Surface Holes and Artifacts

Rhino v4

Surface gets mirrored and solid created. How to eliminate artifacts and file hole in surface so that all is nice and smooth?


surfacehole.3dm (133.0 KB)


File will be updated soon



Is easy when both tubes are same OD like you use in your demo.

Problem is, top tube is 53mm OD and bottom tube is 44mm OD. Top radius 12mm. Bottom fillet 12mm

view from bottom looking up at 44mm tube. See how 53mm tube has to connect.

Remove the ‘funny’ part, delete. Dupedge the two lower edges, join. Then use sweep2 with the joined edge, upper edge, tiny right end edge and long left edge. Join to the assembly.

It’s not ‘beautiful’ but there’s no naked edges except for the planar ‘divide’.


surfaceholeck.3dm (223.7 KB)

You need a couple more fillets (FilletSrf) - see the attached file - to bridge the existing fillets to the tubes.

surfacehole_PG.3dm (115.3 KB)


It is possible to make this blend G2 if you’re willing to rebuild the main tubes to a higher degree.

If you’re looking for precise 12mm radii then here is a version with that. Of course, the fillet is tangent and not as smooth as you’d get if you could have a curvature continuous blend… surfacehole_SC.3dm (116.8 KB)

ChrisK and Pascal

I can’t open your files with Rhino v4

Rhino v4

Here is construction more representative as to how the part will actually be constructed. Two pieces of steel tubing and a flat piece of sheet metal bent (blue piece) with a 22mm radius to match the 44mm tube. I can’t get _VariableFilletSrf to work correctly. Fillet needs to taper from zero to 12mm radius.

VariableFilletSrf1.3dm (84.0 KB)

Here’s a V4 version.

surfacehole_PG_V4.3dm (110.5 KB)