Abstract: The tie bar supporting a feed tray (moving mass) is attached to the reaction mass using one leaf spring and one elastomeric spring. The elastomeric spring comprises first and second elastomeric pads which sandwich a portion of the tie bar to which the feed tray is attached. The elastomeric spring operates in shear with the spring rate of the elastomeric spring being adjusted by increasing/decreasing the compressive force exerted by the first and second elastomeric pads on the tie bar. The adjustable vibratory feeder has demonstrated greatly enhanced stability over other existing systems.