Error: Could not process surface!

[Swiss]

Hi guys,
I had some trouble importing a STEP file. Now, when I try to do planar finishing, or z-leveling, it tells me about 10 times "Error : could not process surface!". I have to click "OK" each time. Then it goes ahead and generates the toolpath.

Is there any way to identify which surfaces are causing the problem, and fix them?

thanks

Swiss

[HuFlungDung]

About all you can do is visually inspect the surfaces. Sometimes you might see an actual missing surface in some area. The problem is a problem with the model, not the toolpath. You might get away with leaving the model 'broken', if you simulate it and it looks ok, and shows no toolpath going through the model somewhere.

This type of error is often due to a construction problem, such as creating tiny sliver surfaces when extruding a part from an internal offset of a pre-existing good chain, or if the chain had bad trim to begin with, same thing.

It might also occur when a filleting operation has been performed too close to an existing edge, forcing the filletted surface to try to fill a zero width space at some point. Often, a different sequence of operations in constructing the model (filleting first, then trimming off some excess stock) can make a sound model.

If you post your file here, or register and post on OneCNC's forum (for more privacy), someone can take a look at the model....maybe find a fix for the model.

[Swiss]

Thanks Hu'

Yes, I agree. It's definitely a problem with the model, not the toolpath.

I always carefully inspect models when I import them to check for problems. This time, I had some missing surfaces, which I replaced, but I could not find any other visible problems.

Please find attached a .ZIP file containing my model. If you can help me with this, that would be great!

Do you know of any way to pinpoint exactly those surfaces causing the error?

thanks again

Swiss

[HuFlungDung]

Can you stand one bad surface? See my attached file.

From what I could see, the ball on the left side had a few duplicate surfaces in it. Best fix there is to break that area into surfaces, since it was kind of merged into an "open solid" which is kind of hard to work with.

The outer surround and the right ball are okay so just blank those.

Then on the left ball, begin merging the surfaces again, a few at a time. When you do this exercise, you will see at some point, that a surface is a duplicate, giving a mottled appearance at the moment of selection. You can delete that one, then select again, then try the merge. In piecemeal fashion, you can rebuild the model into something containing only one surface everywhere.

Save often after each successful merge. If you get any messages about "we sewed together as much as possible", go back with undo, and try a different selection to try to work around the problem area that won't merge without generating a sewing message. A "sewn solid" is never truly closed.

I don't know exactly why my attempt did not give a good solid. However, there was a thin sliver of an arc surface on the underside of the ball, that OneCNC did not want to merge with the rest, and so I deleted it. Maybe I should have searched farther into where that came from, and what kind of a hole it left. The error was to the effect that by selecting that arc sliver and the rest of the model, that I had not selected two objects so there was nothing to merge!

[Swiss]

Brilliant!

Thanks Hu, you've solved it! I tried planar finishing on your file, and it gave one "Could not process surface" and one "surface contains bad data". So I tried deleting a few surfaces, and the messages stopped. So I undo'd, and the messages didn't seem to come back. Strange, but the problem seems to be sorted.

thanks again

Swiss