Abstract: A hand-held three-dimensional drawing device can include an anti-rotation mechanism that can restrict rotation of a filament moving through the device. The anti-rotation mechanism can have a filament-engaging component in a passage of the anti-rotation mechanism and positioned to engage and restrict rotation a filament extending through the passage. The drawing device can also include a moveable member to control an operation of the drawing device. The moveable member can include a rotatable control mechanism including a portion of an outer profile of a housing of the device. Finally, the drawing device can also include a cover member comprising a portion of an outer profile of housing of the device and positioned adjacent to an actuator to control an operation of the device.