Open Loops in NEST Exports

[steven.coxVCM6J]

Hi all,

We have discovered a problem that eats up a lot of time.  When we export a nest to a dxf, there are open loops in some of the parts.  While the gaps are small, the cutting table cannot recognize a loop and fails to cut.

They are obviously closed when the parts are nested or they would not nest (nor would Inventor create a face).

Any ideas how to avoid this or correct it easily before we send it to the table?

Thanks, Steven

Inventor 2023.2.1 build 271

Inventor Nesting 2023 version 7.0.24

[steven.coxVCM6J]

Has anyone else seen this or have any suggestions?

[pcrawley]

This isn't an answer to the problem - but it might help you find the open loops and fix them.

Open the nest DXF in AutoCAD.  Enter "BH" on the command line (short for boundary hatch) and AutoCAD will highlight all the open loops for you. This alone will help you fix the DXF so you aren't sending junk to the table.

Under the bh options, there is a gap-jumping tolerance value.    You can sometimes set this larger that the widest gap and AutoCAD will create a valid boundary.  Honestly though, this fails for me more often than it works (more likely user-error than software error I suspect!)

On the odd occasion I've had the same issue as you, I take the DXF into AutoCAD, create a new layer (make it a bright colour) and make it current.  Then I use the "Boundary" command (not "bh" - "boundary" is different) to create a polyline that represents the closed shape.  When I'm finished creating boundaries for each nested shape, I delete everything from the original imported DXF layer, and I'm left with clean closed polyline boundaries ready for cutting.

[steven.coxVCM6J]

Thanks for the suggestion.  Works great.  Would love better support for NEST though.

Steven

[pcrawley]

"...better support for NEST" - I couldn't agree more!