Corner fillet fix

How to fix this cap?
I tried several surface tools but I couldn’t get good results…

FILLET FIX.3dm (235.5 KB)

Other corners are made with solidfillet…

Thanks :slight_smile:

You can either extend the three adjacent surfaces until they all intersect each other, and then try to trim them. You might need to untrim the flatter surface of the three, instead of extending it.

Alternatively, you could try NetworkSrf.

Thanks diff-arch, but no help of these.

What do you mean.

Here’s how it looks after using NetworkSrf:

This is what I get…

I think that sucks, but…

Maybe I don’t know all the command settings, but the only way I got good result is to div edges,
extract isocurves and blend those together.
Then use _NetworkSrf.

Lets say I have hundreds of broken fillets, will take a lot of time to fix these…
Very often I send iges to my colleague and he makes the fillets in solidworks…

I think Rhino should publish any new features in R8. I think the only new thing should be to modify the fillet to work perfect… I’ve been using Rhino 15 years, and still fillets are big pain in the…

Different approach with a clean starting surface

FILLET FIX.3dm (385.5 KB)

Hi Martin!
Looks good, but these are made in parametric softwares and then sent to us.
And also there is now fillet where it should not be. I mean the horizontal and vertical surface edge…
It would be insane job to model everything again… Almost everytime surfaces are very good in quality…
I just need to fillet these corners because sometimes milling sharp corners are not “possible”…

BR: Wagner

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The first method I mentioned above works also, but instead of trimming the bigger, untrimmed surface, I simply got rid of it. It was beyond saving. I rebuilt it with a two-rail-sweep of duplicated boundary edge curves.

FILLET FIX 2.3dm (2.6 MB)

I understand your problem.


I think people expect too much.

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blend surface and match multiple.

sweep1 actually also produces a good result but the surface continuity is not very accurate, if that is important for milling at all at this stage.

FILLET FIXx.3dm (35.6 KB)

I tried sweep1 also earlier and now again.
My result is not so good…

I got same kind of results with many surface tools (blend surface, patch, sweep 1/2, EdgeSrf, NetworkSrf…
Yes, I can maybe live with that (until I export solid to manufacturer) but I think it is not high quality surface. Rhino is awesome software and I really love it but it should not be so difficult to make good fillets… It’s not all about this exact fillet (because there is hundreds of more same kind of), maybe I just want to hear if there is already a tool, or if it is impossible to develope easy high quality fillets…

Sorry my bad english :frowning:

did you try blend surface as in the example posted above?

So what’s wrong with this?

FILLET FIX.3dm (231.7 KB)

Hi Wagner -

If you are dependent on fixing a lot of these, you might want to take a look at XNURBS.

This is the part I wonder about. Did that surface that you are trying to create in Rhino not import correctly from that other application? If so, that might be something that could be fixed.


Martin: That is possible option (without third curved edge). and yes, I can do it here like that.
BUT, the case is not this exact corner.
like I tried to say, I think it is weird that there is not (what I know with 15y Rhino experience) tool to make good quality fillet/patch/cap from 3 curved edges like in the example without a lot of extra work.

Encephalon: Yes I tried blendsrf and It made best result. Anyway it wanted to move lower edge.
Sample edge was made with blendcrv and then cut.

Wim: I’ll check xnurbs, thanks for the tip. Anyway it is not the case, rhino fillets are awful…
Yes, imported surfaces are very good in quality and imported correct, no bad surfaces or something like that…

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Hi Wagner -

But does that mean that this surface was somehow missing in the original file?

Hi Wim!

No, it was not missing. All the surfaces were good quality. Beacause of 3-axis milling I have to make fillets to the corners and Rhino s&%ks when talking about fillets… 2 of 3 I have to do manually (Corners/joints).

i would do:
_loft with option start / end tangent
_changeDegree 5/5
_matchSrf (position for the missing edge - refine yes)
_matchSrf (tangent for all edges refine yes)

FILLET FIX_tp.3dm (220.7 KB)

i would recommend to do an additional minimal fillet in the concave edge (red)
this will allow a more proper solution and avoid a triangular surface.

if you re really in a hurry, and it is just because the millbit should be stop to step into …
we are talking about a 0.5x0.5x1.0 mm surface and not a detail of a car…
in real live, we will not see the difference between a perfect surface (that small) and quite _patch - i doubt that the difference can be produced or is within production tolerance.
kind regards

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Hi Tom!
Thank you for your tips, I didn’t know you can make curved lofts… :slight_smile:
If not extramely nesessary, I don’t want to use fillet there (red) because of the cam to avoid problems (I’m not professional of the cam)…
Lets say In my one ( I have several parts) part has 200 of these. After solid piece, I have to offset and get solid part again. If there is not good surfaces, I have to do 200 corners again… :frowning: Very frustrating…