Filament feeder

A filament feeder for use in an additive manufacturing system, comprising a main feeder body having mounted thereon a first roller assembly and a second roller assembly, the first and second roller assemblies being spaced apart along a feed trajectory of the filament feeder,

• wherein the first roller assembly comprises a first biasing roller and a driven first gripper roller, the first biasing roller and the first gripper roller being journaled for rotation and arranged at an adjustable first roller distance from each other allowing a filament material to be received between the first biasing roller and the driven first gripper roller,
• wherein the second roller assembly comprises a second biasing roller and a driven second gripper roller, the second biasing roller and second gripper roller being journaled for rotation and arranged at an adjustable second roller distance from each other allowing the filament material to be received between the second biasing roller and the driven second gripper roller,
• wherein each of the first and second gripper rollers is arranged for driven rotation in a direction corresponding to a feed direction in which the filament material is to be moved along the feed trajectory, and further comprising
• a single spring member having an adjustable length, the spring member being in resilient engagement with the first and second biasing rollers and configured to bias the first and second biasing roller toward the first and second gripper rollers, respectively, during an additive manufacturing process.