## Curves workbench

Post here for help on using FreeCAD's graphical user interface (GUI).
Forum rules
and Helpful information
IMPORTANT: Please click here and read this first, before asking for help

Also, be nice to others! Read the FreeCAD code of conduct!
Chris_G
Posts: 1502
Joined: Tue Dec 31, 2013 4:10 pm
Location: France
Contact:

### 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: 1210
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.
https://forum.freecadweb.org/viewtopic. ... 63#p369150
Is there a way at all, to close sketches after building Gordon?

GordonClosed.PNG (61.98 KiB) Viewed 493 times
Attachments
GordonClosed.FCStd
(28.58 KiB) Downloaded 14 times
freecad-heini-1
Posts: 7363
Joined: Tue Jan 07, 2014 11:10 am
Contact:

### 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.
https://forum.freecadweb.org/viewtopic. ... 63#p369150
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
Contact:

### Re: Curves workbench

freecad-heini-1 wrote:
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
(13.03 KiB) Downloaded 22 times

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())

``````
freecad-heini-1
Posts: 7363
Joined: Tue Jan 07, 2014 11:10 am
Contact:

### Re: Curves workbench

Ich habe sowas gemeint:
curves_wb_sweep_on_two_rails_full_circle_2.FCStd
(39.81 KiB) Downloaded 19 times
Die Kreisbögen in den beiden Sketchen habe ich mit 1mm Spalt erzeugt, aber sie sollen geschlossen sein.
Chris_G
Posts: 1502
Joined: Tue Dec 31, 2013 4:10 pm
Location: France
Contact:

### Re: Curves workbench

Currently, Gordon surface doesn't work for closed surfaces.
I hope I can add this feature someday.
freecad-heini-1
Posts: 7363
Joined: Tue Jan 07, 2014 11:10 am
Contact:

### 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"
saw here :https://www.youtube.com/watch?v=6IkXAcz ... ex=16&t=0s
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
(21.15 KiB) Downloaded 14 times
Fillet003 is strange:
Surface_with_Fillet_example_fillet003.FCStd
(37.76 KiB) Downloaded 12 times
No problem with a solid:
Surface_with_Fillet_example_solid.FCStd
(67.92 KiB) Downloaded 14 times
The problem are the orange faces. It's needed to sew them:
orange_faces_sewed.png (34.21 KiB) Viewed 399 times
https://forum.freecadweb.org/viewtopic. ... 74#p239574
GlouGlou
Posts: 2632
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.
Hope It can help you.
Attachments
UpSideDown.JPG (33.3 KiB) Viewed 384 times
Surfaces.FCStd
(45.06 KiB) Downloaded 13 times
GlouGlou
Posts: 2632
Joined: Sun Apr 05, 2015 9:02 am
Location: La Rochelle, France

### Re: Curves workbench

here the exercise.
Attachments
zzz.FCStd
(274.26 KiB) Downloaded 30 times
Capture.JPG (33.85 KiB) Viewed 381 times
freecad-heini-1
Posts: 7363
Joined: Tue Jan 07, 2014 11:10 am
Contact:

### Re: Curves workbench

Thank you so much GlouGlou, the surface direction, good to know.