Spiral pocket cut with extensions

[howard]

Following on from my last post I think there is a bug in the spiral cut with extensions.

When I do a cut sections of the pocket are not cut. The larger the extension the bigger the problem. Also when decreasing the overlap the path moves away from center towards the edges, EG - 100%

Screenshot 2022-01-25 104801.png (12.24 KiB) Viewed 1259 times

then 10%

Screenshot 2022-01-25 104842.png (7.13 KiB) Viewed 1259 times

I tried to look at the python code, but afraid it is well beyond my coding expertise. Hopefully a simple fix, I guess that the number of paths is being calculated without the extensions, then the path positions are calculated with extensions?

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.20.26858 (Git)
Build type: Release
Branch: master
Hash: e209bc706d35121098f9bac779bc6b09c24ddd95
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.3
Locale: English/United States (en_US)

[chrisb]

I can confirm the issue.

ZigZagOffset looks in this case pretty good.

[GeneFC]

I have never had much luck with "Spiral". I typically use "Offset", which works in this case.

I hate "Zig-zag", although it often works. My issue is that even if it is working perfectly it leaves artifacts on the finished material.

Gene

[sliptonic]

Can we just disable spiral? Is there ever a case where spiral is preferrable to adaptive? The spiral pattern is implemented in C++ so not easily modified (at least by me) and has been a source of confusion for a long time.

To be honest, I'm not sure how valuable line, triangle, and grid are either.

[GeneFC]

To be honest, I'm not sure how valuable line, triangle, and grid are either.

As you know, I have been pretty active on the forum for the past 6 years or so. I have downloaded thousands of FCStd files to look at. I do not recall ever seeing any file that used triangle or grid patterns. I am sure I have personally never used either of those.

Line is used in other operations, of course, but I am not sure how it would be used in Pocket.

Gene

[howard]

Many thanks - words of wisdom from the CAD gods. I would suggest you just turn them off in the GUI, they got me all confused.

Offset is doing the job perfectly.