With the variable speed controller on and the proper level of parts in the bowl, set the dial at 35% to 40% of the input voltage. Some parts movement should be detected at this point. If the feed rate is too slow, increase the controller setting slowly until the desired feed rate is. Properly adjusting a vibratory bowl feeder is crucial for maintaining its efficiency and ensuring a smooth production process. When. This video guides you on how to correctly adjust the vibratory feeder bowl. How can we help you? This reference and.