Assemble instruction is in my youtube channel https://youtu.be/J8EjfcUJtvQ No extra parts needed, which are can't make with 3D printer such as metallic springs, bolts and etc. The parts are designed and tested to fit each other, however the tolerance is depends on a 3d-printer's condition. Please remove the supports completely. May need a sandpaper or cutter while assemble the parts.