A, the production of portal frame:

1. material: spring steel wire, φ 2 ~ 2.5 mm in diameter (preferably φ 2.3), brand "6 W-Mn". Too thin to insert, too thick to increase the total weight, dozens of sets are too heavy to carry up the mountain.

2. Rack size (see figure):

There are two structures (see figure): one-piece and split.

3. Heat treatment after painting: keep the temperature at 350℃ ~ 380℃ for one hour, then naturally cool in the furnace, and finally finalize the design, correct and paint (black or brown is the best).

Second, the production of ferrule:

1. material: nylon winding (black or brown) or "Yulang" brand fishing line used in street shoe mending machine, which can be used to cut 580mm long single line;

2. Fold several single strands in half, tie a knot with a diameter of about 2 mm, and then twist it into a single ferrule strand with a diameter of 1 ~ 1.2 mm;

3. Make the steel strand into several 80mm single ferrules;

4. Set the completed single ferrule.

Third, the General Assembly:

After assembling the left and right portal frames as shown in the figure, install the ferrules in turn. As shown in the figure, the two groups of ferrules overlap each other with a diameter of 1/3, which is beneficial to improve the success rate. Most of me put two rings around the neck of the chicken at the same time, which is not easy to run off. This layout is my experience for many years, and I hope to learn from it. There is also a rule of thumb, that is, put a little oil on the steel wire bundle before tying the ferrule to the gantry. When gluing and fixing, turn the gluing part of the ferrule several times when the glue is not solidified, and remember not to hang it with the steel wire, which is beneficial to the setting and position adjustment in future use.