Abstract: A method and apparatus for manufacturing fiber preforms includes a relatively small motor which is able to power a large fan because the fan is kept in a partial vacuum condition. A duct connects a fan housing to a vacuum box which has an air flow opening therein of relatively narrow width. A shuttle member is horizontally translatable above the vacuum box on a support bed and the shuttle member is divided into air flow channels by baffle plates. Only a small number of air flow channels can pass above the air flow opening at a single time and this serves to keep low pressure in the vacuum box. In addition, a vortex gate is provided in the duct between the fan housing and the vacuum box and serves to restrict air flow through the duct when the pressure within the duct drops below a certain level.