High-Energy Mass Finishing

Q. We produce two parts that cannot be deburred in our bowl vibratory machine. One is a small (0.35 × 0.25 × 0.20-inch) machined 304 stainless part with large burrs, and the other is a 0.375-inch diameter × 0.02-inch stamped stainless flat washer. We have tried all types of media and time cycles. Is there another finishing system that would deburr these parts? —B.K.

A. Small parts with large burrs and flat parts that stick together can be difficult to deburr or process in vibratory machines. There are a number of high-energy mass finishing systems that are 10 to 20 times the energy of vibratory machines.

The centrifugal barrel (CB) is a good choice for your application because it’s capable of driving smaller media with significant energy to deburr large burrs in tight areas of smaller, lighter parts. As a batch processing machine, it enables glass beads to be added to the media to eliminate the surface tension that keeps small, light, flat, wet parts from sticking together.

The CB machine looks and operates similar to a ferris wheel on steroids. The energy is produced by a variable speed (1 to 240 rpm) rotating turret, with two to four hexagon-shaped barrels mounted within the turret, counter rotating at a 1-to-1 ratio. The media and parts are contained within the fully enclosed barrels producing a compressive-sliding-grinding action. 

The centrifugal barrel produces amongst the highest energy of all the mass-finishing systems, with up to 20 times the energy of vibratory systems. Other advantages of using a CB include the ability to divide barrels to separate large parts, short time cycles and the ability to process wet or dry. 
Disadvantages include the fact that part loading/unloading is a bit cumbersome, taking 10-15 min of operator attendance, but it will successfully run a lot of hard-to-process parts. The CB also is only capable of batch processing, and it cannot be automated.