djm@ecl.psu.edu (05/24/91)
I have used several NC packages: from Computervision, CADAM, CATIA ("big"
CAD systems) and from MasterCAM and SmartCAM ("small" pc based systems).
All require the NC programmer to specify the feature to be cut, specify the
tool, and set cutting parameters (speed, feed, depth of cut for multiple
passes). Some of the problems associated with automatically doing this are
workpiece orientation (how should it be fixtured), size of raw stock,
preferred order of manufacturing operations, as well as recognizing
manufacturing features from the CAD database. There has been some work on
automated NC machining - primarily an approach which defines raw stock,
subtracts the finished part, and decomposes the remaining volume into
subvolumes that can be removed by machining. This is still at the research
stage.
A number of people are working on automated "generative" process planning,
which will be needed to provide the non-geometric machining information
required for automatic manufacture. At least one group (RAMP program in
South Carolina) is working on generative process planning from a PDES database.
Hope this helps.
--
Deb Medeiros
IE Dept.
Penn State University
djm@psuecl.bitnet or djm@ecl.psu.edubruceb@fai.UUCP (Bruce Bailey) (05/28/91)
In article <1991May24.115748.1246@ecl.psu.edu> djm@ecl.psu.edu writes: >I have used several NC packages: from Computervision, CADAM, CATIA ("big" >CAD systems) and from MasterCAM and SmartCAM ("small" pc based systems). >All require the NC programmer to specify the feature to be cut... > >...A number of people are working on automated "generative" process planning, I used to work at Automation Technology Products where we had a "fully" functional Generative NC product, which was integrated with a solid modeller, utilized form feature information, etc... The company went chapter 11 and a spin-off company was formed called Cimplex, Inc. This technology has progressed beyond "research" in that the Cimplex product is currently being used in production at Boeing. Last I heard, the types of parts they are designing and machining are fairly simple (angle brackets with holes). Apparently, this is not due to any limitation in the modeller or GNC package, but due to numerical problems within the NC processor. Bruce Bailey (Dr. OW)