Sand Core design

[cadmonkey2001]

I am designing a transmission case with a cast outer and sand core inner. The cast model will consist of and external merge feature (outer) and a external cutout feature (inner core). How do I offset the surfaces of the outer core to define the wall thickness and the inner core?...The inner core needs to be a separate part so a simple shell won't work in this case. Also, simply making the inner core geometry smaller for wall thickness doesn't work either because the geometry is to complicated, The inner surfaces must be an offset of the exterior surfaces (in two seperate models). Any help would be greatly appreciated.

 

[mloew]

cadmonkey2001,

You may wish to capture the shared, engineering driven, and interface geometry in a skeleton model. The skeleton model can then be used as a template that will drive down the design details into the casting part and the core. This is a pretty standard technique, although there are countless others. Do some Googling for some additional background information.

Best regards,

Matthew Ian Loew
"I don't grow up. In me is the small child of my early days" -- M.C. Escher

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[cehall]

Our geometry seldom shells. I usually have to create full interior and exterior surfaces.

May I suggest in your case you make an assembly that creates the final part. Make the cast outer (solid) in one part and the core inner (surface only) in the other part. Then in assembly remove the core inner from the cast outer geometry. Both parts allow exportable data and the final assembly part can be used for inspection