DXF Export Error- Exploded and Mirrored Curves

I’ve run into a very strange error and I’m hoping someone can point me in the right direction.

I operate a static cutting table which means that I receive 2D geometry in Rhino which I then run through a nesting software and then import to the table’s cutting software. Our nesting and cutting software both are able to export/read dxf file types so that is what we use.

This system has worked for years- but recently we updated Rhino and I’m getting a replicable error.

If I export a dxf file from our nesting software and import it straight to our cutting software, then it works.

If I create a dxf file in rhino and import it to our cutting software (Without running it through the nesting software) it works.

But if I run a dxf file through our nesting software then open it up in Rhino to make any adjustments (Adding, deleting or moving curves. Nothing to do with any layers or settings.) and resave it as a dxf I will then be able to open it in our cutting software but with the strangest error.
The file will open, but most of the curved lines will have been broken into several small segments and some of those segments will then be flipped so that they are mirrored and outside the original footprint of the geometry.
It’s hard to describe, but these are some screenshots; first of the file as it appears in Rhino and then as it appears in our cutting software.
image
image

And this is the export settings for our nesting software.

I’m at a loss to think of what could explain this and so far haven’t been able to find a solution. I would think that it shouldn’t make a difference- I’m saving the adjusted rhino file as a dxf as I always have.
Up until a few months back I have done this exact thing several times without issue. And those files that I created using this method from before the Rhino update will still open in our cutting software.
The only changed variable seems to be rhino.

Any ideas on what could be causing this or adjustments I could be making to prevent this? Thank you!

Hello - I don’t know about the export dialog you show, but in Rhino, you can get a page with these settngs:

If the displaced curves are arcs, then I would experiment with the marked setting. If arc normal are down and the importing software expects them to be up, then they may be mapped to a different plane.

-Pascal

Thank you so much Pascal!

I’ve run some tests and that seems to have done the trick, at least for the most part.

For some reason, even though I’ve selected to save/“save changes to default”, the “Flip arc normals to +Z” option has been unselected every time I open a new file. Am I missing something to make that a permanent change to the default?

Also, while my curves are now all in the right place they are still blown up so that my text objects from Rhino are interpreted by my cutting software as a million little lines.
I tried just joining the curves in rhino but you can see that, while they can now be selected as one curve, they’re still distinct.

Is there a better means of joining curves into one continuous curve? (Rather, one that can be done en masse like the join feature? I won’t have time to individually join all the many lines to make up each text object of the dozens in each file.)

Thank you again for the suggestion!

Hi Samantha - Can you post a file with an example with the text that blows up?

-Pascal

Of course, this was the file I was running tests with.
Exploded Text Object Error.dxf (417.3 KB)

Hi Samantha - so this is an ‘incoming’ file that you then re-export, is that correct? You do not start with ‘actual’ text in Rhino that needs to be exported? (if you start with a Rhino file, please post that) The text curves are composed of arcs and straights - possibly what is known as polylines with bulge arcs - you can join the curves, SimplifyCrv the result and then when you export, specify how the curves will be handled -

Does any of that help?

-Pascal

My apologies, this is the “Incoming” File.
Original File.dxf (896.8 KB)

Looking more closely at the original file, I can see now that the text is already fragmented, unrelated to my original issue. So this is a whole new problem, my apologies. : J

But I did try your suggestions. If I just join the curves and SimplifyCrv then I run into the same issue cutting my file- the cutting software still recognizes them as individual lines, not a continuous curve. (Plus, I’m still unable to permanently alter the default to select “Flip arc normals to +Z” no matter how many times I “save” in AcadSchemes. I have to manually select it for every file I open.)

If I attempt to export it with the “2007 Natural” scheme and with “Polylines w/bulge arcs” then my cutting software cannot run it at all.

Hi Smantha - there is an Explode polycurves setting on the Curves page which you should leave unchecked ; also, Save or SaveAs the modified scheme to use it again…

Any luck?
-Pascal

Hi Pascal,

I’ve tried Save/SaveAs and the changes have still been erased every time I open a new file.

Also, the “Explode polycurves” is greyed out and I’m unable to uncheck it.

Hm - if you start with Default and SaveAs to a new name, all that stuff should become available - you just do not get to change Default itself.

-Pascal

Thank you! That worked, I was able to name a new scheme and save my changes there.

So, even if I can’t just join the text, I can at least be sure that all my geometry is correct, which is a huge relief. Thanks again.

@samantha.wallace - why not? You should be able to Join and then on export make sure not to explode, with that setting unchecked and it should all work…?
-Pascal

Oh! I might have been using the wrong save file for my last test. I just ran through the whole process from the beginning, with the new scheme. And this time joining the text appears to be working.

I think that’s finally everything. Thank you so much for all the advice!