Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001

66.2 MOST SIGNIFICANT FEATURE FIRST

 

· Generally we can identify the most significant geometry. Some things to look for are,

  1. - the features are all cut from a base piece - cutting
  2. - there is a natural parting line - welding/molding/casting
  3. - features seem to be stuck-on a base piece. - assembly/molding/casting
  4. - large/small mass
  5. - material

 

· An example of this is an angled block with a hole,

 

 

· Identifying significant features can be difficult, but some experience can help.

 

· Large volumes of metal make parts hard to handle,

 

 

· Thin walls can be difficult to manufacture and will collapse under force,

 

 

· Small hole diameters can be difficult to produce,

 

 

· Tolerances can be difficult to maintain.

 

 

· Surface finish can be difficult to obtain, (micro-inches),

 

 

· Difficult to produce features have preferred processes,

 

 

 

· Materials tend to dictate suitable processes,

 

 

 

· We can use a comparative graph of surface roughness to pick a process.