[Solved] Holes, holes, holes...

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BigChipmunk
Posts: 2
Joined: Tue Jan 31, 2023 12:58 am

[Solved] Holes, holes, holes...

Post by BigChipmunk »

Hi Team, I am a newbie to FreeCAD and this forum. I have read the rules so if I am doing something wrong please let me know.

I followed this tutorial: https://wiki.freecadweb.org/Creating_a_ ... th_Part_WB. After I cut the hole in the part, the hole still appears to be "full". It's like it made the cut, but didn't remove the inside of the hole. Pictures of the tutorial image and my image are in the attached document. I also attached the freecad file.

I just updated freecad and I'm on

Code: Select all

OS: Linux Mint 20.3 (X-Cinnamon/cinnamon)
Word size of FreeCAD: 64-bit
Version: 0.20.2.29603 (Git) AppImage
Build type: Release
Branch: (HEAD detached at 0.20.2)
Hash: 930dd9a76203a3260b1e6256c70c1c3cad8c5cb8
Python 3.10.8, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: English/United States (en_US)
Now on to what I am really trying to accomplish. I have an SVG of a part. I need to extrude the part (at an angle) such that it has angled holes through it. The part is a ventilation louver for a boat.

On my first attempt, I thought I had it pretty good, but when I went to cut the part on a router, I realized that the main body of the part had no front or back to it - it was just the edge that was extruded.

On the next attempt, I made sure that the main body was a solid with a front, back, and edge, and I seem to have that now. What I cannot figure out is how to make the holes "empty". In fact, I don't even know how to tell whether or not they are empty. If I look at the wireframe I can see all the correct internal structure, but I don't know if there is anything in the holes, or not.

The holes need to be cut very accurately so I would like to avoid having to recreate the holes from scratch. I would like to use the geometry of holes that is already there in the SVG that I started with. The holes are the 6 long slots.

Is this possible?

Lawrence
Attachments
stern louver 8.FCStd
The part I'm trying to make
(675.87 KiB) Downloaded 18 times
tutorial 1.FCStd
Tutorial
(14.01 KiB) Downloaded 16 times
Holes.odt
Results of tutorial
(20.56 KiB) Downloaded 22 times
Last edited by BigChipmunk on Thu Feb 02, 2023 3:39 pm, edited 1 time in total.
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papyblaise
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Posts: 7864
Joined: Thu Jun 13, 2019 4:28 pm
Location: France

Re: Holes, holes, holes...

Post by papyblaise »

you have made a lot of duplicates, you should only have one copy of each
fusion all holes together, then subtracts this merge from the base
in the end you must have only one part
Attachments
stern louver.FCStd
(306.14 KiB) Downloaded 12 times
domad
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Posts: 2051
Joined: Mon Jun 22, 2020 12:16 pm

Re: Holes, holes, holes...

Post by domad »

BigChipmunk wrote: Tue Jan 31, 2023 2:26 am .....
Hi BigChipmunk, Greetings to the Community!
Assuming that the external profile has imperfections (a "serrated" on the short sides), modeling can be done in many different ways, all more or less valid, also using workflows that employ different workbenches such as "Part Design " or "Part+Draft", the latter is what you have chosen, but not exactly a correct workflow.
You have created many single extrusions (one for each crack) which overlap each other and cover each other.
Wanting to use your flow you have to create an extrusion for the shape of the object, then create an extrusion for each slot then create a "composite" of these extrusions (slots) and finally make a boolean cut between the shape of the object and the composed.
Attached is an alternative flow (which is not the best) in which the compound was used as a union of the faces of the cracks and then the boolean cut was made between the face of the object and the compound (faces of the cracks).
You will understand how I did it by analyzing the individual steps where, moreover, they are indicated in the "Description" column of the "Tree view".
Attachments
stern louver 8_domad.FCStd
(248.84 KiB) Downloaded 14 times
stern louver 8_domad.png
stern louver 8_domad.png (88.65 KiB) Viewed 469 times
BigChipmunk
Posts: 2
Joined: Tue Jan 31, 2023 12:58 am

Re: Holes, holes, holes...

Post by BigChipmunk »

papyblaise wrote: Tue Jan 31, 2023 8:39 am
Thank you so much papyblaise and domad! Your solution worked perfectly. And so fast also. I took some time to reply because I wanted to make sure I did not have any more questions for you.

You also taught me some important things about shapes and booleans and how to use them.

Thank you again!
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