I get a lot of these 'calculation failed' errors on simple geometry and it's frustrating because I end up having to spend a lot of time figuring out workaround. I downloaded a demo of Rhino a while back and it was able to handle most of these situations. Is there some method for figuring out what's causing the failure?

Post your 3Dm for maybe more advices! ;)

Here's an example from the model I'm working on. I don't know if the file is attached. This seems like a very straightforward piece of geometry, but it won't fillet or chamfer the shown selected edges.

Hi MrChristopher3D

Running Naked Edge script, there are two short Naked Edges, 0.03 inches, "on top of" each other.

The geometry there must be a problem?

- Brian

Hi Christopher3D, MoI's filleter doesn't like it if you have fragmented coplanar faces.

Also the size of your object is getting on the small side which can also mess things up somewhat as well.

Here's a version of your object where I made just one large face for the top plane instead of having multiple coplanar fragments and I also scaled it up by 10x in size and it fillets ok now:



- Michael

Great thanks, I'll keep those two points in mind for future projects.

Maybe like this ? :)
Another solution without resize...then kill that you don't want...

Here's another area, I extracted this from another part of the model, and these edges refuse to fillet.

Hi MrChristopher3D.

All fillets are made 0.06 units. And this is the maximum to succeed on the first attempt, for the upper parts of this model.

Hi MrChristopher3D, this will fillet if you select the entire object to fillet instead of only some edges:



It's more difficult to fillet only some edges coming off of a juncture point and not all edges. When you fillet all edges it will be able to construct a corner juncture patch in between them instead of needing to extend and intersect the fillets against each other directly which is more difficult.

If you frequently need to fillet only some edges coming off of a common point and not all you should probably plan to export out to another CAD program with a more developed fillet engine in it (for example OnShape, Fusion 360) to do some of those that MoI can't handle.

Another thing that makes this one more difficult to fillet is that the top surfaces are from a previous small radius fillet. It's generally best to put on all fillets going through the same area at the same time instead of in separate passes, so that corner juncture patches can be made.

- Michael