2D Rhino to Autocad export and rhino sectioning

Hi guys, I prefer to make my 2d drawings in rhino,and then export to autocad to finish them up and print.
The thing is that I always have a hard time exporting from rhino to autocad.
How should I use the settings in the export file window?
(simplify tolerance, max angle, chord height etc.)

Also:
When I make sections of a 3d surface in rhino sometimes they are not accurate...and sometimes even very different from the surface i'm sectioning!
Why? Is this because of surface problems?
Thanks for your help
Federico

I find Rhino very hard to fair a hull surface. Programs like maxsurf and Autoship are much better suited for this. I would say if your contour lines are off then your surface is not right to begin with. My experience is that when I think it is the computers fault it is usually mine. Rhino is very stable and accurate if the information you feed it is correct.

I usually export my contour lines as a DXF file. You can do this by selecting the lines and exporting selected. Make sure the settings are AutoCad ? whatever version you use and that the lines are represented as splines not polylines. Splines will give you a fair curve, while polylines will be a series of straight lines. Then bump up the tolerances at the bottom of the export box. I had problems with consistant shape until I changed the angle tolerance. It takes longer to export and import these shapes at higher tolerances but it is the final shape you are concerned with.

I hope this helps you out. I am still learning Rhino day after day. These things seem to work for me.

Cheers

Thanks!
The strange thing is that I use maxsurf to fair hull lines and it does a wonderfull job, i get good sections etc.
When I import to rhino to complete the design process i get strange sections also where i used to have fair lines in M.surf.
I think the 2 software houses should join forces to develope a full compatibility (I still get problems importing rhino trimmed surfaces to m.surf in version 10) since m.surf and rhino seem to be the number one choice for most of us.

I kinda solved the rhino to autocad export problem using acis sat file format...it seems to do a good job.

Fede,
When you get the inaccurate section lines in Rhino do you ever check the model for bad geometry. This can sometimes cause lines and suraces to show wrong. You may just need to recreate the surface differently.
To check bad geomtery, I would turn all the layers on then go to Analyze in the top toolbar, then Diagnostic -> select bad objects

I hope this helps.

I always transfer the surface using iges format and seem to get good results. Rhino does not do trimmed nurbs. All info about the surface is saved so you can untrim it. I too have had problems going back to Maxsurf because they do allow trimmed nurb surfaces. It would be nice to have a truely seemless transfer but I find Rhino the best out there. I always double check the tolerances of the exported file after finding out the hard way the shapes can change a lot. These are the two best tools out there in my mind at the moment. Now if Rhino could just get the 2d layout stuff together we can finally put autocad to rest.

Cheers

fede said:

Hi guys, I prefer to make my 2d drawings in rhino,and then export to autocad to finish them up and print.
The thing is that I always have a hard time exporting from rhino to autocad.
How should I use the settings in the export file window?
(simplify tolerance, max angle, chord height etc.)

Also:
When I make sections of a 3d surface in rhino sometimes they are not accurate...and sometimes even very different from the surface i'm sectioning!
Why? Is this because of surface problems?
Thanks for your help
Federico

Click to expand...

It might be the precision settings in rhino... To start with the surfaces don't always display properly if you have them set to render quickly... Then there's the issue of the tolerances of points and lines... Change the render settings and precision settings and your results might improve... For situations like this it is most useful if you can attach a file that illustrates your problem....

Cheers,

Dave

DaveB is correct, this will be a problem with settings in Rhino. In my experience the NURBS exported from Maxsurf are fine and Rhino reads and reproduces them perfectly.

What do you thing about the way to import complete 3d Rhino Models into AutoCAD as mentioned already by you and then doing there all drawings in AutoCAD?

The way is the following:

Save the Rhino-file as ACIS (4.0) not higher. Go to AutoCAD , Insert ACIS.

Acis solved all my problems, as far as sections...yes it was a problem of precision settings in Rhino.
Thank you!

archnav.de said:

What do you thing about the way to import complete 3d Rhino Models into AutoCAD as mentioned already by you and then doing there all drawings in AutoCAD?

The way is the following:

Save the Rhino-file as ACIS (4.0) not higher. Go to AutoCAD , Insert ACIS.

Click to expand...

thanks for the solution, but my question is what happen if we just export rhino lines to dxf/dwg file? (with different option between polyline/spline of course, wich one better? )
is it much different?

rgrds,

Need help someone....
How to import my autocad line plan file to maxsurf? I need to make a hull form using maxsurf pro 11 from autocad format. TQ...

need to use marker ... u can find details on it in the manual.. just check the manual

jimianbu you can import dxf lines from autocad into maxsurf as long as they are lines in segments(vector)