Solids from surfaces (offset surfaces)

[Mark H]

I'm having a problem creating a single closed solid from a group of surfaces. I've done it before with simple surfaces, but this time I have a mix of offset nurbs surfaces and "regular" nurbs surfaces.

 

For the "regular" surfaces the solid creation works fine, but for the offset surfaces, the solid is created in the original non-offset surface position.

 

What I am trying to determine is if anyone else has run into this, or am I doing something wrong. Unfortunately I cannot share the file I have. Running Mill V9.0 SP1.

 

Thanks,

Mark

[Mark H]

Ok, I know, a picture (cad file) is worth a 1000 words. So I extracted one of the offending offset surfaces so that I could share it with anyone interested. I put a file on Cadcam's FTP site (thanks Cadcam). It is called offsetsurf2solid.zip

 

On level 1 you will find the surfaces and wireframe, on level 2 (not visible) you will find the solids that were created. It should have been one "closed solid body", not two "open sheet bodies".

 

I know I can recreate the surface, but I have more than one, and time is money... Any suggestions?

[cadcam]

I found a big Gap in the top surface almost .080 this why it won't stitch.

 

Sorry I was wrong now that I have had sleep.

 

[ 06-14-2002, 10:35 AM: Message edited by: cadcam ]

[Mark H]

Thanks for taking a look at it, but I dont see the gap in the surface. However, I do see the gap in the solid that was created from the surfaces. As if the solid was using the offset surface's original (blanked) surface, and not the offset surface. (If that make any sense.)

[ProductDevelopmentGuy]

This was indeed a common problem in V9.0 that I thought we had addressed in the SP. I'll take a look at the file.

PDG

[Mark H]

Thanks PDG. FYI I was able to create a new surface over top of the offset surfaces and the solid came out perfect - one closed solid body. Also I submitted it to QC at Mastercam. One final note, simple offset surfaces do work when creating solids, but this surface was trimmed, and was more complex.

[ProductDevelopmentGuy]

Mark,

That's what I found too. I walked through the debugger with these surfaces and Parasolid's offsetting function burped on the trimmed offset, but if I untrim it, the offsetting works. I'm looking to see if there's something in the way we use their offsetting function(s).

I also wrote your surfaces out to IGES and tried to import them into SolidWorks. I got an imported surface entity that could not be stitched into a solid body, and there was a funny looking wrinkle where the trimmed offset surface and the tiny trimmed non-offset next to it met. So it looks like SW hasn't completely solved this either.

We just got Parasolid V14 in-house, so I'll also give it a try with that.

PDG

[cadcam]

Sounds Like you guys went at it the way I was.

I was unblanking the surface and was going retrim it to the Curve.

JM2C

[kwolf]

Try low cost Rhino3d . Maybe that solved the problem.