> I made a new model (3dm file attached) and a close up of the 3D view shows a mis-match
> in the curved surface. It appears a portion of the outer surface extends into the cut-out area.
> This cutout was made by subtracting an extruded closed outline from the base solid.

Hi Ed, I haven't had a chance to examine your file yet (I'll be out on vacation for another week), but this type of thing can often be caused by a slight loop (like a type of little curly-cue) in the original curve that was extruded.

Another thing that that can cause problems is if the original curve has some of its control points stacked up exactly on top of one another. You can check this kind of problem by selecting the curve and use Edit/Show pts to display its control points. Any spot with multiple control points stacked up on top of one another will display with a red box around it.


> Can this type of issue be repaired, or do I start over?

It is possible to do a kind of salvage operation to repair this kind of thing, but it is somewhat involved. If your model was made up of surfaces more complex than an extrusion, then it would save time to try and repair it, but with an extrusion that is pretty straight-forward to reconstruct so I'd say for this one I would generally start over.

If you do want some more information on how to repair and do the kind of low-level "salvage" operation, please see this tutorial for some more information on the techniques involved: http://moi3d.com/forum/index.php?webtag=MOI&msg=446.17

I would normally select your original curves and then use Edit/Show pts to look for any irregularities in the points (like stacked points), and also kind of zoom in on the area that has the problem to look for curly-cues or any problems in that area.


> My solids are made from 2D lines created in Corel Draw saved as EPS. Out of habit, I find Corel Draw fast and easy for creating 2D.

Sometimes there can be problems with the curves made in 2D illustration programs - some things like curly-cues or stacked up points don't really have much of an effect for fills and 2D stuff like that, but become much more of an issue when the shapes are punched into 3D solids, and then particularly when surfaces made from those curves are intersected with each other. The fillet command involves calculating the intersection of surfaces behind the scenes in order to calculate its result.


Normally I would try to examine your curves to give you more specific advice to your situation, but if you need that it will have to wait until I return... Hope this helps some though.

- Michael