CNC Path for Raised Lettering

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doxley
Posts: 35
Joined: Tue Jun 18, 2019 6:55 pm

CNC Path for Raised Lettering

Post by doxley »

I'm trying to use FreeCAD to create the CNC code to create raised lettering from a block of stock (I've successfully done engraving using ShapeString). I'm clearly missing something fundamental. Near as I can tell, I need to use a sketch built from the base ShapesString in order to construct a perimeter which in turn **should** allow me to identify as a face the stock outside of the lettering. I've tried a number of approaches and all have failed.

In the attached project, I have a sketch (Sketch001) from the letter ShapeString. I have a sketch (Sketch) used to make a Pad for the stock and a third sketch (Sketch002) which is the merge of the other sketches with the intent of using it to guide the Paths. (In an earlier attempt, I just used the ShapeString which I extruded to create the desired 3D body, but could not get Path to work outside of the lettering)

I've been unable to find an example to follow which would be great or any advice on where I went wrong or how to proceed would be appreciated. I did validate the sketch.

I'm running:
OS: Ubuntu 20.04.2 LTS (ubuntu:GNOME/ubuntu)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Branch: unknown
Hash: 9e3b630bbfb6807e93eeffb655e6c20f218644fc
Python version: 3.8.5
Qt version: 5.12.8
Coin version: 4.0.0
OCC version: 7.5.1
Locale: English/United States (en_US)

The project can be retrieved from: https://drive.google.com/file/d/1cqKsgM ... sp=sharing

Thanks,
--Don
chrisb
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Posts: 53951
Joined: Tue Mar 17, 2015 9:14 am

Re: CNC Path for Raised Lettering

Post by chrisb »

If you want to mill around the string you can use a profile operation:
Attachments
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A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
doxley
Posts: 35
Joined: Tue Jun 18, 2019 6:55 pm

Re: CNC Path for Raised Lettering

Post by doxley »

Thanks for the reply. I thought I tried that. Am I correct that:
(1) Create Part - Body - stock (reversed on XY plane)
(2) Create ShapeString in Part (not Body) - position slightly above XY plane
(3) Create Job - Run Profile.

Am I missing something?

Thx,
--Don
chrisb
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Posts: 53951
Joined: Tue Mar 17, 2015 9:14 am

Re: CNC Path for Raised Lettering

Post by chrisb »

doxley wrote: Tue Jun 22, 2021 1:08 pm Am I missing something?
I just took your model and created the profile - without selecting anything. That means you can create the ShapeString in Draft workbench in XY plane and create the job directly.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
doxley
Posts: 35
Joined: Tue Jun 18, 2019 6:55 pm

Re: CNC Path for Raised Lettering

Post by doxley »

(sorry, was pulled away so just got a chance to try it). You are right. I'm a little confused that I don't need to specify the base geometry in order to select which 'faces' to mill, but it certainly works.

Thanks,
--Don
chrisb
Veteran
Posts: 53951
Joined: Tue Mar 17, 2015 9:14 am

Re: CNC Path for Raised Lettering

Post by chrisb »

doxley wrote: Thu Jun 24, 2021 12:09 am I'm a little confused that I don't need to specify the base geometry in order to select which 'faces' to mill, but it certainly works.
There used to be a separate operation "Contour", which did what now is done by Profile without any separate base geometry: create a mill path around the whole object. This concept fits well into the FreeCAD philosophy, you find it e.g. with ShapeBinders or paths for PartDesign sweeps.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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