Path module fails to generate path on my parts

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Konstantin
Posts: 261
Joined: Wed Jul 23, 2014 10:10 am

Path module fails to generate path on my parts

Post by Konstantin »

Hello, it's me again, again with my guitar.
This time I am trying Path workbench. First I tried it with simple cubes and holes, it worked with no visual problems, but when I tried my guitar body, it failed, unfortunately.

Most interesting result I get with "Profile based on faces". Then I see the path is wrapping here and there while I'm adding faces. very strange behaviour.

I know, Path workbench is in development, and so on, but maybe you need an example of complex shape? Here it is :)

OS: "Manjaro Linux"
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9748 (Git)
Build type: Release
Branch: master
Hash: ad57478ab43308fce12035e07b4b9b2b4670774d
Python version: 2.7.13
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 6.9.1
Attachments
simplisied body.fcstd
(32.88 KiB) Downloaded 27 times
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Willem
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Posts: 1852
Joined: Fri Aug 12, 2016 3:27 pm
Location: Lisse, The Netherlands

Re: Path module fails to generate path on my parts

Post by Willem »

Study this tutorial https://www.youtube.com/watch?v=c4JUnB1AHdY. It give a lot of information about how to work with the path workbench. One major thing I understand from this tutorial is that you first define the tools you are going to use in the workshop and second the program will calculate the path for the CNC machining
Konstantin
Posts: 261
Joined: Wed Jul 23, 2014 10:10 am

Re: Path module fails to generate path on my parts

Post by Konstantin »

Yes, thank you, already watched this tutorial and read documentation before start experimenting. And I successfully made paths with simple parts like cube, cylinder and so on.

On my part, that I attached, it just fails to generate path with "Contour path for the base object" . With "Profile based on faces" tool it can generate path for the first selected face. But If I add more faces, then it stops on first one, or generates weird paths going from outside to inside, or looping on one face.

I would glad if someone who develops this workbench to look at my model.
Konstantin
Posts: 261
Joined: Wed Jul 23, 2014 10:10 am

Re: Path module fails to generate path on my parts

Post by Konstantin »

No, this is beautiful, I don't argue :)
Attachments
Screenshot_20170122_115914.png
Screenshot_20170122_115914.png (121.77 KiB) Viewed 1662 times
chrisb
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Posts: 53937
Joined: Tue Mar 17, 2015 9:14 am

Re: Path module fails to generate path on my parts

Post by chrisb »

It seems to be a regression problem:
I tried a profile based on edges:

It works here:
OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9586 (Git)
Build type: Release
Branch: (detached from 0e2cf2e)
Hash: 0e2cf2ebcaaa50723de608cf030af740cb6ad548
Python version: 2.7.13
Qt version: 4.8.7
Coin version: 3.1.3
OCC version: 7.0.0

Not working here:
OS: Ubuntu 14.04.5 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.9747 (Git)
Build type: None
Branch: master
Hash: f5c0f579cbd7ce668727f8835946e4e9abc0eec6
Python version: 2.7.6
Qt version: 4.8.6
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
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mario52
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Posts: 4673
Joined: Wed May 16, 2012 2:13 pm

Re: Path module fails to generate path on my parts

Post by mario52 »

hi
same see the post Spiralbohrer (ubuntu by freecad-heini-1 )

Image

mario
Maybe you need a special feature, go into Macros_recipes and Code_snippets, Topological_data_scripting.
My macros on Gist.github here complete macros Wiki and forum.
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bill
Posts: 376
Joined: Fri Jan 09, 2015 9:25 pm

Re: Path module fails to generate path on my parts

Post by bill »

gtar.png
gtar.png (14.57 KiB) Viewed 1643 times
Looks like it will at least generate a path for every segment.
But the problem might be (probably is) the model. It is over-constrained. This needs to be resolved before you go any further.
When you remove the constraint it recommends, you end up with 39 degrees of freedom. Probably not a good thing! :lol:
Konstantin
Posts: 261
Joined: Wed Jul 23, 2014 10:10 am

Re: Path module fails to generate path on my parts

Post by Konstantin »

I was thinking about it, but it is a dirty hack for this exact situation, not as it should be.
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bill
Posts: 376
Joined: Fri Jan 09, 2015 9:25 pm

Re: Path module fails to generate path on my parts

Post by bill »

Konstantin wrote:I was thinking about it, but it is a dirty hack for this exact situation, not as it should be.
Ya think !!!
No thinking to be done. Correct, this should be a one-click to a PATH. This is not a solution. Its simply shows that path(s) can be generated for each segment. You need to address your model before moving on to generate a path; SPECIFICALLY the "Sketch" (fix the OVER-CONSTRAINED situation).
before.png
before.png (21.32 KiB) Viewed 1629 times
after.png
after.png (15.31 KiB) Viewed 1629 times
bill, over and OUT!
Konstantin
Posts: 261
Joined: Wed Jul 23, 2014 10:10 am

Re: Path module fails to generate path on my parts

Post by Konstantin »

This "OVER-CONSTRAINING" Is appearing and disappearing in random places from version to version :) If you remove one constraint, next time it can become unsatisfied with another, I am tired of satisfying solver. :)

And in any case it doesn't fix the problem with Path module. As you can see, chrisb said, he succeed to build one with older version of FreeCAD.
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