Crash: Getting 'ABORT: Internal polygon error 71' when running ratsnest command

[Anonymous]

Hi all,

Working on a largish board, and when I run ratsnest, I'm getting "ABORT: Internal polygon error 71" with some random coordinates that point to essentially nowhere interesting. Old forum posts point to the width of the dimensional outline, but changing that width doesn't help. Also, this happens in both EAGLE 7.7 and 9.2.2. Any ideas?

I tried attaching my board file, but the forum post form wouldn't work if I attached a file 😞 I uploaded to my Google Drive; you can find it here: https://drive.google.com/file/d/1ODIkK60an_ZSfohssp8MJirCDYy5rzQV/view?usp=sharing

Thanks!

[didrik.madheden · Accepted solution]

Did you edit the uploaded file just now? I downloaded a copy and then a new copy, and the new copy is lacking the bottom layer and no longer has the parallel traces routed.

The issue seems to be with generation of thermals, ie the small tracks that are generated instead of connecting a pad fully to a plane, which helps with solderability. While this seems like a bug that Autodesk needs to look into, here are two suggested workarounds:

1) Click properties for the top ground plane and disable thermals. This is however not ideal because it might affect the soldering properties and for example cause dry joints, when a pad with thermals would not.

2) Create two (or more) ground planes covering smaller parts of the board, for example the top half and bottom half. It seems like the ground planes are allowed to overlap, so you will still get a continuous plane. Each polygon just can't cover more than some magic number of these connectors.

I'm guessing the root of the problem is that the footprint of the connector itself is specifying that holes should have thermals while also covering the top layer with a polygon within the component, causing some sort of conflict within the geometric engine of Eagle. If you could edit the component and remove those polygons, that would probably also solve the issue while also probably not affecting performance since you're filling roughly the same area with copper anyway.

[jorge_garcia]

Hi @Anonymous,

I hope you're doing well. Thanks for posting about this issue. I can reproduce it, I have created a bug report and have attached your file for analysis. We should have this resolved shortly.

Please let me know if there's anything else I can do for you.

Best Regards,

[Anonymous]

Hi @didrik.madheden,

Excellent debugging work! you're correct, if I turn off thermals on the ground plane, the abort goes away. I can move on with the design, but you're right, I'm going to need those thermals. Luckily, it looks like @jorge_garcia has the file and can reproduce the bug, so hopefully that'll be fixed in the next update. Thanks again @didrik.madheden!

Andrew

[didrik.madheden]

As I said though, the other suggestion is to place two smaller overlapping ground planes covering about half of the board. This would let you continue working without crashes, and still have thermals enabled. This should 100% fix your issue without having to wait for the fix to come out.

[Anonymous · Accepted solution]

Yep, that works, too. Thank you! I'm marking this as resolved, although it should be noted when Autodesk actually fixes this bug.