Curves workbench

Have some feature requests, feedback, cool stuff to share, or want to know where FreeCAD is going? This is the place.
User avatar
Chris_G
Posts: 864
Joined: Tue Dec 31, 2013 4:10 pm
Location: France
Contact:

Re: Curves workbench

Postby Chris_G » Tue Aug 07, 2018 4:03 pm

UR_ wrote:
Tue Aug 07, 2018 3:17 pm
I've no clue what's going on :(
At the beginning of your file, the Base Helix is made of 2 edges.
This leads to a Section_pitch_curve that cannot be joined into a single curve.
I used JoinCurve on the base helix, and so I was able to join Section_pitch_curve into 1 single curve.
Also, if you attach your thread profile sketch to the upper end of the curve, you can use a standard attachment mode.
Spax-2.png
Spax-2.png (65.26 KiB) Viewed 509 times
Attachments
Spax-2.FCStd
(81.25 KiB) Downloaded 5 times
UR_
Posts: 632
Joined: Tue Jan 03, 2017 8:42 pm

Re: Curves workbench

Postby UR_ » Tue Aug 07, 2018 5:10 pm

Chris_G wrote:
Tue Aug 07, 2018 4:03 pm
Also, if you attach your thread profile sketch to the upper end of the curve, you can use a standard attachment mode.
I think that's only why "Revolve screw tip" has a nearly vertical tangent at the upper edge.

Changing "Sketch screw tip" will reveal this:

2018-08-07 19_03_26-FreeCAD 0.18.png
2018-08-07 19_03_26-FreeCAD 0.18.png (9.04 KiB) Viewed 491 times

But that's another question :)
User avatar
Chris_G
Posts: 864
Joined: Tue Dec 31, 2013 4:10 pm
Location: France
Contact:

Re: Curves workbench

Postby Chris_G » Tue Aug 07, 2018 8:44 pm

UR_ wrote:
Tue Aug 07, 2018 5:10 pm
I think that's only why "Revolve screw tip" has a nearly vertical tangent at the upper edge.

Changing "Sketch screw tip" will reveal this:
OK, I see what you mean : you're right.
One possible solution is to duplicate CurveOnSurface and to switch it to output the Binormal face.
This way, you have the 3 perfect vertexes to attach the sketch as OXY
3_vertexes.jpeg
3_vertexes.jpeg (11.76 KiB) Viewed 468 times
Attachments
Spax-3.FCStd
(98.28 KiB) Downloaded 4 times
User avatar
bitacovir
Posts: 356
Joined: Sat Apr 19, 2014 6:23 am
Contact:

Re: Curves workbench

Postby bitacovir » Wed Aug 08, 2018 6:49 pm

Hi. it is my first time testing CurvesWB, but tools like BSplineCurve does not work at all and the 3D view is just get frozen.

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.14235 (Git)
Build type: Release
Branch: master
Hash: 7ad0c7f7f209c165370da2988ce51af70230c3bc
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/Australia (en_AU)
FreeCAD_2018-08-08_14-49-08.png
FreeCAD_2018-08-08_14-49-08.png (76.68 KiB) Viewed 409 times
::bitacovir::
===================================
One must be absolutely modern.
Arthur Rimbaud (A Season in Hell -1873)

My Blog
Mini Airflow Tunnel Project
User avatar
hammax
Posts: 589
Joined: Thu Jan 19, 2017 5:03 pm
Location: Ammersee

Re: Curves workbench

Postby hammax » Fri Aug 10, 2018 9:10 am

… Chris, sorry for hitting on the same wedge.
I tried to perform my ships propeller example with pure CurvesWB - and it works.
I had to split the profiles into a suction and a pressure half.
Full parametric, I also can control the blades' pitch by placement.
But... I am forced to use Draft-BSplines for leading and trailing edge - and they are NOT parametric.
The 3D-snapping potential (end point) is the desired but unfortunately not permanent feature.
If your feature for 3D-BSplines would work, maybe "some people" would be happy.
And a workflow description could be written or demonstrated (Normand's remark elsewhere).

Prop_CurvesWB.PNG
Prop_CurvesWB.PNG (72.86 KiB) Viewed 357 times
Attachments
S-Propeller_3.FCStd
FC.18.14235
(134.17 KiB) Downloaded 8 times
User avatar
Pauvres_honteux
Posts: 170
Joined: Sun Feb 16, 2014 12:05 am
Location: Far side of the moon

Re: Curves workbench

Postby Pauvres_honteux » Fri Aug 10, 2018 10:09 am

hammax wrote:
Fri Aug 10, 2018 9:10 am
…"some people" would be happy.
+1 (and count me in!)
freecad-heini-1
Posts: 4650
Joined: Tue Jan 07, 2014 11:10 am
Contact:

Re: Curves workbench

Postby freecad-heini-1 » Fri Aug 10, 2018 11:46 am

Pauvres_honteux wrote:
Fri Aug 10, 2018 10:09 am
hammax wrote:
Fri Aug 10, 2018 9:10 am
…"some people" would be happy.
+1 (and count me in!)
+1, me too ... hehe
User avatar
hammax
Posts: 589
Joined: Thu Jan 19, 2017 5:03 pm
Location: Ammersee

Re: Curves workbench

Postby hammax » Fri Aug 10, 2018 2:26 pm

… here is a complete Chris_G_ian CurvesWB example of parametric 3D-modeling of a blade halfprofile.
- starting with 2 pairs of parametric projection curves for LE and TE as 3D-BSplines
( a little bit scratching with the left hand on the right ear - not so easy)
- from this pair of 3D-curves a Ruled_Surface is derived,
- on the ruled surface there can be created some Profile_Planes by clicking at the wanted positions.
(look for the parameters position/height (0 .. 0,54 ..1,0) and direction x,y,z and adjust them - also right ear scratching,
Edit: after saving and reloading file, the planes get invisible (!) Visibility property doesn't work correct.
They can be activated again by editing e.g. x-value in properties.)
- on the profile planes the sketcher profiles can be generated - external and therefore parametric links to LE and TE are constrained,
- now with ruled surface and the 4 profile sketches the Sweep_2_rails is done,
- Sweep_2_rails at last can be converted to the Approximation_curve.
In the picture from bottom to top.
Prop_CurvesWB_2.PNG
Prop_CurvesWB_2.PNG (47.78 KiB) Viewed 294 times
Attachments
S-Propeller_4.FCStd
FC.18.14235
(127.91 KiB) Downloaded 7 times
Last edited by hammax on Sun Aug 12, 2018 11:03 am, edited 3 times in total.
UR_
Posts: 632
Joined: Tue Jan 03, 2017 8:42 pm

Re: Curves workbench

Postby UR_ » Fri Aug 10, 2018 3:30 pm

I have a little feature request:

Would something like this be hard to implement :?:

FreeCAD 0.18-000030.png
FreeCAD 0.18-000030.png (22.21 KiB) Viewed 283 times

If one will have lots of Sketches linked to lots of Profiles, they are really hard to maintain, especially if there are only small differences between the involved shapes.
freecad-heini-1
Posts: 4650
Joined: Tue Jan 07, 2014 11:10 am
Contact:

Re: Curves workbench

Postby freecad-heini-1 » Wed Aug 22, 2018 9:20 am

Hi Chris_G,
I have also a feature request, it concerns the possibility to snap to imported point cloud and create a bspline out of the points.

Please have a look at this thread:
https://forum.freecadweb.org/viewtopic. ... 12#p250612

That was hard work.
thschrader created a dwire face out of three points and used it as working plane.
No way to unhide points they are not on the same hight.

I wish to have a 3D spline to select and snap points in 3d view and create a bspline out of the points.

Best regards
Wilfried