Chamfer 3 sides (edges) help

[Garry48]

First, I'm relatively new to FreeCad. I have watched lots of videos on youtube, but I have not found how to chamfer less than the entire body. I have a 110mm square and I can not get a 45 degree chamfer on the top three edges. I have used adaptive and added three faces, then tried 3 edges, and I get errors displayed. I'll get bashed for not including the error messages, but I think it is something I am doing incorrectly.
I have attached my file. Can someone walk me through creating a chamfer tool path for the top 3 edges. I want it 6mm deep, with a 3mm step; resulting in 2 passes. TIA

FreeCad Info:
OS: Windows 10 (10.0)
Word size of FreeCAD: 64-bit
Version: 0.20.25645 (Git)
Build type: Release
Branch: master
Hash: 37d9757399b4c2ec30318eb88d7cd7c508246345
Python version: 3.8.10
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.5.2
Locale: English/United States (en_US)

[GeneFC]

This looks a bit like a deburr, but much larger.

I believe the easiest method is to use the Profile operation. Select the sides you want and set the various depths and step-downs.

You may need to adjust the "Extra Offset" at the bottom of the Profile task panel to place the tool centerline on the edges of the model. I believe that a negative offset is required, equal to the tool radius. You might also try a tiny tool size to place the tool on the edge. (FreeCAD does not really know what tools you have in your shop. You can lie if you wish.)

You could probably also make the Deburr operation work or even an engraving operation.

I have never tried this sort of chamfer, but it seems pretty straightforward with the Profile operation.

Someone having experience with chamfering may have a better idea.

Gene

[Garry48]

Thanks Gene,
I finally stumbled on the exactly what you stated. It does work, but the 45 degrees appears as a 30 degree angle on the stock (bit looks like 30 degrees also). The tool is defined as 45 degrees; but actually drawn to 30 degree measurements! Like you said; FreeCad does not know what tools I have in my 'toy box'! So in the end, it should work provided I do not install the wrong bit.
Thanks again
Garry

[GeneFC]

The chamfer tool shape that comes with the usual FreeCAD distribution is set to 60 degrees included angle. You will need to alter the chamfer shape or create a new one. (very easy to do either.)

Also, the v-bit is already set to 90 degrees included angle. You can probably adjust the dimensions to suit.

You can find both of these files in the Shape folder in your tool library.

[Edit: I looked at the chamfer shape in more detail. You should be able to set the angle in the dialog without any editing of the shape itself. The angle is the total included angle, which I believe would be 90 degrees in your case, not 45 degrees. The simulator has recently been upgraded to handle chamfer tools and other shapes, but it appears to me to have some limits on allowable angles. If I follow the code correctly it appears that your chosen 45 degrees would actually result in a chamfer angle of 67.5 degrees. Perhaps an expert can further explain.

The actual chamfer shape is illustrated here.

Capture.PNG (9.23 KiB) Viewed 1115 times

This appears inconsistent with the editing task you showed above. For 60 degrees both views are the same, but for any other angle they are not.]

Gene