## Curves workbench

Post here for help on using FreeCAD's graphical user interface (GUI).
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Chris_G
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Joined: Tue Dec 31, 2013 4:10 pm
Location: France
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### Re: Curves workbench

Thanks Saso.
I wasn't sure it was a good solution either.
And I understand the drawbacks.
I will think about a better method.
hammax
Posts: 1184
Joined: Thu Jan 19, 2017 5:03 pm
Location: Ammersee

### Re: Curves workbench

… trying to build a "closed" (periodic?) Gordon surface there seems to be a minimalistic gap condition,
controlled by the tolerance value. If tolerance is 0,005 the gap must be greater (e.g. 0,01mm).
It is possible to make a closed shape by 2 Gordon surfaces.
Is there a way at all, to close sketches after building Gordon?

GordonClosed.PNG (61.98 KiB) Viewed 442 times
Attachments
GordonClosed.FCStd
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### Re: Curves workbench

hammax wrote:
Sun Feb 16, 2020 7:58 am
… trying to build a "closed" (periodic?) Gordon surface there seems to be a minimalistic gap condition,
controlled by the tolerance value. If tolerance is 0,005 the gap must be greater (e.g. 0,01mm).
It is possible to make a closed shape by 2 Gordon surfaces.
Is there a way at all, to close sketches after building Gordon?

GordonClosed.PNG
Exactly the same topic interested me, using a Sweep on two Rails. Which possibility is there to get a "closed" surface?
microelly2
Posts: 4690
Joined: Tue Nov 12, 2013 4:06 pm
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### Re: Curves workbench

Sun Feb 16, 2020 8:30 am
Exactly the same topic interested me, using a Sweep on two Rails. Which possibility is there to get a "closed" surface?
There are different ways to get a closed layout.
Here an example in 2D
close_curve.FCStd

Code: Select all

``````pts=[v.Point for v in App.ActiveDocument.Sketch.Shape.Wires[0].Vertexes]

bc=Part.BSplineCurve()
poles=pts
mults=[4,1,1,1,4]
knots=range(len(mults))
bc.buildFromPolesMultsKnots(poles,mults,knots,False,3)
Part.show(bc.toShape())

bc=Part.BSplineCurve()
poles=pts+[pts[0]]
mults=[4,1,1,1,1,4]
knots=range(len(mults))
bc.buildFromPolesMultsKnots(poles,mults,knots,False,3)
Part.show(bc.toShape())

bc=Part.BSplineCurve()
poles=pts+[pts[0]]
mults=[1,1,1,1,1,1,1,1,1]
knots=range(len(mults))
bc.buildFromPolesMultsKnots(poles,mults,knots,True,3)
Part.show(bc.toShape())

bc=Part.BSplineCurve()
poles=pts+[pts[0],pts[0]]
mults=[1,1,1,1,1,1,1,1,1,1]
knots=range(len(mults))
bc.buildFromPolesMultsKnots(poles,mults,knots,True,3)
Part.show(bc.toShape())

bc=Part.BSplineCurve()
poles=pts
mults=[1,1,1,1,1,1,1,1]
knots=range(len(mults))
bc.buildFromPolesMultsKnots(poles,mults,knots,True,3)
Part.show(bc.toShape())

``````
Posts: 7224
Joined: Tue Jan 07, 2014 11:10 am
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### Re: Curves workbench

Ich habe sowas gemeint:
curves_wb_sweep_on_two_rails_full_circle_2.FCStd
Die Kreisbögen in den beiden Sketchen habe ich mit 1mm Spalt erzeugt, aber sie sollen geschlossen sein.
Chris_G
Posts: 1428
Joined: Tue Dec 31, 2013 4:10 pm
Location: France
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### Re: Curves workbench

Currently, Gordon surface doesn't work for closed surfaces.
I hope I can add this feature someday.
Posts: 7224
Joined: Tue Jan 07, 2014 11:10 am
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### Re: Curves workbench

GlouGlou wrote:
Fri Feb 07, 2020 8:33 pm
A suggested tool: select the two yellow edges, then make a tangent arc. Just need the radius.
Could be called "TangentArc"
Hello GlouGlou and others,
I tried to follow the example in Freecad. The faces, Connect and Split / Slice are good, but as soon as you start rounding the faces, Freecad behaves strange. It trims away surfaces in places that should be preserved. Who can show how to round these surfaces with R10 to R30mm?

Many greetings
Wilfried
Surface_with_Fillet_example.FCStd
Fillet003 is strange:
Surface_with_Fillet_example_fillet003.FCStd
No problem with a solid:
Surface_with_Fillet_example_solid.FCStd
The problem are the orange faces. It's needed to sew them:
orange_faces_sewed.png (34.21 KiB) Viewed 348 times
GlouGlou
Posts: 2418
Joined: Sun Apr 05, 2015 9:02 am
Location: La Rochelle, France

### Re: Curves workbench

Sometimes Part tools carry out surfaces upside downed . But We are not able to see them until make an offset3D.
By using "reverse shapes" (PartWb) we can give the right direction for all faces.
Then Connect can be refined. and Fillet works better.
Attachments
UpSideDown.JPG (33.3 KiB) Viewed 333 times
Surfaces.FCStd
GlouGlou
Posts: 2418
Joined: Sun Apr 05, 2015 9:02 am
Location: La Rochelle, France

### Re: Curves workbench

here the exercise.
Attachments
zzz.FCStd