The sPINner deburrs small parts using a magnetic disk with circulating polarity to agitate a solution containing stainless steel pins and unfinished workpieces.

Rather than resorting to hand deburring procedures, manufacturers of tiny and intricate workpieces can turn to a new automatic debur-ring device. Reportedly, the sPINner magnetic deburring and polishing system, developed by Techniks Inc., Indianapolis, holds tight tolerances while not damaging smaller, more delicate parts.

The sPINner works by using a magnetic disk below the well of the machine to rotate and excite a solution that contains the parts and a special magnetic media. The media are stainless steel pins that range in size from 0.008 to 0.060 in. in diameter and 0.040 to 0.200 in. in length. The pins are held to tight tolerances and do not vary in size like conventional rock media. The magnets in the magnetic disk are arranged in a circular pattern that changes the polarity constantly as the disk rotates. The constant changing polarity makes the small steel pins jump and spin in the bucket in a circular pattern.

This action polishes the part.

The stainless steel pins are hardened to 30 Rc scale for long use. The size of the media allows it to get into places such as small cross holes and slots where conventional rock media may get lodged or not have access.

The system is fast to load and unload. Steel pins are sifted out of the part batch within 3 to 5 sec using a strainer bucket. Containers are available in 10 and 20-in. diameters.

The system is in use at a manufacturing plant in San Diego that produces small stampings — approximately 0.014-in. 1 1 / 4-in — for a credit-card printer. The company maintains overall flatness from the original form and also deburrs the small 0.030-in. holes in the stamping. The company had employed 10 people to hand deburr the parts, but quality and consistency suffered due to employee turnover and manual limitations. The sPINner yields 200 parts every 3 min with effective and consistent results.