[Solved] I can't generate a 3D pocket toolpath for half spheres

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pathfinder
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Joined: Mon Oct 04, 2021 10:27 am

[Solved] I can't generate a 3D pocket toolpath for half spheres

Post by pathfinder »

Hello,

I can't generate a 3D pocket toolpath for half spheres and I wonder why.

I have a model that I'm working on, on which some, but not all pockets generated viable toolpaths. Some pockets were ignored, in others, just the top layer was generated, in some, in between layers were missing, others generated a toolpath on the bottom of the object, so straight through the object; so basically I had every possible bug in one operation. There is no functional difference between the pockets, they are all part of a linear pattern.

To investigate, I rebuilt the shape, but simpler. It is the file I attached. I can't generate any 3D pocket toolpaths on this one. I played around with cut patterns, different tools, different step downs, stepovers and so on. No dice.

Does anybody know why, and how I can work around these issues?

Code: Select all

OS: Arch Linux (XFCE/xfce)
Word size of FreeCAD: 64-bit
Version: 0.20.28810 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 6f5a5a2)
Hash: 6f5a5a2019c586db63650713de860d3e810739d4
Python 3.9.12, Qt 5.12.9, Coin 4.0.0, OCC 7.5.3
Locale: English/United States (en_US)

TIA

Edit:

I did try one more time; this is what happens when I select none of the pocket faces:

Image

As you can see, it does something, but not all pockets are cut properly.

Both 3D surface and Waterline work as they are intended, but have their own limitations.
Attachments
holes.FCStd
(53.34 KiB) Downloaded 17 times
Last edited by pathfinder on Mon May 16, 2022 1:20 am, edited 1 time in total.
chrisb
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Re: I can't generate a 3D pocket toolpath for half spheres

Post by chrisb »

pathfinder wrote: Sun May 15, 2022 5:46 pm and how I can work around these issues?
Did you try 3D Surface?
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chrisb
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Re: I can't generate a 3D pocket toolpath for half spheres

Post by chrisb »

It seems to be a coplanar issue. If I lift the sketches of the grooves by 0.1mm it works as expected:
Attachments
holes_cb.FCStd
(149.95 KiB) Downloaded 18 times
SnipScreenshot-99a717.png
SnipScreenshot-99a717.png (42.46 KiB) Viewed 802 times
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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pathfinder
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Re: I can't generate a 3D pocket toolpath for half spheres

Post by pathfinder »

chrisb wrote: Sun May 15, 2022 10:45 pm It seems to be a coplanar issue.
Yup, solved, thanks.

Booleans being booleans I guess. I need to be more mindful of that.

Btw. 3D surface worked fine, as did waterline.

Now I need to find out how to create an offset on the pocket similar to BoundaryAdjustment from 3D surface. There is an offset you can set, but it doesn't seem to work in the z-direction.
chrisb
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Re: I can't generate a 3D pocket toolpath for half spheres

Post by chrisb »

pathfinder wrote: Mon May 16, 2022 1:19 am Now I need to find out how to create an offset on the pocket similar to BoundaryAdjustment from 3D surface. There is an offset you can set, but it doesn't seem to work in the z-direction.
An old mechanic told me what he does in such cases on a real machine: Fool it by pretending that you have a different tool. In your case it has to be a little bit longer.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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pathfinder
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Re: I can't generate a 3D pocket toolpath for half spheres

Post by pathfinder »

chrisb wrote: Mon May 16, 2022 1:24 am
pathfinder wrote: Mon May 16, 2022 1:19 am Now I need to find out how to create an offset on the pocket similar to BoundaryAdjustment from 3D surface. There is an offset you can set, but it doesn't seem to work in the z-direction.
An old mechanic told me what he does in such cases on a real machine: Fool it by pretending that you have a different tool. In your case it has to be a little bit longer.
-___- My brain sometimes… As if I didn't do this exact thing last time. Thanks for the nudge, I guess.
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