Lofted Surface in Mastercam 2017

[Seahawker]

I'm new to Mastercam 2017 (upgraded from X7), and I'm trying to create a lofted surface with multiple curves using the window option for my chains. The files are cranial scans that get saved as .iges files with curves consisting of lines that from a head (see image). In X7, I'd easily click lofted surface, select the window of all the curves, select a starting point and the surface was created instantly. In Mcam 2017, when I match the surface configuration settings as X7 it takes forever and creates thousands of surfaces that wrap from top to bottom. When I change the setting from NURBS to a curve generated surface, the single surface is created similar to X7. The problem is I need to re-save the file as an .iges and 2017 crashes every time when it's curve generated. When it creates the thousands of surfaces (NURBS setting) I can save as .iges no problem. My goal is to quickly create the SINGLE surface, and re-save just the surface as the new .iges file. Any help would be greatly appreciated!!

[Pete Rimkus from CNC Software Inc.]

1 hour ago, Seahawker said:

The problem is I need to re-save the file as an .iges and 2017 crashes every time when it's curve generated

Any chance you can send us the MC file and we can look into why the SaveAs IGES is crashing?

[Seahawker]

Thanks Pete for the reply. Attached is the MC file with the lofted surface created. I'd love to pick the just the surface and "Save Some" as  an .iges file. Ugh.

Crash.mcam

[Pete Rimkus from CNC Software Inc.]

I don't get a crash in the soon-to-be-released MC 2018, but I can't get that Surface exported to an IGES file either.

The main problem is that our curve-generated 'loft' surface type does not translate nicely to the IGES surface formats. So we try to convert it to a NURB during the export.

But due to to the amount of data points and the curvature of the surface we're hitting a limit I wasn't even aware existed, and the convertor to NURBS is failing.

Let me see what I can come up with as an alternative.

[Seahawker]

Thanks Pete, it's weird because in X7 I have it set as NURBS and it makes 1 surface instantly. In 2017, it creates a ton of tall, skinny surfaces due to all the data points. But the native .iges file opened in both versions start as 4000 lines in the point cloud. 

[Pete Rimkus from CNC Software Inc.]

I've logged the IGES Export issue as R-13088, and the Loft Creation issue as R-13089. Thanks for posting about these issues.

Neither will be able to be fixed before the release of Mastercam 2018, but we will try to address them in the near future.

(And after all that, if this Pats fan finds out that your user name was chosen because of your love of Pete Carroll and the 'Hawks, maybe it'll take even longer to fix! .... j/k)

[Seahawker]

Let me add, what I'm trying to do is have a surface in Solidworks. If I could bring the native file into Solidworks and quickly create the lofted surface, that would be even better. I've just never found a way to do that in Solidworks, quickly. So the file from Mastercam to Solidworks can be anything, it doesn't have to be an .iges. 

(And I'm not some bandwagon 'Hawks fan, I've had season tickets since way back when they suuuuuucked!)

[Pete Rimkus from CNC Software Inc.]

Here's a response from the Product Owner of the CAD functionality in Mastercam: 

".... Since around X7 or X8 we do not create surfaces with sharp corners, instead we break up what used to be a single surface into multiple surfaces. The fact that these are line segments makes me pretty confident there are a lot of discontinuities or sharp corners. ... Before doing the loft the user should run Spline from curves and turn on Sharp Corner Smoothing which will make nice tiny blends between the sharps. The resulting Loft from the splines will be a much higher quality surface than the one from lines is. If the lines were converted to a spline previously and it has sharps then run Refit spline and it fixes it...."

He sent me a version of your file with the original loft profiles smoothed and then the whole thing surfaced. It's attached.

Hope this helps your process.

R-13089 after cleanup.zip

Edited May 31, 2017 by Pete Rimkus from CNC Software Inc.

[Seahawker]

Thanks Pete! Having to convert the lines into splines prior to creating a surface is an added step, but it does work great. Thanks for the help, much appreciated!

[Albertlee]

I am not good at handling this.

[Aaron Eberhard]

I realize this thread's a bit old, but this is a perfect example of when to use the new Edit Spline. After you convert them to a spline (which you can easily do from the top view with window select), it'll easily let you get rid of those spikes (assuming that's just noise from the CMM process):

Start with deleting the really obviously bad points

Then, tweak the two remaining ones to get rid of the bump: