Particle feeder for spherical beads


This customized particle feeder is intended to feed large (>10 mm) spherical beads at a steady rate into a flume.  It is composed of the following components:

  • Stepper motor
  • Zeta 6104 motor controller
  • Shaft
  • Cylindrical "marble catcher" that rotates on shaft connected to motor at rate indicated by Zeta 6104 motor controller
  • Two PVC pipes, each with a diameter slightly larger than the two bead diameters
  • Funnel

The PVC pipes are mounted vertically above the rotating marble catcher.  The marble catcher is a cylindrical shaped piece of plastic with holes drilled on the side slightly larger than the bead sizes.  When these holes rotate past the vertically mounted PVC pipes, a bead drops in, one at a time, into the hole in the cylinder.  In this way, by controlling the RPM on the motor (via the motor controller) it is possible to precisely control the rate of entry of beads into the channel.  After each bead has been caught in the cylinder, the bead rotates with the cylinder until it drops into the funnel, from which it is release into the channel.The reason for custom designing the particle feeder (rather than using off-the-shelf screw or vibratory feeders) is that these do not perform well with large spherical particles.  Thus, we found it necessary to build this custom design.