Removing unwanted areas of a cut

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HarryBadger
Posts: 2
Joined: Wed Oct 20, 2021 10:29 pm

Removing unwanted areas of a cut

Post by HarryBadger »

Hi. Relatively noob question and first forum post... I have bought an STL model of a UAV surveillance drone which I am 3D printing. The intention is not for it to actually fly, but rather to be used as a theatrical prop. It comes pre-sliced up into smaller printer-friendly sized pieces. But there are no overlaps or supports for any of the many joins. So I am creating FreeCAD parts to internally brace and support the fuselage, wings etc.

The model is rather curvy and an irregular shape. I thought I could import the STL > Create Shape from Mesh > Convert to solid and then create simple primitives like boxes / cylinders and cut them, leaving perfectly shaped interior parts.

However, due to the irregular shapes, I am left with a cut of multiple elements and I don’t know how to just keep the interior piece that I want.

For example, here is the nose cone.
Screenshot 2021-10-20 222812.png
Screenshot 2021-10-20 222812.png (167.66 KiB) Viewed 442 times
I have created a cube in the position I want to start to building the internal support. After I cut the two parts, I am left with this.
Screenshot 2021-10-20 231812.png
Screenshot 2021-10-20 231812.png (103.66 KiB) Viewed 442 times
I only want to keep the interior piece from the cut. How do I remove the unwanted external piece? Or should I be using another method to create the part e.g. some kind of Boolean?

The nose cone is just one example, but there are 10+ fuselage and wing parts to join together. What the best way of creating these exact fitting interior supporting parts for this model?

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chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: Removing unwanted areas of a cut

Post by chrisb »

Use boolean fragments from Part workbench.
SnipScreenshot-f642d8.png
SnipScreenshot-f642d8.png (39.58 KiB) Viewed 351 times
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HarryBadger
Posts: 2
Joined: Wed Oct 20, 2021 10:29 pm

SOLVED Removing unwanted areas of a cut

Post by HarryBadger »

Thanks for this. I have played with Booleans previously and the split / Boolean fragments, but they were giving me similar results as the cut.

However, reading more on the documentation and chrisb thank you for the example fragments.FCStd - this step I was missing was Part > Compound > Compound Filter
Screenshot 2021-10-21 093414.png
Screenshot 2021-10-21 093414.png (109.99 KiB) Viewed 308 times
I now have the result I was after - Thanks
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