[Solved] How to create a radially symmetric multitransform that "fans out" (Use Draft WB -> Circular Array)

[physmage]

Code: Select all

OS: macOS 10.16
Word size of FreeCAD: 64-bit
Version: 0.20.1.29410 (Git)
Build type: Release
Branch: (HEAD detached at 0.20.1)
Hash: f5d13554ecc7a456fb6e970568ae5c74ba727563
Python 3.10.5, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.2
Locale: C/Default (C)

Hi, I'm wondering if there is a way to create a multitransform that fans out, increasing in frequency for each radial step. I.e. if the first polar transformation creates 6 copies of the feature, the second will create 12, the third 18, and so on.

The way I started was by applying a linear transformation to a pocket in the body I'm manipulating, then applying a polar transformation, but I'm left with wedges I would like to pocket in the way I described above without having to sketch an entire wedge of the holes to be pocketed then applying a polar transformation.

Any ideas?

[chrisb]

What you are looking for is not available in PartDesign, but can be done with Draft->CircularArray. You have to create a separate body (or Part object) for the cutout, then create the array and subtract the whole array in Part workbench from the body (not from a feature inside).

[drmacro]

Seems like a good application for Lattice 2 workbench.

[papyblaise]

that doesn't exactly answer the question
is there a solution so that the copies are all oriented towards the center

[papyblaise]

is there a solution so that the copies are all oriented towards the center

I found: by orienting the hole perpendicular to the spiral

[chrisb]

Here is the circular array version. Drawback: I cannot remove the single innermost instance:

SnipScreenshot-9635eb.png (47.1 KiB) Viewed 577 times

Papyblaise: You should not apply Part booleans to PartDesign features.

[Jolbas]

@chrisb Did you attach the correct document?

[chrisb]

@chrisb Did you attach the correct document?

It was the wrong one. I replaced it in the post above.

[papyblaise]

You should not apply Part booleans to PartDesign features.

I didn't do that
I didn't know about this circular array function

I also discover that the orientation of the copies towards the Z center depends on the orientation of the original with respect to the X axis
Let me explain: if the original is on the Y axis as it is in the original file, therefore perpendicular to X, it will rotate while remaining vectorially oriented to X

[physmage]

Thanks all for the replies.

@chrisb I like the version you made. Which parameter(s) did you apply to get the array sketches with the correct orientation? I've been comparing to an array I made and can't spot the difference. My array has each copy of the sketch rotated 90º like the example in the docs.

I think that I should be able to just make a copy of the first iteration and apply a polar transformation to solve the drawback you pointed out.

The one thing I noticed were that the vertices look particularly pronounced..that's not actually 3 dimensional though is it? It's not something that will show up when I go to 3D print this for example, right?