Unwanted residual after substraction

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Tankgunner
Posts: 3
Joined: Tue Aug 09, 2022 9:10 am

Unwanted residual after substraction

Post by Tankgunner »

Hello everyone,

I'm new to FreeCAD, and experiencing this problem. A face from additive helix remains floating in the body, so Part_CheckGeometry reports error
error.JPG
error.JPG (119.41 KiB) Viewed 671 times
The mistake can be traced up to the first step after Additive Helix (Cylinder), when I'm trying to fill the gaps, to get a solid body with threaded outer shape.
I wonder how to fix it. I can trace the badly located face, but can't remove it manually.


Many thanks to answer.

The file is located here (4mb) https://drive.google.com/file/d/1yADuid ... sp=sharing



UPDATE. I solved it myself. Draft workbench -> Draft_downgrade -> delete face -> Draft_Upgrade -> [the new Shell is fine with no errors ]-> Part Convert to Solid

Hope it will help someone.

If there are ways to evade such faults with helixes or easier solutions for errors, I will still be glad to read and try.

Alexey (Tankgunner)



Code: Select all

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.29177 (Git)
Build type: Release
Branch: releases/FreeCAD-0-20
Hash: 68e337670e227889217652ddac593c93b5e8dc94
Python 3.8.10, Qt 5.15.2, Coin 4.0.1, Vtk 8.2.0, OCC 7.6.2
Locale: Russian/Russia (ru_RU)
Installed mods: 
  * fasteners 0.3.50
  * Manipulator 1.4.9
  * ThreadProfile 1.81.0
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Shalmeneser
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Location: Fr

Re: Unwanted residual after substraction

Post by Shalmeneser »

The AdditiveHelix and 1st Cylinder should not be coplanar (17 mm in the two steps, try 16.999 for one).
chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: Unwanted residual after substraction

Post by chrisb »

You should avoid coplanar faces and seams. Your model shows errors already for the first added cylinder. They vanish if I reduce the cylinder's radius to 16mm. I didn't continue, because the model broke due to topological naming problems, caused by sketches attached to generated faces.

Edit: Shalmeneser found the culprit faster :) .
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: Unwanted residual after substraction

Post by Shalmeneser »

My model is just for ideas :idea:
Attachments
CapPasCap_SHALMv2.FCStd
(776.96 KiB) Downloaded 8 times
Capture d’écran 2022-08-09 152250.jpg
Capture d’écran 2022-08-09 152250.jpg (60.77 KiB) Viewed 560 times
Tankgunner
Posts: 3
Joined: Tue Aug 09, 2022 9:10 am

Re: Unwanted residual after substraction

Post by Tankgunner »

Chrisb, Shalmeneser, thank you! :D
Coplanar issue seems to be useful.

Best regards,
Alexey (Tankgunner)
chrisb
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Re: Unwanted residual after substraction

Post by chrisb »

There is the Thread for Screw Tutorial, where you should look at the "Tips for success" for more pitfalls to avoid.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Tankgunner
Posts: 3
Joined: Tue Aug 09, 2022 9:10 am

Re: Unwanted residual after substraction

Post by Tankgunner »

chrisb wrote: Tue Aug 09, 2022 4:47 pm There is the Thread for Screw Tutorial, where you should look at the "Tips for success" for more pitfalls to avoid.
Thank you chrisb! I've studied through it before, seems have to re-read again.

Alexey (Tankgunner)
chrisb
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Re: Unwanted residual after substraction

Post by chrisb »

Tankgunner wrote: Wed Aug 10, 2022 3:29 am Thank you chrisb! I've studied through it before, seems have to re-read again.
In short it is:
- most important: no self intersections, i.e. no overlap of the helix turns!!
- no coplanar faces
- no helix start on a seam

There are some more:
- refining a helix can lead to problems in later steps
- if a helix looks distorted, it can help to change the segment length
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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