2. Installation of space bean: bend the tied double hook line out of its suspension point according to the hook distance of 5CM, and install a space bean here to (temporarily) fix the point.
3. Winding: Tie the sub-wire into a big slipknot, and wind the double hook in the knot for 2 or 3 times respectively, find out about 3 times in the first circle, and clamp it with a small iron to form a hole. Then wrap the two hooks around a big circle, including the upper circle, and the two hooks should be wrapped around the same number of circles (15-20 circles each). In order to prevent entanglement between the two sides, use a small plastic clip to temporarily clamp it.
4. Tighten the coil: insert the small coil at the space bean into the hole clamped by the small iron clip, temporarily fix or hold down the nodule (about 2CM long) at the space bean with a small metal weight, and remove the three clips. Grasp the two hooks with both hands, and pull them in the left and right directions respectively, so as to tighten the knots wound in the previous step (15-20 turns each).