Difficulties with Precision Aerospace Machining

Machine Shops that work on a variety of different types of parts will know that custom machined parts for one industry may have drastically different issues than those machined parts for another industry.  Aerospace components tend to have similarities in what makes them difficult.  A few of the issues that face  include: extremely tight tolerances, large numbers of machined features, large amount of material removed during machining, and multiple quality specifications.

Let’s look at the tight tolerances.  Airplanes are assembled from a huge numbers individually manufactured parts.  Each of these parts needs to be manufactured to a precise tolerance in order to facilitate assembly.  By themselves tight tolerances are merely a norm in the precision machine shop world.  it is when combined with the other factors that the tight tolerances cause difficulties.

The second difficulty of custom aerospace parts is the large number of machined features.  An individual aerospace component may potentially have several hundred individual features.  When you will have hundreds of dimensional checkpoints, even a single feature that is at the edge of tolerance can cascade and cause future dimensions to be further off.  The only way to ensure that a part is going to be good is to hold the earliest tolerances even tighter than what the prints call for.

Implied in the second point is the amount of material removed.  Removing a large amount of material causes it’s own difficulties and stresses on the machinery.  Additionally the material itself will change dramatically as it loses the tensile strength of it’s original form while being  machined.  The programming and fixturing of the custom machined part needs to account for the changing strength of the material while simultaneously ensuring that tolerances are kept throughout.

Finally, in addition to the other issues, aerospace parts tend to have many external quality standards in terms of fit and finish.  The cosmetics need to be pristine and the painting or plating needs to be done exceptionally well.

The 2 parts pictured below exemplify some of the complexities of custom machined aerospace parts.

Here are some additional custom machined parts that we have made.

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CNC Industries is a Fort Wayne, Indiana based machine shop specializing in precision CNC machining, fabrication and assembly of application-critical and custom machined parts for the Aerospace, Defense, Medical, Industrial and Transportation  markets.   The company presently employs approximately 55 people.

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