Sweep sketch black PartBody

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dom11990
Posts: 7
Joined: Sat Oct 02, 2021 7:21 am

Sweep sketch black PartBody

Post by dom11990 »

Hi all,

I'm a very new to FreeCAD so I apologize if you this question is very basic.. I'm trying to cut space for an electrical gasket in my housing. I've had some good success with it in the past, however, on my latest attempt it is turning my Part black. I have no idea why since the same process worked for other sweeps! Can anyone point out what I am doing wrong?


OS: Ubuntu 21.04 (XFCE/xubuntu)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Python version: 3.9.2
Qt version: 5.15.2
Coin version: 4.0.0
OCC version: 7.5.1
Locale: English/United States (en_US)
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Housing.FCStd
(459.18 KiB) Downloaded 37 times
GeneFC
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Location: Punta Gorda, FL

Re: Sweep sketch black PartBody

Post by GeneFC »

The corners are too sharp for the swept shape. If you look closely at the corners you can see overlap of the edges.

I tried different corner styles without success. I think you will need to either modify the path or change the swept shape.

When I increased the "gasket fillet" a bit the body regained its normal coloration.

Gene
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Shalmeneser
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Location: Fr

Re: Sweep sketch black PartBody

Post by Shalmeneser »

Sketch Gasket Trench Center : try 0.6 radius

(Sketch Gasket Trench Center Bit : constraint 5+11+15+5-line+6-line = Sketcher_ConstrainSymmetric)
dom11990
Posts: 7
Joined: Sat Oct 02, 2021 7:21 am

Re: Sweep sketch black PartBody

Post by dom11990 »

Thanks! I guess I didn't know why it should be a problem if the radius is too tight. Maybe I'm also going about this the wrong way- Is there a smarter way of creating these kind of gaskets? I'm trying to make the resulting structure manufacturable with an aluminum CNC.

cheers
dom
chrisb
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Re: Sweep sketch black PartBody

Post by chrisb »

Perhaps this helps explaining self intersections.
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fcbook.pdf
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A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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Shalmeneser
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Re: Sweep sketch black PartBody

Post by Shalmeneser »

chrisb wrote: Mon Oct 18, 2021 11:00 am ...
Just a teaser by ChrisB. :twisted:
GeneFC
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Re: Sweep sketch black PartBody

Post by GeneFC »

dom11990 wrote: Mon Oct 18, 2021 8:20 am Thanks! I guess I didn't know why it should be a problem if the radius is too tight.
Try drawing it out by hand while keeping both the shape and the path exactly as drawn. You will find it is impossible to avoid an overlap. Obviously is is possible to distort the shape to avoid an overlap, but that is a much more complex operation.

Additionally, if you are really trying to fit a length of premade gasket shape into that groove you will find the same sort of interference. Depending on the material it may squeeze into the groove or not.

Gene
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