Feeding and scalping are accomplished by football-shaped elliptical bars. Each elliptical bar is timed 90 degrees apart, meaning one bar tip is up and the next bar is rotated with the tip in a horizontal position. All bars rotate at the same rate of speed, moving loaded material along the bars until it discharges off the Wobbler.
Bars maintain a constant gap between themselves, allowing fines to pass through the bar gaps and discharging undersized scalped material. Crusher output can be increased by scalping material fines to let crushers handle only material that needs to be crushed.
Wobbler Feeders are self-cleaning, requiring minimal maintenance. Shot material can be dumped directly onto the Wobbler Feeder or fed using an Apron Feeder. Using an Apron Feeder and a Wobbler Feeder is often recommended as a combination to reduce impacting and increase the scalping area of the Wobbler.