DMSS Design and Manufacturing Six Sigma Training 

Gear Noise Reduction

A trade partner reported that customers were complaining about a high pitch gear noise on some units.  They tested a few themselves and found under certain loads, the noise was quite high.  They were upset enough to threaten to stop buying the product, which would create a huge financial gap in the plan.  Quick work of multiple DOE's gave insight into the tolerance stack up and what the true tolerances in alignment of key gear components should be.   Adjustments were made and the high pitch wine was reduced significantly, so much so that the trade partners were quite happy and the sales plan remained in tact, all completed in a 3 week time span.

Powder Coat over Zinc Die Cast

The application of paint over zinc die cast can be very challenging.  The quality of the casting and the amount of porosity can greatly affect the paint yield.  Through a series of over 8 experiments that were run on zinc die casting machines, robotic polish for parting line removal and the paint process itself, paint yields for a specific part increased by 20%.  This resulted in over $200,000 of savings.  This also led to the development of a lower curing powder coat technology.

Coffee Grinder Noise

A retro style coffee grinder was created but there were field complaints that some of them were too loud.  DOE methods used to investigate and adjusted critical factors led to a 20 dB decrease in the units that were defective as well as creating a prevention method.

Paint Defects Improvement

When applying powder coat, if the coating is too thin, it can result in the substrate showing through.  On the other hand, too thick of a coating will result in a heavy orange peel look.   This is not acceptable for units with Class A finish requirements.  The 3D shapes of the parts being coated made it quite difficult for the operators and the automation systems to obtain the optimal coating thickness.  Variation studies were done which led to reducing the range of the paint thickness from 1-10 mils, to 2-6 mils.  This resulted in less rework and scrap cost as well as an overall material usage reduction and saved over $150,000.