Create chamfer between two spheres

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newbiecad
Posts: 5
Joined: Thu Apr 22, 2021 1:27 am

Create chamfer between two spheres

Post by newbiecad »

Hi friends!
I decided to use freecad instead of autocad. But from the start I have the impression that I'm at a dead end. :lol:
I want to Create an inverted chamfer between two spheres (or Make Fillet between two objects)
Is this possible or impossible with freecad?
Like in the attached photo
Image
thanks in advance!
jmaustpc
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Location: Australia

Re: Create chamfer between two spheres

Post by jmaustpc »

newbiecad wrote: Thu Apr 22, 2021 1:52 am Is this possible or impossible with freecad?
Yes, one simple approach could be just with a rotation in PartDesign workbench something like this, note that I have constrained the sketch based on the values in the green coloured cells of the spreadsheet via expressions. So you can change this file by just editing those values in the spreadsheet cells.

here is the demo file
twospheresdemo.FCStd
(11.26 KiB) Downloaded 11 times
here is a screen shot
Screenshot_20210422_134146.png
Screenshot_20210422_134146.png (161.11 KiB) Viewed 724 times
OS: Ubuntu 20.04.2 LTS (KDE/plasma)

and the spreadsheet
Screenshot_20210422_134528.png
Screenshot_20210422_134528.png (110.21 KiB) Viewed 724 times
Jim


Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19. Stable PPA
Build type: Release
Branch: unknown
Hash: 9e3b630bbfb6807e93eeffb655e6c20f218644fc
Python version: 3.8.5
Qt version: 5.12.8
Coin version: 4.0.0
OCC version: 7.5.1
Locale: English/Australia (en_AU)
chrisb
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Re: Create chamfer between two spheres

Post by chrisb »

SnipScreenshot-979641.png
SnipScreenshot-979641.png (18.74 KiB) Viewed 709 times
Although fillets are not the most stable tool in FreeCAD, it is well possible to use the system fillets:
Attachments
filletSpheres.FCStd
(8.52 KiB) Downloaded 13 times
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
newbiecad
Posts: 5
Joined: Thu Apr 22, 2021 1:27 am

Re: Create chamfer between two spheres

Post by newbiecad »

@jmaustpc :shock:
I've been struggling for two days!
I am on version 0.18 (because my pc is in 32bits I cannot migrate to version 0.19)
I tried to open your file with version 0.18, it doesn't work for the sketch.

You used a revolution with a sketch on the same plane and same axis (something I already did in draft), but I want to be able to do it on two planes (an offset of 20 mm on the Y axis for example ) that's why I tried everything with two bodysuits without succeeding yet!

Do you have any idea how to do it? A thread between two bodies in insertion is not possible?

I am ashamed of myself! I have to design a small simple part with 4 balls (side by side) aligned on the X axis but 2 central balls are slightly offset to the Y axis.
Finally, Between these balls I have to make a fillet for it to be beautiful :)

Many thanks!
newbiecad
Posts: 5
Joined: Thu Apr 22, 2021 1:27 am

Re: Create chamfer between two spheres

Post by newbiecad »

chrisb wrote: Thu Apr 22, 2021 4:15 am SnipScreenshot-979641.pngAlthough fillets are not the most stable tool in FreeCAD, it is well possible to use the system fillets:
Dear @chrisb
Thanks for your help!
Herewith my freecad file after editing yours. Look at the bug!
I didn't understand why the fillet rendering is not identical between ball 1 and 2 and that between ball 3 and 4!
Is this a freecad bug or a bug from me?

Then I noticed that some spheres are empty and others are full after the fusion! yet they are pasted copies of the same sphere.
I'm going to pull my hair !!! :twisted:
FilletSpheres Bug.png
FilletSpheres Bug.png (55.86 KiB) Viewed 698 times
filletSpheresBug.FCStd
(80.21 KiB) Downloaded 11 times
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papyblaise
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Re: Create chamfer between two spheres

Post by papyblaise »

Put your hair back on your head and erase "fillet
In Fusion you do "Refine = True"
and make the fillets one after the other, choosing the "Wireframe" display mode to more easily select the edges
Attachments
boulier.PNG
boulier.PNG (74.31 KiB) Viewed 684 times
newbiecad
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Joined: Thu Apr 22, 2021 1:27 am

Re: Create chamfer between two spheres

Post by newbiecad »

papyblaise wrote: Thu Apr 22, 2021 6:29 am Put your hair back on your head and erase "fillet
In Fusion you do "Refine = True"
and make the fillets one after the other, choosing the "Wireframe" display mode to more easily select the edges
Dear papyblaise thank you for your help!
With version 0.18 this only works for two levels of Fillet(i.e. it accepts the first Fillet then the 2nd but at the third it doesn't apply and makes a question mark!)
If you are another solution that will help me greatly!
In any case, it's a bug to be pointed out because if it's necessary to apply this approach it's useless to propose the multiple selection of the edges. Is that the logic? :?:
chrisb
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Re: Create chamfer between two spheres

Post by chrisb »

Upgrade to 0.19 is probably easier than to keep the forum regulars busy, searching a solution for a two years old obsolete version, which is more than 8000 improvements behind. It is probably a so called coplanar issue, which can be avoided by slightly raising or lowering one of the middle spheres.
Using the Refine option from papyblaise I can fillet in one go.

OS: macOS 10.16
Word size of FreeCAD: 64-bit
Version: 0.20.24720 (Git)
Build type: Release
Branch: master
Hash: 8b0c58d1b45017ad42bf0fa8f827f1cf22a398e7
Python version: 3.9.2
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.1
Locale: C/Default (C)
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
newbiecad
Posts: 5
Joined: Thu Apr 22, 2021 1:27 am

Re: Create chamfer between two spheres

Post by newbiecad »

chrisb wrote: Fri Apr 23, 2021 5:50 am Upgrade to 0.19 is probably easier than to keep the forum regulars busy, searching a solution for a two years old obsolete version, which is more than 8000 improvements behind. It is probably a so called coplanar issue, which can be avoided by slightly raising or lowering one of the middle spheres.
Using the Refine option from papyblaise I can fillet in one go.

OS: macOS 10.16
Word size of FreeCAD: 64-bit
Version: 0.20.24720 (Git)
Build type: Release
Branch: master
Hash: 8b0c58d1b45017ad42bf0fa8f827f1cf22a398e7
Python version: 3.9.2
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.1
Locale: C/Default (C)
Dear @chirsb
I would have done it already if version 0.19 exists in 32bits!
But I can't change my windows version to 64bits with all my software, licenses and projects!
If the community could do a compilation for 32bits, that would be great!

In any case thank you, it allowed me not to go round and round without knowing the cause!
chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: Create chamfer between two spheres

Post by chrisb »

Sorry, I hadn't re-read through the previous posts, where you had mentioned the 32-bit system. It is better to add the full FreeCAD infos, we forum regulars recognize it at a glance then. (I admit: I might have missed the 32 bits anyway.)
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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