
Stop is hit the end of the shaft 6 in the recess of the washer 10, which is made of steel 45 and hardened. Due to the high strength of the washer and shaft, made of wire OVS Ø 3 mm, the service life of the stopper is almost unlimited.
Washer 5 covers the bearings from dust. To lubricate them quite a few drops of kerosene.

Fig. 1. Boss with the stopper in place.
1 — cone; 2 — hub; 3 — cone; 4 — spring; 5 — washer; 6 — shaft; 7 — ball bearing GOST 8338— 57; 8 — lug; 9 — rivet 10 — puck.

Fig. 2. Detail boss:
1 — cone (Art. 3); 3 — cone (L-16T); 5 — a washer (D-16T); 8 — boss (D-16T); 10 — washer (article 45, heat treatment, kalit, HRC—38÷41)
The hub 2 is made of wire OVS Ø 2,5 mm, spring, 4 — wire, EIA Ø 0.6 mm, the rivet 9 is made of aluminium wire Ø 1,5 mm. the end of the shaft 6, which is included in the bearings, for ease of the move should be smoothed out with sandpaper.
The weight of the structure Assembly 29-30 G.
Yu. a. GORSHKOV, Stavropol