[SOLVED] Issue with Sketching on curved Surface

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namezero111111
Posts: 14
Joined: Thu May 06, 2021 1:22 pm

[SOLVED] Issue with Sketching on curved Surface

Post by namezero111111 »

Dear folks,

I am trying to sketch onto a curved surface,but depending on the curved dimensions, some holes are filled in or not.
For example, changing the radius of one surface or another or the diameter of the holes.

It seems like there is some calculation with insufficient precision going on...
Could someone please enlighten me as to how to get this surface working?

I have attached a sample file
a.FCStd
(24.81 KiB) Downloaded 19 times
Capture.JPG
Capture.JPG (24.97 KiB) Viewed 605 times
Thanks!
Last edited by namezero111111 on Thu Sep 23, 2021 7:30 am, edited 1 time in total.
chrisb
Posts: 37831
Joined: Tue Mar 17, 2015 9:14 am

Re: Issue with Sketching on curved Surface

Post by chrisb »

What do you want to achieve? I did this with a Part slice:
SnipScreenshot-033ce0.png
SnipScreenshot-033ce0.png (17.63 KiB) Viewed 538 times
Attachments
a_cb.FCStd
(39.78 KiB) Downloaded 18 times
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namezero111111
Posts: 14
Joined: Thu May 06, 2021 1:22 pm

Re: Issue with Sketching on curved Surface

Post by namezero111111 »

Ok, I see. This is the result I need. The actual part is more complicated, but my problem was with this step.
I reproduced the slice because I wanted to know how to do it and deleted all the unused slices.

Out of curiosity, was there something inherently wrong with the way I was trying to do it or why would only one hole be open?
chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: Issue with Sketching on curved Surface

Post by chrisb »

namezero111111 wrote: Thu Sep 23, 2021 5:50 am Out of curiosity, was there something inherently wrong with the way I was trying to do it or why would only one hole be open?
I suspect a precision issue too, but Chris_G has sure more insight.
Chris_G wrote: pinged by pinger macro
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
namezero111111
Posts: 14
Joined: Thu May 06, 2021 1:22 pm

Re: [SOLVED] Issue with Sketching on curved Surface

Post by namezero111111 »

Thanks again for your help; I will keep in mind next time I can slice it apart should something like that occur. Great idea; I tinkered with subtractive feature but then I had multiple solids from the "holes" of course.
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Chris_G
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Re: [SOLVED] Issue with Sketching on curved Surface

Post by Chris_G »

I think this is a bug of Sketch_on_surface that I already experienced : for creating the face, the wires are sorted after they have been mapped on the target face, while they should probably be sorted while they are flat 2D. And in the current example, the BoundingBox of the holes and of the main plate are not intersecting.
namezero111111
Posts: 14
Joined: Thu May 06, 2021 1:22 pm

Re: [SOLVED] Issue with Sketching on curved Surface

Post by namezero111111 »

It seems like you have a better understanding of the internals of why this might be; not sure what it means to sort the wires.

Alternatively, maybe the bounding boxes could be intersection by rotating them in the direction of the surface center normal to make them intersect maybe?
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