需要一个轴承(608ZZ)安装于针座和旋钮中间。转动时轴承运作,塑料不相互接触。尽量避免微塑料产生,食品类打印件更放心。"Requires a bearing (608ZZ) to be installed between the needle holder and the knob. The bearing operates during rotation, preventing plastic contact. Minimizing microplastic generation for increased confidence in food-grade prints."