The Significance of Quality Improvement Tools in CNC Machining

Manufacturers talk a lot about quality.  Everyone wants to be known for putting out quality products.  “Quality is our job.” “No one beats our quality!”   Well, “Quality” is a great buzzword, but how can you tell what they mean -if they mean anything?

In the realm of CNC machining, there are a couple of common ways to gauge quality -quality assurance and quality control.  Together they constitute a quality improvement.  The way to determine if a company is actually committed to quality improvement should be easy -just look at what they invest in quality improvement tools and how they use them.

In the Beginning: Quality Control

At Macfab, Quality control starts at the beginning of the manufacturing process.  Measurements are taken when setting up raw stock or castings, even before machining begins.  Then throughout CNC machining, quality control steps are included.

The operators (or often the CNC mills themselves) will pause to take measurements of the part in progress, confirming that specific features meet specifications before proceeding.  This can be vital in some situations. Tensions in the material may cause a part to warp as it’s milled and structures become thinner.  These tensions may be caused during the production of the raw stock or casting, or from heat from the CNC milling process itself.  Features may have been in spec earlier but may shift as the part is shaped further.  Monitoring the details of a part’s shape at various stages of machining allows us to spot where warping is being introduced.  With that knowledge, we can determine how best to handle the situation.

All of those measurements are recorded, most of them automatically, in another quality tool -our ERM software.  Not only does this provide our customers with QC data on their products, but we can use it internally.  If we see similar failures happen on different projects using the same raw stock, that can inform us that our supplier may have a problem with that particular commodity.  Or we may discover that we need to use a different milling bit or different cooling in some circumstances.  Watching for and analyzing failures is vital to genuine quality control.

In the End: Quality Assurance

Once the shaping is finished on a part, quality assurance takes over.  The part is placed into one of our component measuring machines, and every aspect of it is checked again.  The features are compared against the design drawings and the specified tolerances.  Screw holes, curves, surface finishes, recesses, flanges -Macfab’s CMM machines measure it all as part of their quality tools.  Every single measurement winds up in our ERM software and is provided to the customer in an easy-to-read format.

There is one last component to Macfab’s Quality Improvement: our people.  Everyone here is crucial for the continued success of our quality improvement efforts.    Nothing can replace the senses of the operators, who can often spot issues before any measurement system would.  The engineers who design and maintain our ERM software work out how to use the data to monitor systemic problems.

Most of our customers are answerable to their customers for quality assurance.  Macfab provides ample documentation to satisfy the most exacting requirements.  In the end, that’s how you can gauge a company’s commitment to quality improvement.  It’s not one thing, but a culture of attention to detail that permeates an operation as you’ll find at Macfab.


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