Trim Surfaces

[weirdharold]

Have a real simple question for the ones that know. When I import a solid in & need to convert to surfaces , I'll use the screen statistics to make sure it made the surfaces. My question is, it may show (xxx trimmed surfaces and or xxx untrimmed surfaces ) . How do you tell the difference between trimmed surfaces & untrimmed surfaces & why some trimmed & some untrimmed ? Thanks in advance. Harold c

[Mike Mattera]

Most trimmed surfaces have a "base" surface underneath. They are the original boundary. The Un-trimmed surfaces are hidden (Usually).

Think of it as taking a sheet of cloth and then trimming the material you need to make a shirt. The pattern of the shirt is the trimmed boundary made from the un-trimmed sheet.

Mike Mattera

[JIMMY]

Good way to explain it.

[Mike Mattera]

That's what I do for a living. I try to find the best way to explain something, so everyone can understand it.

Mike Mattera

[Steve Arteman]

Not all surfaces are trim surfaces on a model. This makes it hard to tell why you have the number you have. If you create a ruled surface between 2 lines and you just want that surface and build from the edges of that ruled surface it is not a trimmed surface unless you trim something from it like a circle for a hole or a line but is very usable without being a trimmed surface. If you have a surface model that has untrimmed surfaces.Do a analyze test surfaces, check base surface, it will ask if you would like to blank base surfaces if it finds them say yes. the base surface is the original surface before it was trimmed as Mike said. if there is no base surface visable you are probably ok to use the part model.

Check out my surface modeling traing cd at

http://www.cad2cam.net/mastercamx_basic_surface%20.html

Steve
www.cad2cam.net

[cadcam]

Allot of the time you can find the parent surfaces from a surface file, Lets say an Iges file you brought in. if you use the unblank option, If there are parent surfaces (being the untrimed surfaces Mike was talking about) they will show in the screen for you to choose to unblank and keep visible. Example below.

[lovecnc2003]

thanks