The Method Of Repairing Propeller Blades

1. Determine the scope of patching first, and mark the cutting and changing line on the blade and punch the hole;
2. Then measure the actual diameter of the propeller;
3. Cut the patching part, drill several holes outside the cutting and changing line, and then cut it, so that Z can be planed on the planer;
4. According to the shape of other complete leaves, make a wooden mold and fit the broken part properly, and ensure its diameter and screw surface shape. Z good is to make wood mold inlay according to the drawing size;
5. Drill and reshape the damaged corner on the drilling machine. Then use a chisel or air shovel to level the fracture;
6. Annealing treatment after welding to eliminate stress;
7. After casting, the patched blade shall be shaped and matched with the original blade, and the electric welding groove shall be processed at the same time;
8. Fix the patched blade with the original blade by pressing plate and bolt;
9. Preheating and welding;
10. Level and polish the weld scar protruding from the weld.
The shape of propeller blades also affects the performance. Two change the diameter, pitch or coupling of the propeller. Even if its diameter and pitch are the same, if it is manufactured by two manufacturers separately, its performance will be different. Make the engine run within the specified speed range when the throttle is fully open. Since there are many design variables and factors affecting the navigation performance of the boat, it is only through the water test that we can determine the required Z best in the current situation. If the engine speed cannot rise to the specified speed range when the throttle is fully open, the engine will struggle to produce full power.
In this case, the fuel consumption will increase significantly and the engine will overheat. If the engine speed exceeds the specified speed range, the internal parts of the engine will be severely worn and the engine will be scrapped prematurely. If the engine speed is lower than the rated speed, if the engine speed exceeds the specified speed. The pitch and/or diameter of the propeller should be reduced.
Changing the pitch of the propeller by one gear can increase or decrease the engine speed by 100~150 rpm. Determine whether the equipment is correct, arrange medium load on the boat, fully open the throttle when driving the boat, and measure the engine speed with a precision tachometer. The engine speed should be close to the upper limit of the specified speed range. In this way, when the heavy load is arranged on the boat, the engine speed will not fall below the specified speed range.