How to mill a simple cut out?

[Wsk8]

Hello,
can anybody tell me, how to mill a simple cut out like this?
And no, i don't want to mill around the entire piece! Only the circled path.

[PedjaS]

From what I read, ToolPath cannot be set on unclosed surface like one you have.

If you already have peace of material that is right dimensions and you only need to cut out that notch, I guess the simplest way to do is to add imaginary fourth surface.

For example add cube at the outer edge of the shape and fuse it so it all becames one piece with pocket. Then you would be able to create Pocket Path making toll think it is cutting material but actually just floating through empty space. Extend pocket a bit into imaginary surface to compensate for drill width to get sharp edge.

[dubstar-04]

Hello,
can anybody tell me, how to mill a simple cut out like this?
And no, i don't want to mill around the entire piece! Only the circled path.

Can you post the file and your FreeCAD version?

Thanks,

Dan

[chrisb]

Use a Boundary Dressup (0.19).

[Wsk8]

Adaptive Clearing would create a good path, but if i apply the boundary dressup, i get an error:

Traceback (most recent call last):
File "C:\Users\p\Downloads\FreeCAD_0.19.19373_x64_Conda_Py3QT5-WinVS2015\Mod\Path\PathScripts\PathDressupPathBoundary.py", line 114, in execute
inside = edge.common(boundary).Edges
<class 'AttributeError'>: 'NoneType' object has no attribute 'common'
302.645 <App> Document.cpp(3462): Failed to recompute Unnamed#DressupPathBoundary: 'NoneType' object has no attribute 'common'
Recompute failed! Please check report view.

And with other ops, i couldn't even create a path.

Also i don't want to modify my existing model.

Code: Select all

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.19373 (Git)
Build type: Release
Branch: master
Hash: c47512b7b2b3b64b4a21a86ad34a565459a13e6a
Python version: 3.7.3
Qt version: 5.12.5
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: German/Germany (de_DE)

[chrisb]

Please retry with the most recent version, although I'm not sure if Adaptive+Boundary works. Profile and Contour should work.
Upload your file with what you got so far.

[CoderMusashi]

Check out this forum post and the youtube videos.. https://forum.freecadweb.org/viewtopic.php?f=36&t=41781. There are several ways to go about this and they are all straight forward and use the same concepts.

[chrisb]

There are several ways to go about this and they are all straight forward and use the same concepts.

Your solution is interesting, but it requires quite some steps and additional coding, as far as I can see. It may improve usability if you could create an end user friendly Path operation where the necessary parameters are collected in a panel as with the other operations and then all the rest is created automatically.

[CoderMusashi]

The approach so far has not taken into account the square corners. This is a simple straight forward task here I used the same technique (minus the feature area) to do a simple single line tool path. I drew a constrained single line sketch in the middle of the 1/2" slot since we can use a 1/2" end mill to cut the slot. I made the line long enough to compensate for the tool diameter so it would have lead in and lead out. Took less than a minute to accomplish the tool path for this and it took more time to create the model and sketch. I edited the Gcode right in Freecad using the inspect gcode tool so I skipped a few steps that are in my forum post. I only used the code from the first and last macros from that forum post.

[CoderMusashi]

For an easy to use way of making tool path you can create wires from edges in the part workbench or create sketches of the tool path that compensate for your tool diameter. Then use the engrave tool to create a path from those selected edges. The engrave tool path does a great job at following an edge and stepping down. In the picture below I created a wire to compensate for a 1/4" end mill.