“Brush Holder” Engineering Modification for Customer Yield and Field Failure Elimination

The Initial Design

Hewitt Molding Company manufactured this featured one-piece brush holder assembly for a major, industrial pump manufacturer in the Midwest.
Our customer contacted Hewitt Molding in September of 2009 because their component was suffering from internal and external failures, believed to be from the brush holders in manufacturing. The initial design consisted of two, separate brush holders, assembled in-house, which caused production alignment problems. The alignment problems resulted in in-house rejects, late deliveries, and customer returns. Our customer requested our assistance to help redesign these two brush holders as a single-part assembly.

The Revised Engineering Change and Final Design

Hewitt received a motor casting and mapped all the critical mounting holes and other pertinent features. Then, Hewitt created a CAD model and SLA one-piece brush holder, to be submitted for customer engineering approval or adjustments, in just four days.

Our Engineering Design Team worked with our customer to detail areas which they believed needed to be changed from the SLA. Hewitt then made a urethane mold and 15 proto parts, for actual testing and certification, in one week. After testing and UL approval, Hewitt was awarded a contract to build a two-cavity production mold.

Product in Production

This new, one-piece brush holder part saved our customer assembly time, solved alignment and internal quality problems, and ended customer returns. Hewitt also added two springs to each brush holder as a value add to this product. Hewitt has since been supplying six-hundred additional brush holders per day.





Styled Table


Material Type Nylon 30% Glass Filled Material
Cutting Method Insert Over Molded Assembly
Packaging Customer Supplied
Special Feature UL Approved
Industry for Use Industrial Pump Manufacturer
Volume 150,000 Pieces Annually
In Process Testing Performed CMM Inspected and SPC Production Process Control
Design Work Completed in house
Drawing Type Accepted NX, STEP, XT, IGIS, PRT