issues from a farther distance out. The pain of it is, you may not discover a problem until the last op, usually a fillet, and then have to delete everything, rebuild the curves and so forth and do it all over.

Rebuilding to a tolerance and rebuilding joined curves are both bad ideas. You can experiment to see why I say that. Sometimes reducing the default mesh angle from 10 degrees to 1 degrees can help correct graphical display glitches.

All of the above is my own experiences with MoI over the last few months.

Anthony