28 at the top of the shaker deck 26 is u215d inch u2212 10 the remaining shaker trays 28 have u00be inch u2212 10 sized perforations in the top surfaces thereof as a result the larger debris is scavenged from the seeds and the clean seeds fall through the perforations of the trays 28 onto the slide 34 the shaker deck 26 is supported by angle irons 60 and leaf springs 62 the shaker trays 28 are agitated by an arm 64 which is oscillated by an eccentric 66 secured to a drive shaft 68 driven by a motor 70 the arm 64 threads into the eccentric 66 and is secured in place by a nut the preferred embodiment comprises a shaker deck 26 which vibrates at a frequency of 500 550 rpm the larger debris falls through the chute 32 to the debris collection bins 42 below any small or loose debris that does not fall into the collection bins 42 is carried away by a suction airwash into a duct 72 the airflow through the duct 72 is regulated by a damper 74 controlled by a handle 76 located above the debris collection bins 42 the preferred embodiment comprises a duct 72 having a diameter of 6 inches requiring an airflow of 750 cfm at the end of the slide 34 the seeds continue into the housing 36 containing the series of pin mill drums 38 referring specifically to fig6 the series of pin mill drums 38 is driven by a belt 78 turned by a motor 80 a timing drive connects all of the pin mill drums 38 and causes all the pin mill drums 38.