How to create a g-code PATH for a large circular chamfer ?

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beding
Posts: 6
Joined: Sun Oct 04, 2020 4:30 pm

How to create a g-code PATH for a large circular chamfer ?

Postby beding » Tue Apr 13, 2021 7:43 pm

Suppose I have a part with a large circular hole, 100mm and the edges have a chamfer 45 degree 10mm.
Which operation is to be used to create g-code?
Do I need a 90 degree bit?
Can it be done using a bal-end bit?
RatonLaveur
Posts: 976
Joined: Wed Mar 27, 2019 10:45 am

Re: How to create a g-code PATH for a large circular chamfer ?

Postby RatonLaveur » Tue Apr 13, 2021 8:42 pm

Hi, well you can do both.

There is a Chamfer OP in path that will generate a path based on an edge and for which the toolpath is offset according to calculations for a chamfer tool bit (a simple D bit can do the trick if you're a hobbyist with the tools to make it).

Alternatively you can use one of the 3D Surface OPs, (dropcutter or water line). To activate then you need to:

1. Enable Experimental Features (the procedure to do so is explaine in the FreeCAD wiki page of the same name.
2. Go to Edit, Preferences, Path, and in the third tab activate OCL based features.

Once you've done that and restarted FreeCAD, the 3D surface OPs will be available as a drop-down menu of 3D Pocket. (i would not rely on 3D pocket for the task, but maybe someone will have a better offer).
chrisb
Posts: 34448
Joined: Tue Mar 17, 2015 9:14 am

Re: How to create a g-code PATH for a large circular chamfer ?

Postby chrisb » Tue Apr 13, 2021 10:39 pm

You should use a 90° mill with the deburr op. You won't get a good chamfer with a ball end mill.
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beding
Posts: 6
Joined: Sun Oct 04, 2020 4:30 pm

Re: How to create a g-code PATH for a large circular chamfer ?

Postby beding » Wed Apr 14, 2021 11:40 am

Hi, Thank you both.
But I cannot find a Deburr or Chamfer OP.
I have the latest FreeCAD 0.19 version (On Windows 10) and enabled OCL Features.
RatonLaveur
Posts: 976
Joined: Wed Mar 27, 2019 10:45 am

Re: How to create a g-code PATH for a large circular chamfer ?

Postby RatonLaveur » Wed Apr 14, 2021 4:59 pm

My super bad, it's the deburr OP. Not chamfer, it does not exist.

https://forum.freecadweb.org/viewtopic.php?f=3&t=40944

Deburr is hidden in the drop-down menu of Engrave in the workbench tools.

Alternatively: in the menus at the top of the screen, go to Path --> Deburr.