"My issue is when i import my part from Autodesk inventor using several exporting formals including IGS, STEP, DWG & STL that when the part imports and all looks well when i come to select a boundry almost all round faces are split into several smaller arches.
Okay so thats not a major issue i can just select all untill i have a full circle, but no - It will not accept any boundry."
If the software is not letting you use the boundary, it's because the boundary is "bad"
Bad =
1) It is not a closed shape
2) It's not trimmed properly
3) There are double entities
4) Tangent issues
It's ok, we have tools to fix this... Example, if you chain is made up of tiny little segments, you can optimize the chain into larger segments, or use fit arcs which will help bring the entities count down.
Like you said you had a whole bunch of tinny segments, are you sure you selected them all? Did they chain... these are the things you want to look for.
Al DePoalo
Partner Product Manager BobCAD CAM, Inc. 866-408-3226 X147